Papers for Tuesday, Apr 30 2024

We present a concise report on the '2DHybrid' method, an innovative extension of two-dimensional correlation spectroscopy (2D COS), tailored for quasar light curve analysis. Addressing the challenge of discerning periodic variations against the background of intrinsic "red" noise fluctuations, this method employs cross-correlation of wavelet transform matrices to reveal distinct correlation patterns between underlaying oscillations, offering new insights into quasar dynamics.

The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL) facilities (from radio to gamma-ray energies) took part in the second M87 EHT campaign. The goal of this extensive MWL campaign was to better understand the physics of the accreting black hole M87*, the relationship between the inflow and inner jets, and the high-energy particle acceleration. Understanding the complex astrophysics is also a necessary first step towards performing further tests of general relativity. The MWL campaign took place in April 2018, overlapping with the EHT M87* observations. We present a new, contemporaneous spectral energy distribution (SED) ranging from radio to very high energy (VHE) gamma-rays, as well as details of the individual observations and light curves. We also conduct phenomenological modelling to investigate the basic source properties. We present the first VHE gamma-ray flare from M87 detected since 2010. The flux above 350 GeV has more than doubled within a period of about 36 hours. We find that the X-ray flux is enhanced by about a factor of two compared to 2017, while the radio and millimetre core fluxes are consistent between 2017 and 2018. We detect evidence for a monotonically increasing jet position angle that corresponds to variations in the bright spot of the EHT image. Our results show the value of continued MWL monitoring together with precision imaging for addressing the origins of high-energy particle acceleration. While we cannot currently pinpoint the precise location where such acceleration takes place, the new VHE gamma-ray flare already presents a challenge to simple one-zone leptonic emission model approaches, and emphasises the need for combined image and spectral modelling.

We present the first results on the spatial distribution of star formation in 454 star-forming galaxies at $4.8<z<6.5$ using H-Alpha emission-line maps and F444W imaging tracing the stellar continuum from the JWST FRESCO NIRCam Slitless Spectroscopy Survey. Star-forming galaxies with stellar masses $6.8\leq$log($M_{*}/\mathrm{M}_{\odot}$)$<11.1$ have positive H-Alpha equivalent width profiles, providing direct evidence for the inside-out growth of galaxies just after the epoch of reionisation. GALFIT is used to calculate half-light radii, $R_{\mathrm{eff}}$ and central surface densities within 1 kiloparsec, $\Sigma_{1\mathrm{kpc}}$ of H-Alpha and the continuum. At a fixed stellar mass of log$(M_{*}/\mathrm{M}_{\odot})=9.5$, $\Sigma_{1\mathrm{kpc, H}\alpha}$ is $1.3\pm0.1$ times higher than $\Sigma_{1\mathrm{kpc, C}}$ with consistent H-Alpha and continuum $R_{\mathrm{eff}}$ that are both less than 1 kpc. These measurements suggest the rapid build up of compact bulges without a significant increase in their radii. By comparing to work done at lower redshifts with HST WFC3 Slitless Spectroscopy as part of the 3D-HST ($z=1$) and CLEAR ($z=0.5$) surveys, we find that $R_{\mathrm{eff}}(z)$ and $\Sigma_{1\mathrm{kpc}}(z)$ evolve faster with redshift for H-Alpha. As a function of the Hubble parameter, $\frac{R_{\mathrm{eff, H}\alpha}}{R_{\mathrm{eff, C}}}=1.1h(z)^{-0.1}$ and $\frac{\Sigma_{1\mathrm{kpc,H}\alpha}}{\Sigma _{1\mathrm{kpc,C}}}=h(z)^{0.3}$. These functions indicate there is a transition point at $2<z<4$ where the inside-out growth of the disk starts to dominate over the inside-out growth of the bulge towards lower redshifts. This is supported by the redshift evolution in EW(H$\alpha$) profiles, where there is rapid increase in EW(H$\alpha$) with radius within the half-light radius at $z=5.3$ but only significantly increasing EW(H$\alpha$) with radius in the outer disk at $z=0.5$.

Radiative transfer (RT) is a crucial ingredient for self-consistent modelling of numerous astrophysical phenomena across cosmic history. However, on-the-fly integration into radiation-hydrodynamics (RHD) simulations is computationally demanding, particularly due to the stringent time-stepping conditions and increased dimensionality inherent in multi-frequency collisionless Boltzmann physics. The emergence of exascale supercomputers, equipped with extensive CPU cores and GPU accelerators, offers new opportunities for enhancing RHD simulations. We present a novel optimization of AREPO-RT explicitly tailored for such high-performance computing environments. We implement a novel node-to-node communication strategy that utilizes shared memory to substitute intra-node communication with direct memory access. Furthermore, combining multiple inter-node messages into a single message substantially enhances network bandwidth utilization and performance for large-scale simulations on modern supercomputers. The single-message node-to-node approach also improves performance on smaller-scale machines with less optimized networks. Furthermore, by transitioning all RT-related calculations to GPUs, we achieve a significant computational speedup of around 15 for standard benchmarks compared to the original CPU implementation. As a case study, we perform cosmological RHD simulations of the Epoch of Reionization, employing a similar setup as the THESAN project. In this context, RT becomes sub-dominant such that even without modifying the core AREPO codebase, there is an overall threefold improvement in efficiency. The advancements presented here have broad implications, potentially transforming the complexity and scalability of future simulations for a wide variety of astrophysical studies.

Ultra-high-energy cosmic rays, accelerated hadrons that can exceed energies of $10^{20}$ eV, are the highest-energy particles ever observed. While the sources producing UHECRs are still unknown, the Pierre Auger Observatory has detected a large-scale dipole anisotropy in the arrival directions of cosmic rays above 8 EeV. In this work, we explore whether resolved gamma-ray sources can reproduce the Auger dipole. We use various Fermi Large Area Telescope catalogs as sources of cosmic rays in CRPropa simulations. We find that in all cases, the simulated dipole has an amplitude significantly larger than that measured by Auger, even when considering large extragalactic magnetic field strengths and optimistic source weighting schemes. Our result implies that the resolved gamma-ray sources are insufficient to account for the population of sources producing the highest-energy cosmic rays, and there must exist a population of UHECR sources that lack gamma-ray emission or are unresolved by the current-generation gamma-ray telescopes.

The most active phases of star formation and black hole accretion are strongly affected by dust extinction, making far-infrared (far-IR) observations the best way to disentangle and study the co-evolution of galaxies and super massive black holes. The plethora of fine structure lines and emission features from dust, ionised and neutral atomic and warm molecular gas in the rest-frame mid- and far-IR provide unmatched diagnostic power to determine the properties of gas and dust, measure gas-phase metallicities and map cold galactic outflows in even the most obscured galaxies. By combining multi-band photometric surveys with low and high-resolution far-IR spectroscopy, the PRobe far-Infrared Mission for Astrophysics (PRIMA), a concept for a far-IR, 1.8m-diameter, cryogenically cooled observatory, will revolutionise the field of galaxy evolution by taking advantage of this IR toolkit to find and study dusty galaxies across galactic time. In this work, we make use of the phenomenological simulation SPRITZ and the Santa Cruz semi-analytical model to describe how a moderately deep multi-band PRIMA photometric survey can easily reach beyond previous IR missions to detect and study galaxies down to $10^{11}\,L_{\odot}$ beyond cosmic noon and at least up to z=4, even in the absence of gravitational lensing. By decomposing the spectral energy distribution (SED) of these photometrically selected galaxies, we show that PRIMA can be used to accurately measure the relative AGN power, the mass fraction contributed by polycyclic aromatic hydrocarbon (PAH) and the total IR luminosity. At the same time, spectroscopic follow up with PRIMA will allow to trace both the star formation and black hole accretion rates (SFR, BHAR), the gas phase metallicities and the mass outflow rates of cold gas in hundreds to thousands of individual galaxies to z=2.

We present a catalog of hard X-ray serendipitous sources detected in the first 80 months of observations by the Nuclear Spectroscopic Telescope Array (NuSTAR). The NuSTAR serendipitous survey 80-month (NSS80) catalog has an unprecedented $\sim$ 62 Ms of effective exposure time over 894 unique fields (a factor of three increase over the 40-month catalog), with an areal coverage of $\sim $36 deg$^2$, larger than all NuSTAR extragalactic surveys. NSS80 provides 1274 hard X-ray sources in the $3-24$ keV band (822 new detections compared to the previous 40-month catalog). Approximately 76% of the NuSTAR sources have lower-energy ($<10$ keV) X-ray counterparts from Chandra, XMM-Newton, and Swift-XRT. We have undertaken an extensive campaign of ground-based spectroscopic follow-up to obtain new source redshifts and classifications for 427 sources. Combining these with existing archival spectroscopy provides redshifts for 550 NSS80 sources, of which 547 are classified. The sample is primarily composed of active galactic nuclei (AGN), detected over a large range in redshift ($z$ = 0.012-3.43), but also includes 58 spectroscopically confirmed Galactic sources. In addition, five AGN/galaxy pairs, one dual AGN system, one BL Lac candidate, and a hotspot of 4C 74.26 (radio quasar) have been identified. The median rest-frame $10-40$ keV luminosity and redshift of the NSS80 are $\langle{L_\mathrm{10-40 keV}}\rangle$ = 1.2 $\times$ 10$^{44}$ erg s$^{-1}$ and $\langle z \rangle = 0.56$. We investigate the optical properties and construct composite optical spectra to search for subtle signatures not present in the individual spectra, finding an excess of redder BL AGN compared to optical quasar surveys predominantly due to the presence of the host-galaxy and, at least in part, due to dust obscuration.

The formation redshift and abundance of the first stars and galaxies is highly sensitive to the build up of low mass dark matter halos as well as astrophysical feedback effects which modulate star formation in these low mass halos. The 21-cm signal at cosmic dawn will depend strongly on the formation of these first luminous sources and thus can be used to constrain unknown astrophysical and dark matter properties in the early universe. In this paper, we explore how well we could measure properties of dark matter using the 21-cm power spectrum at $z>10$, given unconstrained astrophysical parameters. We create a generalizable form of the dark matter halo mass function for models with damped and/or oscillatory linear power spectra, finding a single "smooth-k" window function which describes a broad range of models including CDM. We use this to make forecasts for structure formation using the Effective Theory of Structure Formation (ETHOS) framework to explore a broad parameter space of dark matter models. We make predictions for the 21-cm power spectrum observed by HERA varying both cosmological ETHOS parameters as well as astrophysical parameters. Using a Markov Chain Monte Carlo forecast we find that the ETHOS dark matter parameters are degenerate with astrophysical parameters linked to star formation in low mass dark matter halos but not with X-ray heating produced by the first generation of stars. After marginalizing over uncertainties in astrophysical parameters we demonstrate that with just 540 days of HERA observations it should be possible to distinguish between CDM and a broad range of dark matter models with suppression at wavenumbers $k\lesssim 200\,h$Mpc$^{-1}$ assuming a moderate noise level. These results demonstrate the potential of 21-cm observations to constrain the matter power spectrum on scales smaller than current probes.

Numerous models of neutron star (NS) equation of state (EoS) exist based on different superdense-matter physics approaches. Nevertheless, some NS properties show universal (EoS-independent) relations. Here, we propose a novel class of such universalities. Despite different physics inputs, a wide class of realistic nucleonic, hyperonic, and hybrid EoS models can be accurately described using only three parameters. For a given EoS, these are the mass and radius of the maximum-mass NS (or pressure and density in its center) and the radius of a half-maximum-mass star. With such a parametrization, we build universal analytic expressions for mass-radius and pressure-density relations. They form a semi-analytic mapping from the mass-radius relation to the EoS in NS cores (the so-called inverse Oppenheimer-Volkoff mapping). This mapping simplifies the process of inferring the EoS from observations of NS masses and radii. Applying it to current NS observations we set new limits on the high end of the EoS.

The Spectroscopic Investigation of Nebular Gas (SING) is a near-ultraviolet (NUV) low-resolution spectrograph payload designed to operate in the NUV range, 1400 $\unicode{x212B}$ -- 2700 $\unicode{x212B}$, from a stable space platform. SING telescope has a primary aperture of 298 mm, feeding the light to the long-slit UV spectrograph. SING has a field of view (FOV) of 1$^{\circ}$, achieving a spatial resolution of 1.33 arc minute and spectral resolution of 3.7 $\unicode{x212B}$ ($R\sim600$) at the central wavelength. SING employs a micro-channel plate (MCP) with a CMOS readout-based photon-counting detector. The instrument is designed to observe diffuse sources such as nebulae, supernova remnants, and the interstellar medium (ISM) to understand their chemistry. SING was selected by the United Nations Office for Outer Space Affairs to be hosted on the Chinese Space Station. The instrument will undergo qualification tests as per the launch requirements. In this paper, we describe the hardware design, optomechanical assembly, and calibration of the instrument.

We study the dynamics of a non-minimally coupled (NMC) scalar spectator field in non-oscillatory inflationary scenarios, where there is a transition from inflation to kination domination (KD). Engineering a realistic finite-duration transition through a CMB-compatible inflaton potential, we calculate the initial tachyonic growth of the NMC field during KD and perform lattice simulations of the subsequent non-linear dynamics. We characterize the regularization effect on the tachyonic growth, either due to self-interactions, or via gravitational backreaction when the NMC field grows to dominate the energy of the universe. Our study provides the first realistic treatment of the dynamics, with significant improvements compared to previous work, where one or more of the following aspects were assumed: ($i$) the background expansion can be neglected during the tachyonic growth, ($ii$) coherence of the NMC field, ($iii$) coherence of the inflaton, ($iv$) instantaneous transition, and ($v$) a KD equation of state of exactly $w = 1$. Using our methodology, which requires none of the above assumptions, we determine the conditions to achieve proper reheating, i.e. energetic dominance of the NMC field over the inflaton. We characterize the time and energy scales of the problem, either for backreaction due to self-interactions, or (as a novelty of this work) due to gravitational effects. Finally, we calculate $\mathcal{O}(1)$ lattice correction factors to analytic scaling relations derived by some of us in previous work. This enables simple future studies without the need to run lattice simulations.

Recent JWST eclipse spectra of the high-density hot Saturn HD 149026b between 2.35 and 5.08 $\mu$m has allowed for in-depth study of its atmosphere. To understand its atmospheric properties, we have created a grid of 1D radiative-convective-thermochemical equilibrium atmosphere models and spectra with PICASO 3.0. In agreement with previous work, we find that the presence of gaseous TiO creates a thermal inversion, which is inconsistent with the data. The presence of gaseous VO, however, which condenses at temperatures 200 K cooler, does not cause such inversions but alters the temperature-pressure profile of the atmosphere. We estimate an atmospheric metallicity of $14^{+12}_{-8}\times$ solar without VO and $20^{+11}_{-8}\times$ solar with VO, a factor of $\sim 10$ times smaller than previous work from Bean et al. (2023), who relied on atmosphere retrievals. We attribute this significant difference in metallicity to a larger temperature gradient at low pressures in radiative equilibrium models. Such models with lower metallicities readily fit the strong CO$_2$ feature at 4.3 $\mu$m. Our lower estimated metallicity makes HD 149026b more consistent with the mass-metallicity relationship for other giant planets. We find a C/O ratio of $0.67^{+0.06}_{-0.27}$ with and without VO. The best-fit heat redistribution factor without VO is $1.17$, a very high value suggesting very little dayside energy transport and no energy transport to the night side. The heat redistribution factor shrinks to a more plausible value of $0.91^{+0.05}_{-0.05}$, with VO, which we regard as circumstantial evidence for the molecule in the atmosphere of HD 149026b.

Radiation pressure exerted by solar photon output is salient to the motion of primary neutral hydrogen atoms streaming into the inner heliosphere directly from the Local Interstellar Medium (LISM). The action of a time-dependent radiation pressure force, when coupled with the usual gravitational force, changes the characteristic velocities, and therefore energies, of the atoms when they reach regions in which explorer probes are present. A study is presented that uses a 2D code to backtrace neutral hydrogen trajectories from representative target points located 1 au from the Sun. It makes use of both a radiation pressure function and a function for the photoionization rate at 1 au that oscillate with time based on measurements over a typical solar cycle, as well as a time-independent charge exchange ionization rate at 1 au. Assuming a Maxwellian distribution in the distant upwind direction, phase space data is calculated at the target points, at different moments in time. The dependence of the force on the radial particle velocity has been omitted in the analysis, such that the emphasis is on the effects of the global solar UV intensity variations through the solar cycle. This process allows for analysis of direct and indirect Maxwellian components through time and space in the time-dependent force environment. Additionally, pseudo-bound orbits caused by energy losses associated with this force environment are observed and their properties evaluated with the aim of determining their effects on potential measurements by explorer probes.

We implement an algorithm based on the weighted stacking of astronomical images that can combine different observations of the same region of the sky removing the interfering signals. We develop a C++ code that takes as input a set of spectral cubes and computes the local weights of the intensity for each pixel of every channel. The weights are calculated as the inverse variance of the nearby pixels and are used to compute the weighted merge of the input files. Astronomical sources, present in all cubes, are preserved by the weighted average. However, interfering signals, present in specific cubes and a certain frequency range, are down-weighted in the average and removed from the output spectral cube. We present the results obtained by analyzing simulated spectral cubes containing astronomical sources, noise, and a random set of interferences of different intensities and spectral occupations. The performance of the algorithm is evaluated by comparing the output result with the input sky model image. Finally, we present the results obtained by applying the method to a set of real data consisting of observations of the Andromeda galaxy, Messier 31 (M31), at 6.6 GHz obtained with the Sardinia Radio Telescope.

We write to report the discovery that Deneb is a large amplitude polarization variable. Over a ~400 d time span from August 2022 Deneb's polarization was typically around 3900 parts-per-million (ppm) in the SDSS g'-band. Yet, it varied by several hundred ppm in an irregular way on a timescale of weeks. The largest polarization change, amounting to 2500 ppm, occurred shortly after the last pulsation ``resumption'' event identified by Abt et al. (2023) in TESS photometry. The relationship between the observed polarization -- particularly corresponding to the resumption event -- and its brightness and H-alpha spectra suggests a mechanism involving density changes in its wind and/or extended atmosphere. Smaller effects due to pulsations are not ruled out and further study is recommended.

We present an analysis of high-dispersion spectroscopic observations of the symbiotic system R Aquarii (R Aqr) obtained with the Manchester Echelle Spectrograph (MES) at the 2.1 m telescope of the San Pedro M\'artir Observatory (Mexico). An interpretation of these data is presented by means of the shape software to disclose the morpho-kinematics of the nebulosities associated with R Aqr. The best model that reproduces narrow-band images and position-velocity diagrams is composed by three structures: an outer (large) hourglass structure surrounding an inner bipolar with a spiral-like filament entwined around the later. Different expansion velocity patterns are predefined for each structure, which predict kinematic ages of $\tau_{1}$=450$\pm$25 yr (outer hourglass), $\tau_{2}$=240$\pm$20 yr (inner bipolar) and $\tau_{3}$=215$\pm$20 yr (spiral-like filament). We suggest that the spiral-like filament is tracing the regions of interaction of the precessing jet with the circumstellar material, which simultaneously carves the inner bipolar structure. If a similar process created the large hourglass structure, it means that the action of the jet ceased for about 230 yr. We discuss the implication for other unresolved symbiotic systems detected in X-rays.

In this work, we search the OGLE-IV outer Galactic bulge fields for short-period variable objects. The investigation focuses on unexplored timescales roughly below one hour in an area containing about 700 million stellar sources down to approximately I=20 mag. We concentrate mainly on Blue Large-Amplitude Pulsators (BLAPs), which represent a recently discovered enigmatic class of short-period hot subluminous stars. We find 33 BLAPs in the period range from 7.5 to 66.5 min. Thirty-one of them are new discoveries, which increases the number of known stars of this class to over one hundred. Additional eighteen objects with pulsation-like light curve shapes and periods ranging from 17.3 to 53.7 min are presented. Very likely, these are $\delta$ Sct/SX Phe-type stars, but some of them could be pulsating hot subdwarfs or BLAPs. We also report on the detection of five eclipsing binary systems with orbital periods between 61.2 and 121.9 min and three mysterious variable objects with I-band amplitudes larger than 0.9 mag. A spectroscopic follow-up would help in the final classification of the variables.

In the last decade, the multi-sensory approach to data analysis has gained relevance. The possibility of including people with vision difficulties in the field of education and the dissemination of science is part of it. However, in the field of scientific research, the topic is not yet accepted, mainly due to the lack of conclusive evidence related to its robustness and performance, except for a few exceptions. On the other hand, very few of the tools that allow data to be sonifyed are focused on the user or have an interface that allows controlling the sound production process and, at the same time the visualization of data. Of those that meet this requirement and present application in the field of astronomy and astrophysics, only four have included people with visual disabilities in the design and only two of them have carried out tests with users in Focus Groups during its development. This work details the characteristics of sonoUno, with its end-user-focused design, its capabilities in specific use cases in astrophysical data analysis related to spectroscopy and photometry, following the basic software functionalities while also introducing some innovation.

Giant radio galaxies (GRGs, giant RGs, or giants) are megaparsec-scale, jet-driven outflows from accretion disks of supermassive black holes, and represent the most extreme pathway by which galaxies can impact the Cosmic Web around them. A long-standing but unresolved question is why giants are so much larger than other radio galaxies. It has been proposed that, in addition to having higher jet powers than most RGs, giants might live in especially low-density Cosmic Web environments. In this work, we aim to test this hypothesis by pinpointing Local Universe giants and other RGs in physically principled, Bayesian large-scale structure reconstructions. More specifically, we localised a LOFAR Two-metre Sky Survey (LoTSS) DR2-dominated sample of luminous ($l_\nu(\nu = 150\ \mathrm{MHz}) \geq 10^{24}\ \mathrm{W\ Hz^{-1}}$) giants and a control sample of LoTSS DR1 RGs, both with spectroscopic redshifts up to $z_\mathrm{max} = 0.16$, in the BORG SDSS Cosmic Web reconstructions. We measured the Cosmic Web density for each RG; for the control sample, we then quantified the relation between RG radio luminosity and Cosmic Web density. With the BORG SDSS tidal tensor, we also measured for each RG whether the gravitational dynamics of its Cosmic Web environment resemble those of clusters, filaments, sheets, or voids. Luminous giants populate large-scale environments that tend to be denser than those of general RGs. This shows that -- at least at high jet powers -- low-density environments are no prerequisite for giant growth. This result is corroborated by gravitational dynamics classification and a cluster catalogue crossmatching analysis. This work presents more than a thousand inferred megaparsec-scale densities around radio galaxies. Our findings are consistent with the view that giants are regular, rather than mechanistically special, members of the radio galaxy population.

The initial power spectrum of density perturbations, generated during the inflationary epoch, is now constrained by observations on scales $\lambda>5$~Mpc and has a power-law form. The peculiarities of the inflationary process can lead to the appearance of non-power-law contributions to this spectrum, such as peaks. The exact size and shape of the peak cannot be predicted in advance. In this paper, we propose methods for searching for such peaks in the region of the spectrum with $\lambda<5$~Mpc. Perturbations on these scales enter the nonlinear stage at $z\gtrsim10$, which is now becoming accessible to observations. Our studies of numerical models of large-scale structure with peaks in the initial spectrum have shown that spectral features on scales with $\lambda>0.1$~Mpc manifest in the clustering of galaxies, as well as affect their mass function, sizes, and density. Studying these characteristics of distant galaxies will allow us to constrain cosmological models with peaks.

Planet-forming disks turn from gas-rich, massive disks made of dust and gas into planetary systems containing only small amounts dust produced by collisions between smaller planetary objects like planetesimals, asteroids, or comets. Traditionally we talk about protoplanetary (age $\sim$1 Myr), transitional ($\sim$ 5-10 Myr), and debris disks ($\sim$ 10-hundreds of Myr), even though the overlap between these phases may be relevant. We aim to show that in the transition phase of a disk, when gas surface densities are reduced but not yet negligible, a seemingly small amount of collisional activity may lead to the production of dust on a level that is observationally relevant by creating regions of optical depth 1 or above. In particular, we aim to show that the hot dust emission component of transitional disks may in fact be debris dust produced in such collisions. We develop an analytical model to derive the conditions under which observationally relevant amounts of dust can be produced. We focus on the effect of the gas surface density during the transition phase of a disk from fully gas-dominated to the gas-poor debris stage. We show that the decrease of the gas surface density has an important effect. It allows smaller planetesimals to become collisional, starting a cascade. At the same time, small particles are not destroyed by collisions. That interrupted cascade is critical to preserve the produced dust for significant time intervals, allowing a seemingly minor amount of planetesimal collisions to be effective in producing detectable amounts of dust. The warm emission of low amounts of dust in many transitional planet-forming disks might be caused entirely by second-generation dust, exposing planetary material at a time much earlier than the age of what are traditionally considered as debris disks.

The rotation curve is significant to research on dark matter and the structure of the Milky Way. But it is a great challenge to measure rotation curve accurately, and different ways obtain distinct results. In this work, we use a DIY small radio telescope to carry out hydrogen 21-cm line observations on campus, and calculate the rotation curve of inner disk by tangent method based on the model of Przemek et al. (the rotation speed of the Sun $v(R_0)=233.6\pm2.8$ km/s, and distance to the Galactic center $R_0=8.122\pm0.031$ kpc). Furthermore, we obtain the distribution of spiral arms in the Milky Way with our data by adopting different rotation curve models. We also compare our rotation curve result with previous works, analyse the possible measurement error in the tangent method, and discuss the consistence of our result with others.

Radio Frequency Interference (RFI) is emitted from various sources, terrestrial or orbital, and create a nuisance for ground-based 21cm experiments. In particular, single-dish 21cm intensity mapping experiments will be highly susceptible to contamination from these sources due to its wide primary beam and sensitivity. This work aims to simulate the contamination effects emitted from orbital sources in the Radio Navigational Satellite System within the 1100-1350 MHz frequency. This simulation can be split into two parts: (I) satellite positioning, emission power, and beam response on the telescope and (II) fitting of the satellite signal to data in order to improve the original model. We use previously observed single dish MeerKAT L-band data which needs to be specially calibrated to include data contaminated by satellite-based RFI. We find that due to non-linearity effects, it becomes non-trivial to fit the satellite power. However, when masking regions where this non-linearity is problematic, we can recreate the satellite contamination with high accuracy around its peak frequencies. The simulation can predict satellite movements and signal for past and future observations, which can help in RFI avoidance and testing novel cleaning methods. The predicted signal from simulations sits below the noise in the target cosmology window for the L-band (970 - 1015 MHz) making it difficult to confirm any out-of-band emission from satellites. However, a power spectrum analysis shows that such signal can still contaminate the 21cm power spectrum at these frequencies. In our simulations, this contamination overwhelms the auto-power spectrum but still allows for a clean detection of the signal in cross-correlations with mild foreground cleaning. Whether such contamination does exist one will require further characterization of the satellite signals far away from their peak frequencies.

GRB 211211A is a peculiar long Gamma-ray burst (GRB) with very high brightness and short burst properties. It's full lightcurve consists of three emission episodes, i.e. a precursor, a main burst and a extended emission. We find a recently detected long-duration GRB 230307A also includes the three consistent emission episodes. Furthermore, the two bursts have similar redshift 0.076 and 0.065, respectively. We perform a detail temporal and spectral analysis of the two GRBs to compare their temporal and spectral properties. Our analysis shows that the two bursts share great similarities for both the whole emission and the three corresponding emission phases, which are listed as follows: (1) they have near zero spectral lag, (2) they have very short minimum variability timescale (MVT), (3) they lie in the same region of in the MVT-$T_{90}$, Amati relation, and hardness-$T_{90}$ planes, (4) the three phases are quasi-thermal spectra, (5) both the peak energy and the low-energy index track the flux, (6) the time-resolved spectra are much wider than those of the blackbody prediced by theory model, (7) there are strong correlations between thermal flux and total flux and the correlation coefficients as well as the slopes for the corresponding stages are very consistent, (8) the photosphere emission properties are very consistent. Other investigations and observations suggest the two GRBs indeed belong to short burst with a compact star merger origin. Therefore, we think that GRB 230307A and GRB 211211A are the rare and similar GRBs and the photospheric radiation can interpret their radiation mechanisms.

We postprocess a three-dimensional general relativistic, full transport neutrino radiation magnetohydrodynamics simulation of the black hole--accretion disk--wind system thought to be a potential outcome of the GW170817 merger to investigate the presence of electron lepton number (ELN-XLN) crossings in the neutrino angular distribution. Neutrinos are evolved with an explicit Monte Carlo method and can interact with matter via emission, absorption, or scattering. Within the postprocessing framework, we find ubiquitous occurrence of ELN-XLN crossings at early times ($\sim$ 11ms) but this does not hold for later times in the simulation. At postmerger times of $ \sim$ 60 ms and beyond, ELN-XLN crossings are only present near the equator. We provide a detailed analysis of the neutrino radiation field to investigate the origin and time evolution of these crossings. Previous reports have suggested ubiquitous flavor crossings persisting throughout the simulation lifetime, albeit for different sets of conditions for the merger remnant, the treatment of hydrodynamics and neutrino transport. Even though we do not perform a direct comparison with other published works, we qualitatively assess the reasons for the difference with our results. The geometric structure and evolution of the ELN-XLN crossings found in our analysis, and by extension, fast flavor instabilities have important implications for heavy element nucleosynthesis in neutron star mergers.

Massive quiescent galaxies in the young universe are expected to be quenched rapidly, but it is unclear whether they all experience starbursts before quenching and what physical mechanism drives rapid quenching. We study 16 massive quiescent galaxies ($\log(M_\star/M_\odot) > 10$) at $z\sim2$ selected from a representative sample of the Blue Jay survey. We reconstruct their star formation histories by fitting spectral energy distribution models to the JWST/NIRSpec $R\sim1000$ spectra. We find that massive quiescent galaxies can be split into three categories with roughly equal numbers of galaxies according to their SFHs: 1) Relatively old galaxies quenched at early epochs; 2) Galaxies that are rapidly and recently quenched after a flat or bursty formation history (depending on the assumed prior); 3) Galaxies that are rapidly and recently quenched after a major starburst. Most recently quenched galaxies show neutral gas outflows, probed by blueshifted $\rm Na\,I\,D$ absorption, and ionized gas emission, with line ratios consistent with active galactic nucleus (AGN) diagnostics. This suggests that AGN activity drives multi-phase gas outflows, leading to rapid quenching. By tracing back the SFHs of the entire sample, we predict the number density of massive quiescent galaxies at $z=4-6$: $n=3.0\pm1.4\times10^{-5}\,\rm Mpc^{-3}$. The two oldest massive quiescent galaxies in our sample appear to have extremely early formation and quenching ($z\gtrsim6$), possibly descendants of early post-starbursts at $z>3$. These galaxies still show neutral gas reservoirs and low-level star formation, consistent with weak H$\alpha$ emission, perhaps because the ejective AGN feedback that caused rapid quenching has weakened over time.

We present a study of hydrogen, helium, and carbon millimeter-wave radio-recombination lines (RRLs) toward ten representative positions throughout the Orion Nebula complex, using the Yebes 40m telescope in the Q band (31.3 GHz to 50.6 GHz) at an angular resolution of about $45\arcsec$ ($\sim$0.09\,pc). The observed positions include the Orion Nebula (M42) with the Orion Molecular Core 1, M43, and the Orion Molecular Core 3 bordering on NGC 1973, 1975, and 1977. While hydrogen and helium RRLs arise in the ionized gas surrounding the massive stars in the Orion Nebula complex, carbon RRLs stem from the neutral gas of the adjacent photo-dissociation regions (PDRs). The high velocity resolution ($0.3\,\mathrm{km\,s^{-1}}$) enables us to discern the detailed dynamics of the RRL emitting neutral and ionized gas. We compare the carbon RRLs with SOFIA/upGREAT observations of the [CII] $158\,\mu\mathrm{m}$ line and IRAM 30m observations of the $^{13}$CO (J=2-1) line. Using the [CII] and [$^{13}$CII] intensities with the carbon RRL intensities, we can infer physical conditions (electron temperature and electron density) in the PDR gas using non-LTE excitation models. Our observations are sensitive enough to detect faint lines toward two positions in OMC1, that may be attributed to RRLs of C$^+$ or O$^+$. In general, the RRL line widths of both the ionized and neutral gas, as well as the [CII] and $^{13}$CO line widths, are broader than thermal, indicating significant turbulence in the interstellar medium, which transitions from super-Alfv\'enic and subsonic in the ionized gas to sub-Alfv\'enic and supersonic in the molecular gas. At the scales probed by our observations, the turbulent pressure dominates the pressure balance in the neutral and molecular gas, while in the ionized gas the turbulent pressure is much smaller than the thermal pressure.

The emergence of the James Webb Space Telescope and the development of other advanced observatories (e.g., ELTs, LIFE and HWO) marks a pivotal moment in the quest to characterize the atmospheres of Earth-like exoplanets. Motivated by these advancements, we conduct theoretical explorations of exoplanetary atmospheres, focusing on refining our understanding of planetary climate and habitability. Our study investigates the impact of ozone on the atmosphere of Proxima Centauri b in a synchronous orbit, utilizing coupled climate chemistry model simulations and dynamical systems theory. The latter quantifies compound dynamical metrics in phase space through the inverse of co-persistence ($\theta$) and co-dimension (d), of which low values correspond to stable atmospheric states. Initially, we scrutinized the influence of ozone on temperature and wind speed. Including interactive ozone (i.e., coupled atmospheric (photo)chemistry) reduces the hemispheric difference in temperature from 68 K to 64 K, increases ($\sim+$7 K) atmospheric temperature at an altitude range of $\sim$20-50 km, and increases variability in the compound dynamics of temperature and wind speed. Moreover, with interactive ozone, wind speed during highly temporally stable states is weaker than for unstable ones, and ozone transport to the nightside gyres during unstable states is enhanced compared to stable ones ($\sim+$800 DU). We conclude that including interactive ozone significantly influences Earth-like exoplanets' chemistry and climate dynamics. This study establishes a novel pathway for comprehending the influence of photochemical species on the climate dynamics of potentially habitable Earth-like exoplanets. We envisage an extension of this framework to other exoplanets.

With three-dimensional hydrodynamical simulations we show that the size of the decretion disc and the structure of the accretion flow onto the neutron star in a Be/X-ray binary strongly depends upon the disc aspect ratio, $H/R$. We simulate a Be star disc that is coplanar to the orbit of a circularly or moderately eccentric neutron star companion, thereby maximising the effects of tidal truncation. For low disc aspect ratio, $H/R\lesssim 0.1$, the disc is efficiently tidally truncated by the neutron star. Most material that escapes the Roche lobe of the Be star is accreted by the neutron star through tidal streams. For larger disc aspect ratio, the outflow rate through the Be star disc is higher, tidal truncation becomes inefficient, the disc fills the Roche lobe and extends to the orbit of the companion. Some material escapes the binary as a gas stream that begins near the L2 point. While the accretion rate onto the neutron star is higher, the fraction of the outflow that is accreted by the neutron star is smaller. Low density Be star discs are expected to be approximately isothermal, such that $H/R$ increases with radius. Tidal truncation is therefore weaker for larger separation binaries, and lower mass primaries.

Presently, it is unclear whether the Eddington ratio and radiative efficiency depend upon a supermassive black hole's (SMBH's) redshift z and mass MBH. We attempt to resolve this issue using published data for 132,000 SMBHs with MBH >1E+7 Msun (solar masses) at ~0.1<z<2.4 covering ~10 billion years of cosmic time, with MBH determined using MgII lines and bolometric luminosities (Lbol) based on a weighted mean of Lbol from two or more monochromatic luminosities and a single uniformly applied correction factor. The SMBHs are sorted into 7 MBH bins separated from each other by half an order of magnitude. The Eddington ratio and z data in each bin are subjected to spline regression analysis. The results unambiguously show that for similar-size SMBHs, the Eddington ratio decreases as z decreases and that for a given redshift larger SMBHs have a lower Eddington ratio. These findings require that either a SMBH's accretion rate and/or its radiative efficiency be a function of z and MBH and, in the context of the Bondi accretion model, imply that radiative efficiency is an inverse function of a SMBH's redshift z and mass MBH. These findings suggest that SMBHs become less efficient (higher radiative efficiency) in accreting gases as the ambient gas density decreases with z and that larger SMBHs are more efficient (lower radiative efficiency) than smaller ones. The results leave little doubt that the current widespread practice of assigning radiative efficiency a standard value is untenable and gives erroneous estimates of accretion rates and growth times of SMBHs.

We report the serendipitous discovery of a $8' \times 12'$ emission shell brightest in [O III] centered on the X-ray binary B[e] star, CI Cameleopardalis (CI Cam). This shell, detected during a survey of optical emission associated with the Galactic supernova remnant G150.3+4.5, is seen outside but immediately adjacent to the remnant's optical filaments along its northwestern edge. Assuming this shell is related to CI Cam's strong winds and transient outbursts, the adoption of CI Cam's Gaia DR3 statistically corrected distance of 4.1$^{+0.3}_{-0.2}$ kpc yields shell dimensions $\simeq$ 9.5 pc $\times$ 14.3 pc. While the distance to the G150.3+4.5 remnant is uncertain, the appearance of CI Cam's emission shell so close to the SNR's optical filaments appears likely to be a chance coincidence.

We summarize the current best polychromatic (10 to 20 % bandwidth) contrast performance demonstrated in the laboratory by different starlight suppression approaches and systems designed to directly characterize exoplanets around nearby stars. We present results obtained by internal coronagraph and external starshade experimental testbeds using entrance apertures equivalent to off-axis or on-axis telescopes, either monolithic or segmented. For a given angular separation and spectral bandwidth, the performance of each starlight suppression system is characterized by the values of raw contrast (before image processing), off-axis (exoplanet) core throughput, and post-calibration contrast (the final 1 sigma detection limit of off-axis point sources, after image processing). To place the current laboratory results in the perspective of the future Habitable Worlds Observatory (HWO) mission, we simulate visible observations of a fiducial Earth/Sun twin system at 12 pc, assuming a 6m (inscribed diameter) collecting aperture and a realistic end-to-end optical throughput. The exposure times required for broadband exoearth detection (20% bandwidth around a wavelength of 0.55 microns) and visible spectroscopic observations (R=70) are then computed assuming various levels of starlight suppression performance, including the values currently demonstrated in the laboratory. Using spectroscopic exposure time as a simple metric, our results point to key starlight suppression system design performance improvements and trades to be conducted in support of HWO exoplanet science capabilities. These trades may be explored via numerical studies, lab experiments, as well as high contrast space-based observations and demonstrations.

Rapidly spinning magnetars are potential candidates for the energy source of supernovae (SNe) and gamma-ray bursts and the most promising sources for continuous gravitational waves (GWs) detected by ground-based GW detectors. Continuous GWs can be radiated from magnetars due to magnetic-induced deformation or fluid oscillations, compatible with magnetic dipole (MD) radiation for spin-down energy. In this paper, we investigate the diverse light curves of magnetar-driven SNe in the scenario that the spin-down is dominated by GW radiation and/or MD radiation. By simulating the light curves of SNe and employing the Markov chain Monte Carlo method, we constrain the parameters of the magnetars and SN explosions and show that the signature of GW radiation may be indicated by the bolometric luminosity curves of SNe Ic-BL 2007ru and 2009bb. We find that the ellipticity of magnetars in the order of $10^{-3}$ can be induced by the magnetic field of $\sim 10^{16} \mbox{ G}$. If such continuous GWs associated with SNe can be detected in the future by the Advanced LIGO and Virgo detectors, this would be a smoking gun for a magnetar engine powering SNe.

The gas distribution in galaxies is smooth on large scales but is usually inhomogeneous as well as time-dependent on smaller scales. The time-dependence originates from processes such as cloud formation, their collisions and supernovae (SNe) explosions. The inhomogeneities in the matter distribution give rise to variations in the local galactic gravitational potential, which can contribute towards dynamically coupling the gas disk to the stellar and the dark matter (DM) components of the galaxy. Specifically, multiple supernovae occurring in young stellar clusters give rise to superbubbles (SB), which modify the local acceleration field and alter the energy and momentum of stars of DM particles traversing them, in broad analogy to the dynamical friction caused by a massive object. We aim to quantify how the acceleration field from SBs causes dynamical friction and contributes to the secular evolution of galaxies. In order to assess this, we construct the density modifications to the gas distribution that mimics a SB. By evaluating the acceleration field from these density modifications, we see how the momentum or angular momentum of the gas hosting the SBs changes when stars pass through the SB. Combining the effects of all the stars and SBs we, construct an empirical approximation formula for the momentum loss in homogeneous and isotropic cases. We find that the rate at which the gas disc loses its specific angular momentum via the above process is up to 4% per Gyr, which translates to under half of its original value over the lifetime of the disc. Finally, we studied how the dynamical coupling of the gas disk with the DM halo depends on assumptions on the halo kinematics (e.g. rotation) and found a ~0.3% variation in the gas disc secular evolution between different DM kinematic models.

An ingeniously designed autoencoder (PrimeNet) using simulated observations of future generation ECHO satellite mission recovers CMB B mode map, angular spectrum for multipoles $\ell \lesssim 9$ and tensor to scalar ratio $r$ {\it limited only by cosmic variance down to $r= 0.0001$ and below}. We use diverse, realistically complex and detailed foreground models. PrimeNet predicts accurate results even when data with $r=0$ are tested which were not used in training, implying robust and efficient predictive power. The work eliminates a major bottleneck of weak CMB B mode reconstruction and takes a leap forward for understanding fundamental physics of the primordial Universe.

It is generally accepted that the Moon accreted from the disk formed by an impact between the proto-Earth and impactor, but its details are highly debated. Some models suggest that a Mars-sized impactor formed a silicate melt-rich (vapor-poor) disk around Earth, whereas other models suggest that a highly energetic impact produced a silicate vapor-rich disk. Such a vapor-rich disk, however, may not be suitable for the Moon formation, because moonlets, building blocks of the Moon, of 100 m-100 km may experience strong gas drag and fall onto Earth on a short timescale, failing to grow further. This problem may be avoided if large moonlets ($\gg 100$ km) form very quickly by streaming instability, which is a process to concentrate particles enough to cause gravitational collapse and rapid formation of planetesimals or moonlets. Here, we investigate the effect of the streaming instability in the Moon-forming disk for the first time and find that this instability can quickly form $\sim 100$ km-sized moonlets. However, these moonlets are not large enough to avoid strong drag and they still fall onto Earth quickly. This suggests that the vapor-rich disks may not form the large Moon, and therefore the models that produce vapor-poor disks are supported. This result is applicable to general impact-induced moon-forming disks, supporting the previous suggestion that small planets ($<1.6 R_\oplus$) are good candidates to host large moons because their impact-induced disks would be likely vapor-poor. We find a limited role of streaming instability in a satellite formation in an impact-induced disk, whereas it plays a key role during planet formation.

Using data from the Neutron star Interior Composition ExploreR (NICER) observatory, we identified a permanent spin frequency decrease of $\Delta\nu=-(1.04\pm0.07)\times 10^{-7}\,\mathrm{Hz}$ around MJD 60132 in the rotation-powered pulsar PSR B0540-69, which exhibits a periodic signal at a frequency of $\nu\sim 19.6\,\mathrm{Hz}$. This points to an anti-glitch event, a sudden decrease of the pulsar's rotational frequency without any major alteration in the pulse profile or any significant increase of the pulsed flux. Additionally, no burst activity was observed in association with the anti-glitch. To date, observations of the few known anti-glitches have been made in magnetars or accreting pulsars. This is the first anti-glitch detected in a rotation-powered pulsar. Given its radiatively quiet nature, this anti-glitch is possibly of internal origin. Therefore, we tentatively frame this event within a proposed mechanism for anti-glitches where the partial `evaporation' of the superfluid component leads to an increase of the normal component's moment of inertia and a decrease of the superfluid one.

Context. Transient astronomical events that exhibit no discernible association with a host galaxy are commonly referred to as hostless. These rare phenomena are associated with extremely energetic events, and they can offer unique insights into the properties and evolution of stars and galaxies. However, the sheer number of transients captured by contemporary high-cadence astronomical surveys renders the manual identification of all potential hostless transients impractical. Therefore, creating a systematic identification tool is crucial for studying these elusive events. Aims. We present the ExtragaLactic alErt Pipeline for Hostless AstroNomical Transients (ELEPHANT), a framework for filtering hostless transients in astronomical data streams. Methods. We used Fink to access all the ZTF alerts produced between January/2022 and December/2023, selecting only those associated with extragalactic transients. We then processed the associated stamps using a sequence of image analysis techniques to retrieve hostless candidates. Results. We find that less than 2% of all analyzed transients are potentially hostless. Among them, approximately 10% have a spectroscopic class reported on TNS, with Type Ia supernova being the most common class, followed by SLSN. Among the hostless candidates retrieved by our pipeline, there was SN 2018ibb, which has been proposed to be a PISN candidate; and SN 2022ann, one of only five known SNe Icn. When no class is reported on TNS, the dominant classes are QSO and SN candidates, the former obtained from SIMBAD and the latter inferred using the Fink ML classifier. Conclusions. ELEPHANT represents an effective strategy to filter extragalactic events within large and complex astronomical alert streams. There are many applications for which this pipeline will be useful, ranging from transient selection for follow-up to studies of transient environments.

Eclipsing binary systems have a unique feature, which enables scientists to obtain precise fundamental star parameters, which opens to greater area of astrophysics studies. In this study, we have derived the fundamental parameters, the evolutionary status, and the birthplace of V454 Aur in the Galaxy by combining radial velocity, photometric, and spectral energy distribution data. We have updated ephemerides and period of V454 Aur as $2458850.80136_{-0.00001}^{\,+0.00001}$ and $27.0198177_{-0.0000003}^{\,+0.0000003}$, respectively. We obtain $1.173^{\,+0.016}_{-0.016}$ $M_\odot$ and $1.203^{\,+0.022}_{-0.026}$ $R_\odot$ for the primary component and $1.045^{\,+0.015}_{-0.014}$ $M_\odot$ and $0.993^{\,+0.034}_{-0.027}$ $R_\odot$ for the secondary component. The effective temperatures for the components are accurately determined via SED data as $6250^{\,+150}_{-150}$ K and $5966^{\,+109}_{-89}$ K for the primary component and the secondary component, respectively. The metallicity of the components is derived from evolutionary tracks, which implies slightly higher than Solar metallicity. According to analysis, the components of V454 Aur are on the main sequence. Our distance calculation for the system is, which is $65.07^{\,+2}_{-3}$ pc, in excellent agreement with \textit{Gaia} astrometric data, which is $65.07^{\,+0.09}_{-0.09}$ pc. The current age of the system is $1.19_{-0.09}^{\,+0.08}$ Gyr, and it will start to mass transfer between components in 5 Gyr from now on. Dynamical orbital analysis shows that V454 Aur follows a boxy pattern around the Galactic centre and is a member of the thin-disc component of the Galaxy. Considering the age and metallicity of this system, it was found to have formed just outside the Solar circle.

Quasi-stellar objects (QSOs) are a basis for an absolute reference system for astrometric studies. There is a need for creating such system behind nearby galaxies, to facilitate the measuring of the proper motions of these galaxies. However, the foreground contamination from the galaxies themselves is a problem for the QSO identification. We search for new QSOs behind both Magellanic Clouds, the Magellanic Bridge, and the Magellanic Stream. We identify QSO candidates with a combination of near-infrared colors and variability criteria from the public ESO Visual and Infrared Survey Telescope for Astronomy (VISTA) Magellanic Clouds (VMC) survey. We confirm their nature from broad emission lines with low-resolution optical spectroscopy. We confirmed the QSO nature of 136 objects. They are distributed as follows: 12 behind the LMC, 37 behind the SMC, 63 behind the Bridge, and 24 behind the Stream. The QSOs span a redshift range from z~0.1 to z~2.9. A comparison of our quasar selection with the Quaia quasar catalog, based on Gaia low-resolution spectra, yields a selection and confirmation success rate of 6-19%, depending on whether the quality of the photometry, the magnitude ranges and the colors are considered. Our candidate list is rather incomplete, but the objects in it are likely to be confirmed as quasars with ~90% probability. Finally, we report a list of 3609 objects across the entire VMC survey that match our color and variability selection criteria; only 1249 of them have Gaia counterparts. Our combined infrared color and variability criteria for QSO selection prove to be efficient - ~90% of the observed candidates are bona fide QSOs and allow to generate a list of new high-probability quasar candidates.

Neutrinos are pivotal signals in multi-messenger observations of supernovae. Recent advancements in the analysis method of supernova neutrinos, especially in quantitative analysis, have significantly broadened scientific possibilities. This study demonstrates the feasibility of estimating distances to supernovae using quantitative analysis techniques for supernova neutrinos. This estimation utilizes the direct relationship between the radius of a neutron star and the distance to the supernova. The radius of a neutron star is determined with an approximate uncertainty of 10% through observations such as X-rays and gravitational waves. By integrating this information, the distance to the supernova can be estimated with an uncertainty of within 15% at a 95% confidence level. It has been established that neutrinos can pinpoint the direction of supernovae, and when combined with distance estimates, three-dimensional localization becomes achievable. This capability is vital for follow-up observations using multi-messenger approaches. Moreover, more precise distance determinations to supernovae through follow-up observations, such as optical observations, allow for accurate measurements of neutron star radii. This data, via the neutron star mass-radius relationship, could provide various insights into nuclear physics.

The study of small ($<$300 m) near-Earth objects (NEOs) is important because they are more closely related than larger objects to the precursors of meteorites that fall on Earth. Collisions of these bodies with Earth are also more frequent. Although such collisions cannot produce massive extinction events, they can still produce significant local damage. Here we present the results of a photometric and spectroscopic survey of small NEOs, which include near-infrared (NIR) spectra of 84 objects with a mean diameter of 126 m and photometric data of 59 objects with a mean diameter of 87 m. We found that S-complex asteroids are the most abundant among the NEOs, comprising $\sim$66\% of the sample. Most asteroids in the S-complex were found to have compositions consistent with LL-chondrites. Our study revealed the existence of NEOs with spectral characteristics similar to those in the S-complex, but that could be hidden within the C- or X-complex due to their weak absorption bands. We suggest that the presence of metal or shock-darkening could be responsible for the attenuation of the absorption bands. These objects have been grouped into a new subclass within the S-complex called Sx-types. The dynamical modeling showed that 83\% of the NEOs escaped from the $\nu_{6}$ resonance, 16\% from the 3:1 and just 1\% from the 5:2 resonance. Lightcurves and rotational periods were derived from the photometric data. No clear trend between the axis ratio and the absolute magnitude or rotational period of the NEOs was found.

$ $Low density cosmic voids gravitationally lens the cosmic microwave background (CMB), leaving a negative imprint on the CMB convergence $\kappa$. This effect provides insight into the distribution of matter within voids, and can also be used to study the growth of structure. We measure this lensing imprint by cross-correlating the Planck CMB lensing convergence map with voids identified in the Dark Energy Survey Year 3 data set, covering approximately 4,200 deg$^2$ of the sky. We use two distinct void-finding algorithms: a 2D void-finder which operates on the projected galaxy density field in thin redshift shells, and a new code, Voxel, which operates on the full 3D map of galaxy positions. We employ an optimal matched filtering method for cross-correlation, using the MICE N-body simulation both to establish the template for the matched filter and to calibrate detection significances. Using the DES Y3 photometric luminous red galaxy sample, we measure $A_\kappa$, the amplitude of the observed lensing signal relative to the simulation template, obtaining $A_\kappa = 1.03 \pm 0.22$ ($4.6\sigma$ significance) for Voxel and $A_\kappa = 1.02 \pm 0.17$ ($5.9\sigma$ significance) for 2D voids, both consistent with $\Lambda$CDM expectations. We additionally invert the 2D void-finding process to identify superclusters in the projected density field, for which we measure $A_\kappa = 0.87 \pm 0.15$ ($5.9\sigma$ significance). The leading source of noise in our measurements is Planck noise, implying that future data from the Atacama Cosmology Telescope (ACT), South Pole Telescope (SPT) and CMB-S4 will increase sensitivity and allow for more precise measurements.

The decrease rate of dust mass due to strong shock waves ($v_s\geq 150$ km s$^{-1}$) from supernovae (SNe) estimated for the Milky Way interstellar medium significantly exceeds the overall production rate by both asymptotic giant branch stars and core collapse SNe. The interplay between the production and destruction rates is critically important for evaluation of the net dust outcome from SNe at different conditions. In light of this, we study the dynamics of initially polydisperse dust grains pre-existed in an ambient medium swept up the SN shock front depending on magnitude of inhomogeneity (clumpiness) in {the} medium. We find that dust destruction inside the bubble is inhibited in more inhomogeneous medium: the larger amount of dust survives for the higher dispersion of density. This trend is set by the interrelation between radiative gas cooling and dust sputtering in different environment. After several radiative times the mass fraction of the survived dust saturates at the level almost independent on the gas mean density. We note that for more clumpy medium the distributions of dust over thermal phases of a gas inside the bubble and over sizes are smoother and flatter in comparison with those in a nearly homogeneous medium.

High resolution VLBI observations revealed a quasi-stationary component (QSC) in the relativistic jets of many blazars, which represents a standing recollimation shock. The VLBA monitoring of the BL Lacertae jet at 15~GHz shows the QSC at a projected distance of about 0.26~mas from the radio core. We study the trajectory and kinematics of the QSC in BL Lacertae on sub-parsec scales using 15~GHz VLBA maps of 164 observations over 20 years from the MOJAVE program and 2~cm VLBA Survey. To reconstruct the QSC's intrinsic trajectory, we use moving average and trajectory refinement procedures to smooth out the effects of core displacement and account for QSC positioning errors. We identified 22 QSC reversal patterns on spatial scales ranging from 0.01~mas to 0.05~mas and with a frequency of $\sim 1.5$ per year. Most reversals have an acute angle $<90\degr$ at the turning point, and few have a loop-shaped or arc-shaped trajectory. The directions of reversals (clockwise or counterclockwise) appear to be random. Combinations of reversals show reversible and quasi-periodic motion. We propose a model in which the reverse motion of the QSC is due to the passage of a relativistic transverse jet wave through a fixed location of the QSC, similar to the transverse motion of a seagull on a wave. The QSC motion is governed by the amplitude, velocity, and tilt of the relativistic transverse wave. According to the model, relativistic waves are generated upstream of QSC. In the active state of the jet, the directions of the twisting waves are random, similar to the behaviour of the wave in a high-pressure hose, while in the jet stable state, the wave makes quasi-periodic oscillations with regular twisting. In this model the transverse speed of the QSC in the host galaxy frame is subluminal ($<0.3\,c$), but to an observer it appears superluminal ($\sim 2\,c$).

(abridged) Protostellar outflows exhibit large variations in their structure depending on the observed gas emission. This study analyzes the atomic jet and molecular outflow in the Class I protostar, TMC1A to characterize morphology and identify previously undetected spatial features with JWST's NIRSpec IFU. In addition to identifying a large number of Fe II and H2 lines, we have detected the bipolar Fe jet by revealing, for the first time, the presence of a red-shifted atomic jet. Similarly, the red-shifted component of the H2 slower wide-angle outflow is observed. Both Fe II and H2 red-shifted emission exhibit significantly lower flux densities compared to their blue-shifted counterparts. Additionally, we report the detection of a collimated high-velocity (100 km s-1), blue-shifted H2 outflow, suggesting the presence of a molecular jet in addition to the well-known wider angle low-velocity structure. The Fe II and H2 jets show multiple intensity peaks along the jet axis, which may be associated with ongoing or recent outburst events. In addition to the variation in their intensities, the H2 wide-angle outflow exhibits a "ring"-like structure. The blue-shifted H2 outflow also shows a left-right brightness asymmetry likely due to interactions with the surrounding ambient medium and molecular outflows. Using the Fe II line ratios, the extinction along the atomic jet is estimated to be between Av = 10-30 on the blue-shifted side, with a trend of decreasing extinction with distance from the protostar. A similar Av is found for the red-shifted side, supporting the argument for an intrinsic red-blue outflow lobe asymmetry rather than environmental effects such as extinction. This intrinsic difference revealed by the unprecedented sensitivity of JWST, suggests that younger outflows already exhibit the red-blue side asymmetry more commonly observed towards jets associated with Class II disks.

Recently Tsallis cosmology has been presented as a novel proposal for alleviating both $H_0$ and $\sigma_8$ tensions. Hence a universe filled with matter and radiation as perfect fluids and considering the Tsallis entropy is confronted using recent cosmological measurements coming from cosmic chronometers, type Ia supernovae, hydrogen II galaxies, quasars, and baryon acoustic oscillations. Following a Bayesian Markov Chain Monte Carlo analysis and combining the samples, we constrain the main characteristic parameters $\alpha = 1.031^{+0.054}_{-0.051}$ and $\delta = 1.005^{+0.001}_{-0.001}$ where the uncertainties are $1\sigma$ confidence level. Additionally, we estimate the today deceleration parameter $q_0=-0.530^{+0.018}_{-0.017}$, the deceleration-acceleration transition redshift $z_T=0.632^{+0.028}_{-0.028}$ and the age of the universe $\tau_U = 12.637^{+0.067}_{-0.066}\,\rm{Gyrs}$ which are in agreement with the standard cosmology ($\Lambda$CDM) within $1.5\sigma$. Furthermore, we find that the dark energy equation of state is consistent with both phantom and quintessence behaviors within $1\sigma$ in the past and converging to $\Lambda$CDM in the future. Finally, Tsallis cosmology is preferred over $\Lambda$CDM by the combined data, suggesting further studies at the perturbation level.

The interstellar medium (ISM) is ubiquitously turbulent across many physically distinct environments within the Galaxy. Turbulence is key in controlling the structure and dynamics of the ISM, regulating star formation, and transporting metals within the Galaxy. We present the first observational measurements of turbulence in neutral hydrogen entrained in the hot nuclear wind of the Milky Way. Using recent MeerKAT observations of two extra-planar HI clouds above (gal. lat.$\,\sim7.0^{\circ}$) and below (gal. lat.$\,\sim-3.9^{\circ}$) the Galactic disc, we analyse centroid velocity and column density maps to estimate the velocity dispersion ($\sigma_{v,\mathrm{3D}}$), the turbulent sonic Mach number ($\mathcal{M}$), the volume density dispersion ($\sigma_{\rho/\rho_0}$), and the turbulence driving parameter ($b$). We also present a new prescription for estimating the spatial temperature variations of HI in the presence of related molecular gas. We measure these turbulence quantities on the global scale of each cloud, but also spatially map their variation across the plane-of-sky extent of each cloud by using a roving kernel method. We find that the two clouds share very similar characteristics of their internal turbulence, despite their varying latitudes. Both clouds are in the sub-to-trans-sonic Mach regime, and have primarily compressively-driven ($b\sim1$) turbulence. Given that there is no known active star-formation present in these clouds, this may be indicative of the way the cloud-wind interaction injects energy into the entrained atomic material on parsec scales.

This paper presents three distinct wave trains that occurred on 2023 April 21: a broad quasi-periodic fast-propagating (QFP) wave train and a bi-directional narrow QFP wave train. The broad QFP wave train expands outward in a circular wavefront, while bi-directional narrow QFP wave trains propagate in the northward and southward directions, respectively. The concurrent presence of the wave trains offers a remarkable opportunity to investigate their respective triggering mechanisms. Measurement shows that the broad QFP wave train's speed is 300- 1100 km/s in different propagating directions. There is a significant difference in the speed of the bi-directional narrow QFP wave trains: the southward propagation achieves 1400 km/s, while the northward propagation only reaches about 550 km/s accompanied by a deceleration of about 1- 2 kms-2. Using the wavelet analysis, we find that the periodicity of the propagating wave trains in the southward and northward directions closely matches the quasi-periodic pulsations (QPPs) exhibited by the flares. Based on these results, the narrow QFP wave trains were most likely excited by the intermittent energy release in the accompanying flare. In contrast, the broad QFP wave train had a tight relationship with the erupting filament, probably attributed to the unwinding motion of the erupting filament or the leakage of the fast sausage wave train inside the filament body.

From $\sim$ 5000 deg$^{2}$ of the combination of the Beijing-Arizona Sky Survey (BASS) and Mayall $z$-band Legacy Survey (MzLS) which is also the northern sky region of the Dark Energy Spectroscopic Instrument (DESI) Legacy Imaging Surveys, we selected a sample of 31,825 candidates of low surface brightness galaxies (LSBGs) with the mean effective surface brightness 24.2 $< \bar{\mu}_{\rm eff,g} <$ 28.8 mag arcsec$^{\rm -2}$ and the half-light radius 2.5$^{\prime\prime}$ $< r_{\rm eff} <$ 20$^{\prime\prime}$ based on the released photometric catalogue and the machine learning model. The distribution of the LSBGs is of bimodality in the $g$ - $r$ color, indicating the two distinct populations of the blue ($g$ - $r <$ 0.60) and the red ($g$ - $r >$ 0.60) LSBGs. The blue LSBGs appear spiral, disk or irregular while the red LSBGs are spheroidal or ellipitcal and spatially clustered. This trend shows that the color has a strong correlation with galaxy morphology for LSBGs. In the spatial distribution, the blue LSBGs are more uniformly distributed while the red ones are highly clustered, indicating that red LSBGs preferentially populated denser environment than the blue LSBGs. Besides, both populations have consistent distribution of ellipticity (median $\epsilon\sim$ 0.3), half-light radius (median $r_{\rm eff} \sim$ 4$^{\prime\prime}$), and Sersic index (median $n$ = 1), implying the dominance of the full sample by the round and disk galaxies. This sample has definitely extended the studies of LSBGs to a regime of lower surface brightness, fainter magnitude, and broader other properties than the previously SDSS-based samples.

TOI-1338 is the first circumbinary planet system discovered by TESS. It has one transiting planet at P$\sim$95 day and an outer non-transiting planet at P$\sim$215 day complemented by RV observation. Here we present a global photo-dynamical modeling of the TOI-1338 system that self-consistently accounts for the mutual gravitational interactions between all known bodies in the system. As a result, the three-dimensional architecture of the system can be established by comparing the model with additional data from TESS Extended Mission and published HARPS/ESPRESSO radial velocity data. We report an inconsistency of binary RV signal between HARPS and ESPRESSO, which could be due to the contamination of the secondary star. According to stability analysis, the RV data via ESPRESSO is preferred. Our results are summarized as follows: (1) the inner transiting planet is extremely coplanar to the binary plane $\Delta I_b \sim 0.12 ^\circ$, making it a permanently transiting circumbinary planet at any nodal precession phases. We updated the future transit ephemerides with improved precisions. (2) The outer planet, despite its non-transiting nature, is also coplanar with the binary plane by $\Delta I_c=9.1^{+6.0 \circ}_{-4.8}$ (22$^\circ$ for 99\% upper limit). (3) The inner planet could have a density of $0.137 \pm 0.026$ g/cm$^{-3}$. With a TESS magnitude of 11.45, TOI-1338 b is an optimal circumbinary planet for ground-based follow-up and transit spectroscopy.

The Giant Magellan Telescope will use laser tomography adaptive optics to correct for atmospheric turbulence using artificial guide stars created in the sodium layer of the atmosphere (altitude ~95km). The sodium layer has appreciable thickness (~11km) and this results in the laser guide star being an elongated cylinder shape. Wavefront sensing with a Shack-Hartmann is challenging, as subapertures located further away from the laser launch position image an increasingly elongated perspective of the laser guide star. Large detectors can be used to adequately pack and sample the images on the detector, however, this increases readout noise and limits the design space available for the wavefront sensor. To tackle this challenge, we propose an original solution based on nano-engineered meta-optics tailored to produce a spatially varying anamorphic image scale compression. We present meta-lenslet array designs that can deliver ~100% of the full anamorphic image size reduction required for focal lengths down to 8mm, and greater than 50% image size reduction for focal lengths down to 2mm. This will allow greatly improved sampling of the available information across the whole wavefront sensor, while still being a viable design within the limits of current-generation fabrication facilities.

New advancements in radio data post-processing are underway within the SKA precursor community, aiming to facilitate the extraction of scientific results from survey images through a semi-automated approach. Several of these developments leverage deep learning (DL) methodologies for diverse tasks, including source detection, object or morphology classification, and anomaly detection. Despite substantial progress, the full potential of these methods often remains untapped due to challenges associated with training large supervised models, particularly in the presence of small and class-unbalanced labelled datasets. Self-supervised learning has recently established itself as a powerful methodology to deal with some of the aforementioned challenges, by directly learning a lower-dimensional representation from large samples of unlabelled data. The resulting model and data representation can then be used for data inspection and various downstream tasks if a small subset of labelled data is available. In this work, we explored contrastive learning methods to learn suitable radio data representation from unlabelled images taken from the ASKAP EMU and SARAO MeerKAT GPS surveys. We evaluated trained models and the obtained data representation over smaller labelled datasets, also taken from different radio surveys, in selected analysis tasks: source detection and classification, and search for objects with peculiar morphology. For all explored downstream tasks, we reported and discussed the benefits brought by self-supervised foundational models built on radio data.

A well-known route to form primordial black holes in the early universe relies on the existence of unusually large primordial curvature fluctuations, confined to a narrow range of wavelengths that would be too small to be constrained by Cosmic Microwave Background (CMB) anisotropies. This scenario would however boost the generation of $\mu$-type spectral distortions in the CMB due to an enhanced dissipation of acoustic waves. Previous studies of $\mu$-distortion bounds on the primordial spectrum were based on the assumptions of Gaussian primordial fluctuations. In this work, we push the calculation of $\mu$-distortions to one higher order in photon anisotropies. We discuss how to derive bounds on primordial spectrum peaks obeying non-Gaussian statistics under the assumption of local (perturbative or not) non-Gaussianity. We find that, depending on the value of the peak scale, the bounds may either remain stable or get tighter by several orders of magnitude, but only when the departure from Gaussian statistics is very strong. Our results are translated in terms of bounds on primordial supermassive black hole mass in a companion paper.

Explaining the origin of supermassive black holes via a primordial origin is severely challenged by the tight spectral distortion constraints on the amplitude of the primordial perturbations. Following the first calculation of how the $\mu$ constraints are modified by non-Gaussianity in a companion paper, we here make the first robust constraints on primordial black hole formation under large non-Gaussianity. Even the infinite $f_{\rm NL}$ limit is insufficiently non-Gaussian but much higher-order non-Gaussianity of the form ${\cal R}={\cal R}_{\rm G}^5$ may allow the formation of any mass primordial black hole without conflicting with distortion constraints. We caution that such extreme models face other challenges.

Stellar intensity interferometry (SII) is based on the correlation of the light intensity fluctuations of a star detected at two or more telescopes, with no need to combine the collected photons directly. A measurement of the correlation in full "photon-counting mode" was experimented with fast photon counters in Italy (2016-2020) and is currently being adapted to the ASTRI Mini-Array. Performing image synthesis with "photon-counting" SII requires a series of preparatory activities that involve the optimization of the pipelines for the treatment of time series acquired at extremely high photon rates, the development of efficient and innovative algorithms for the cross-correlation of the arrival times in large time series and the development of a preliminary version of a dedicated pipeline for the synthesis of images starting from interferometric data. Here we present the project and the present status of the activities.

We recently found that streaming cosmic rays (CRs) induce a resistive electric field that can accelerate secondary electrons produced by CR ionization. In this work, we study the evolution of the energy spectrum of secondary electrons by numerically solving the one-dimensional Boltzmann equation and Ohm's law. We show that the accelerated secondary electrons further ionize a gas, that is, the electron avalanche occurs, resulting in increased ionization and excitation of the gas. Although the resistive electric field becomes weaker than one before the CR discharge, the weak resistive electric field weakly accelerates the secondary electrons. The quasi-steady state is almost independent of the initial resistive electric field, but depends on the electron fraction in the gas. The resistive electric field in the quasi-steady state is larger for the higher electron fraction, which makes the number of secondary electrons that can ionize the gas larger, resulting in a higher ionization rate. The CR discharge could explain the high ionization rate that are observed in some molecular clouds.

We compile the catalog of Hvar Observatory solar observations in the time period corresponding to regular digitally stored chromospheric and photospheric observations 2010-2019. We make basic characterisation of observed phenomena and compare them to catalogs which are based on full disc solar images. We compile a catalog of observed ARs consisting of 1100 entries, where each AR is classified according to McIntosh and Mt Wilson classifications. We find that HVAR observations are biased towards more frequently observing more complex ARs and observing them in longer time periods, likely related to the small FOV not encompassing the whole solar disc. In H$\alpha$ observations we catalog conspicuous filaments/prominences and flares. We characterise filaments according to their location, chirality (if possible) and eruptive signatures. Analysis of the eruptive filaments reveals a slight bias in HVAR catalog towards observation of partial eruptions, possibly related to the observers tendency to observe filament which already showed some activity. In the flare catalog we focus on their observed eruptive signatures (loops or ribbons) and their shape. In addition, we associate them to GOES soft X-ray flares to determine their corresponding class. We find that HVAR observations seem biased towards more frequently observing stronger flares and observing them in longer time periods. We demonstrate the feasibility of the catalog on a case study of the flare detected on 2 August 2011 in HVAR H$\alpha$ observations and related Sun-to-Earth phenomena. Through flare-CME-ICME association we demonstrate the agreement of remote and in situ properties. The data used for this study, as well as the catalog, are made publicly available.

It might be necessary to access the impact of recent released Dark Energy Spectroscopic Instrument (DESI) data on the state equation of dark energy in the Hubble-tension-free cosmologies. In this paper, we report the MCMC analysis for the $w_0w_a$CDM model with pre-recombination early dark energy (EDE) using Planck+DESI+Pantheon+SH0ES dataset. The results reveal that $H_0=72.43\pm 0.75$, $w_0=-0.971\pm0.035$, $w_a=-0.347\pm0.120$ for axion-like EDE, while $H_0=73.32\pm 0.64$, $w_0=-0.923\pm0.054$, $w_a=-0.435\pm0.132$ for AdS-EDE, and also not surprisingly the spectral index of primordial scalar perturbation moves towards $n_s=1$. It looks like that in corresponding models the bestfit $H_0$ are higher than those with pre-DESI BAO data, but without the further exacerbation of $S_8$ tension.

Context. Carbon is the fourth most abundant element in the universe and its distribution is critical to understanding stellar evolution and nucleosynthesis. In optical studies of ionized nebulae, the only way to determine the C/H abundance is by using faint CII recombination lines (RLs). However, these lines give systematically higher abundances than their collisionally excited counterparts, observable at ultraviolet (UV) wavelengths. Therefore, a proper understanding of the excitation mechanisms of the faint permitted lines is crucial for addressing this long-standing abundance discrepancy (AD) problem. Aims. In this study, we investigate the excitation mechanisms of CII lines {\lambda}{\lambda}3918, 3920, 4267, 5342, 6151, 6462, 7231, 7236, 7237 and 9903. Methods. We use the DEep Spectra of Ionized REgions Database (DESIRED) that contains spectra of HII regions, planetary nebulae and other objects to analyze the fluorescence contributions to these lines and the accuracy of the atomic recombination data used to model the C+ ion. Results. We find that CII {\lambda}{\lambda}4267, 5342, 6151, 6462 and 9903 arise exclusively from recombinations with no fluorescent contributions. In addition, the recombination theory for these lines is consistent with the observations. Our findings show that the AD problem for C2+ is not due to fluorescence in the widely used CII lines or errors in their atomic parameters, but to other phenomena like temperature variations or chemical inhomogeneities. On the other hand, CII {\lambda}{\lambda}3918, 3920, 6578, 7231, 7236, 7237 have important fluorescent contributions, which are inadvisable for tracing the C2+ abundances. We also discuss the effects of possible inconsistencies in the atomic effective recombination coefficients of CII {\lambda}{\lambda}6578, 7231, 7236 and 7237.

Supernova remnants (SNRs) are likely to be significant sources of cosmic rays up to the knee of the local cosmic-ray (CR) spectrum. They produce gamma-rays in the very-high-energy (VHE) ($E>0.1$ TeV) range via: hadronic interactions with the interstellar medium and leptonic interactions with soft photons. Current observations have lead to the detection of about a dozen of VHE SNRs and future instruments should increase this number. The details of particle acceleration at SNRs, and of the mechanisms producing VHE gamma-rays at SNRs are poorly understood. We aim to study the population of SNRs detected in the TeV range and its properties, and to address fundamental questions of particle acceleration at SNR shocks: What is the spectrum of accelerated particles? What is the efficiency of acceleration? Is the VHE emission dominated by hadronic or leptonic interactions? By means of Monte Carlo methods, we simulate the population of SNRs in the VHE domain and confront our simulations to H.E.S.S. Galactic Plane Survey (HGPS). We explore the parameter space: the slope of accelerated particles $\alpha$, the electron-to-proton ratio $K_{\rm ep}$, and the efficiency of particle acceleration $\xi $. We found sets of parameters for which $\gtrsim 90$\% of realisations are found in agreements with the HGPS data. These parameters are found $ 4.2 \gtrsim \alpha \gtrsim 4.1 $, $10^{-5} \lesssim K_{\rm ep} \lesssim 10^{-4.5}$, and $0.03 \lesssim \xi\lesssim 0.1 $ . We were able to strongly argue against some regions of the parameter space: $\alpha \lesssim 4.05$, $\alpha \gtrsim 4.35$, or $K_{\rm ep} \gtrsim 10^{-3}$. Our model is so far able to explain the SNR population of the HGPS. Our approach, confronted to the results of future systematic surveys, will help remove degeneracy in the solutions, and to better understand particle acceleration at SNR shocks.

The correlation of light from two sources leads to an interference pattern if they belong to a specific time interval known as the coherence time, denoted as $\Delta \tau$. The relationship governing this phenomenon is $\Delta \tau \Delta \nu \approx 1$, where $\Delta \nu$ represents the bandwidth of the light. This requirement is not satisfied, and hence, interference fringes are not observable in the case of ordinary (thermal) light. In the 1950s, Robert Hanbury Brown and Richard Q. Twiss explored interference phenomena using a narrow bandwidth of thermal light. This investigation led to the discovery of the Hanbury-Brown and Twiss effect (or the HBT effect in short), which has since found applications in various fields, particularly stellar observations and quantum optics. This article briefly traces the history of the HBT effect and its applications in various fields, including stellar observations. More importantly, it outlines the basic theoretical framework of this effect, followed by the design and results of the correlation in intensity fluctuation of a pseudo-thermal light in a college laboratory setting (Michelson interferometer).

Major European Union-funded research infrastructure and open science projects have traditionally included dissemination work, for mostly one-way communication of the research activities. Here we present and review our radical re-envisioning of this work, by directly engaging citizen science volunteers into the research. We summarise the citizen science in the Horizon-funded projects ASTERICS (Astronomy ESFRI and Research Infrastructure Clusters) and ESCAPE (European Science Cluster of Astronomy and Particle Physics ESFRI Research Infrastructures), engaging hundreds of thousands of volunteers in providing millions of data mining classifications. Not only does this have enormously more scientific and societal impact than conventional dissemination, but it facilitates the direct research involvement of what is often arguably the most neglected stakeholder group in Horizon projects, the science-inclined public. We conclude with recommendations and opportunities for deploying crowdsourced data mining in the physical sciences, noting that the primary goal is always the fundamental research question; if public engagement is the primary goal to optimise, then other, more targeted approaches may be more effective.

The internal kinematics of the Large Magellanic Cloud (LMC) disk have been modeled by several studies using different tracers with varying coverage, resulting in a range of parameters. Here, we modeled the LMC disk using 1705 star clusters and field stars, based on a robust Markov Chain Monte Carlo (MCMC) method, using the Gaia DR3 data. The dependency of model parameters on the age, coverage, and strength of the clusters are also presented. This is the first comprehensive 2D kinematic study using star clusters. Red clump (RC) stars and young main-sequence stars are also modeled for comparison. The clusters and field stars are found to have distinctly different kinematic centers, disk inclination, position angle of the line of nodes, and scale radius. We also note a significant radial variation of the disk parameters. Clusters and young stars are found to have a large residual proper motion and a relatively large velocity dispersion when compared to the RC field population, which could be due to perturbation from the bar and spiral arms. We traced the presence of large residual proper motion and non-circular motion among clusters likely to be due to the bar and detected a decrease in the scale radius as a result of the possible evolution of the bar. The kinematically deviant clusters point to a spatio-temporal disturbance in the LMC disk, matching with the expected impact factor and time of the recent collision between the LMC and the Small Magellanic Cloud.

Nuclear reactions drive the stellar evolution and contribute to the stellar and galactic chemicals abundances. New determinations of the nuclear reaction rates for key fusion reactions of stellar evolution are now available, paving the way to improved stellar model predictions. We explore the impact of new C12+C12 reaction rates for massive stars evolution, structure, and nucleosynthesis during core carbon-burning phase. We analyse the consequences for stars of different masses including rotation-induced mixing. We computed a grid of massive stars at solar metallicity using the stellar evolution code GENEC. We explored the results using three different references for the rates, with or without rotation. We study the effect in terms of evolution, structure, and critical mass limit between intermediate and massive stars. We explored the consequences for nucleosynthesis during the core C-burning phase by means of a one-zone nucleosynthesis code. We confirm the significant impact of using the recent nuclear reaction rates following the hindrance hypothesis as well as the mass-dependent effect of a resonance at 2.14 MeV. This impacts the characteristics of the core of stars from the C-ignition and during all the core C-burning phase. The change of rates modifies the central nucleosynthesis during the core C-burning phase, resulting in an underproduction of s-process elements. The correct and accurate determination of the nuclear reaction rates, with especially the existence and location of resonances, impacts stellar evolution in many aspects affecting the model predictions. The choice of the nuclear reaction rates reference for the C12+C12 fusion reaction changes significantly the behaviour of the core during the C-burning phase. This choice is then to be taken carefully in order to interpret stellar evolution and fate of massive stars.

Predicting the properties of the matter ejected during and after a neutron star merger is crucial to our ability to use electromagnetic observations of these mergers to constrain the masses of the neutron stars, the equation of state of dense matter, and the role of neutron star mergers in the enrichment of the Universe in heavy elements. Our ability to reliably provide such predictions is however limited by a broad range of factors, including the finite resolution of numerical simulations, their treatment of magnetic fields, neutrinos, and neutrino-matter interactions, and the approximate modeling of the equation of state of dense matter. In this manuscript, we study specifically the role that a small residual eccentricity and different implementations of the same equation of state have on the matter ejected during the merger of a $1.3M_\odot-1.4M_\odot$ binary neutron star system. We find that a residual eccentricity $e\sim 0.01$, as measured $\sim 4-6$ orbits before merger, causes $O(25\%-30\%)$ changes in the amount of ejected mass, mainly due to changes in the amount of matter ejected as a result of core bounces during merger. We note that $O(1\%)$ residual eccentricities have regularly been used in binary neutron star merger simulations as proxy for circular binaries, potentially creating an additional source of error in predictions for the mass of the dynamical ejecta.

A fundamental question regarding the evolution of dwarf spheroidal galaxies is the identification of the key physical mechanisms responsible for gas depletion. Here, we focus on the study of stellar feedback in isolated dwarf spheroidal galaxies, by performing numerical simulations using a modified version of the SPH code GADGET-3. The Milky Way satellite Leo II (PGC 34176) in the Local Group was considered as our default model dwarf galaxy. The parameter space for the stellar feedback models was explored to match observational constraints of Leo II, such as residual gas mass, total mass within the tidal radius, star formation history, final stellar mass, stellar ages and metallicity. Additionally, we examined the impact of the binary fraction of stars, initial mass function, dark matter halo mass and initial gas reservoir. Many simulations revealed recent star formation quenching due to stellar feedback. In general, the gas depletion, expected star formation history, total mass of stars and total mass within the tidal radius were adequately reproduced in the simulations when compared to observational estimates. However, there were discrepancies in the distribution of stellar ages and metallicities, which suggested that the cosmic gas infall would play a more complex role in our dwarf spheroidal galaxy than captured by a monolithic infall scenario. Our results suggest that currently quenched dwarf galaxies may not necessarily need to evolve within clusters or groups, and that stellar feedback alone could be a sufficient factor in shaping at least some of these galaxies as we observe them today.

We study the merger of black hole-neutron star (BH-NS) binaries in numerical relativity, focusing on the properties of the remnant disk and the ejecta, varying the mass of compactness of the NS and the mass and spin of the BH. We find that within the precision of our numerical simulations, the remnant disk mass and ejecta mass normalized by the NS baryon mass ($\hat{M}_{\rm{rem}}$ and $\hat{M}_{\rm{eje}}$, respectively), and the cutoff frequency $f_{\rm{cut}}$ normalized by the initial total gravitational mass of the system at infinite separation approximately agree among the models with the same NS compactness $C_{\rm{NS}}=M_{\rm{NS}}/R_{\rm{NS}}$, mass ratio $Q=M_{\rm{BH}}/M_{\rm{NS}}$, and dimensionless BH spin $\chi_{\rm{BH}}$ irrespective of the NS mass $M_{\rm{NS}}$ in the range of $1.092$--$1.691\,M_\odot$. This result shows that the merger outcome depends sensitively on $Q$, $\chi_{\rm BH}$, and $C_{\rm{NS}}$ but only weekly on $M_{\rm{NS}}$. This justifies the approach of studying the dependence of NS tidal disruptions on the NS compactness by fixing the NS mass but changing the EOS. We further perform simulations with massive NSs of $M_{\rm{NS}}=1.8M_{\odot}$, and compare our results of $\hat{M}_{\rm{rem}}$ and $\hat{M}_{\rm{eje}}$ with those given by existing fitting formulas to test their robustness for more compact NSs. We find that the fitting formulas obtained in the previous studies are accurate within the numerical errors assumed, while our results also suggest that further improvement is possible by systematically performing more precise numerical simulations.

Solar pores are intense concentrations of magnetic flux that emerge through the Sun's photosphere. When compared to sunspots, they are much smaller in diameter and hence can be impacted and buffeted by neighbouring granular activity to generate significant magnetohydrodynamic (MHD) wave energy flux within their confines. However, observations of solar pores from ground-based telescope facilities may struggle to capture subtle motions synonymous with higher-order MHD wave signatures due to seeing effects produced in the Earth's atmosphere. Hence, we have exploited timely seeing-free and high-quality observations of four small magnetic pores from the Polarimetric and Helioseismic Imager (PHI) on board the Solar Orbiter spacecraft. Through acquisition of data under stable observing conditions, we have been able to measure the area fluctuations and horizontal displacements of the solar pores. Cross correlations between perturbations in intensity, area, line-of-sight velocity, and magnetic fields, coupled with the first-time application of novel Proper Orthogonal Decomposition (POD) techniques on the boundary oscillations, provide a comprehensive diagnosis of the embedded MHD waves as sausage and kink modes. Additionally, the previously elusive m = 2 fluting mode is identified in the most magnetically isolated of the four pores. An important consideration lies in how the identified wave modes contribute towards the transfer of energy into the upper solar atmosphere. We find that the four pores examined have approximately 56%, 72%, 52%, and 34% of their total wave energy associated with the identified sausage modes, and around 23%, 17%, 39%, and 49% to their kink modes, respectively, while the first pore also has around an 11% contribution linked to the fluting mode. This study marks the first-time identification of concurrent sausage, kink, and fluting MHD wave modes in solar magnetic pores.

Aims. We explore the dynamical friction on a test mass in gravitational systems in the Quasi linear formulation of Modified Newtonian Dynamics (QuMOND). Methods. Exploiting the quasi linearity of QuMOND we derive a simple expression for the dynamical friction in akin to its Newtonian counterpart in the standard Chandrasekhar derivation. Moreover, adopting a mean field approach based on the Liouville equation we obtain a more rigorous (though in integral form) dynamical friction formula that can be evaluated numerically for a given choice of the QuMOND interpolation function. Results. Consistently with previous work, we observe that dynamical friction is stronger in MOND with respect to a baryon only Newtonian system with the same mass distribution. This amounts to a correction of the Coulomb logarithmic factor via extra terms proportional to the MOND radius of the system. Moreover, with the aid of simple numerical experiments we confirm our theoretical predictions and those of previous work on MOND.

SatHub is one of the four hubs of the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS). It focuses on observations, data analysis, software, and training materials to improve our understanding of the impact of satellite constellations on astronomy and observers worldwide. As a preface to more in-depth IAUS385 sessions, we gave a summary of some recent work by SatHub members and the current status of satellite constellations, including optical and radio observations. We shared how the audience can join or get more involved, e.g., via the CPS Slack for asynchronous collaboration. We also touched on what a future with hundreds of thousands of constellation satellites might look like.

Ultrahot Jupiters are a type of gaseous exoplanet that orbit extremely close to their host star, resulting in significantly high equilibrium temperatures. In recent years, high-resolution emission spectroscopy has been broadly employed in observing the atmospheres of ultrahot Jupiters. We used the CARMENES spectrograph to observe the high-resolution spectra of the dayside hemisphere of MASCARA-1b in both visible and near-infrared. Through cross-correlation analysis, we detected signals of \ion{Fe}{i} and \ion{Ti}{i}. Based on these detections, we conducted an atmospheric retrieval and discovered the presence of a strong inversion layer in the planet's atmosphere. The retrieved Ti and Fe abundances are broadly consistent with solar abundances. In particular, we obtained a relative abundance of [Ti/Fe] as $-1.0 \pm 0.8$ under the free retrieval and $-0.4^{+0.5}_{-0.8}$ under the chemical equilibrium retrieval, suggesting the absence of significant titanium depletion on this planet. Furthermore, we considered the influence of planetary rotation on spectral line profiles. The resulting equatorial rotation speed was determined to be $4.4^{+1.6}_{-2.0}\,\mathrm{km\,s^{-1}}$, which agrees with the rotation speed induced by tidal locking.

Our previous model (NEOMOD2) for the orbital and absolute magnitude distribution of Near Earth Objects (NEOs) was calibrated on the Catalina Sky Survey observations between 2013 and 2022. Here we extend NEOMOD2 to include visible albedo information from the Wide-Field Infrared Survey Explorer. The debiased albedo distribution of NEOs can be approximated by the sum of two Rayleigh distributions with the scale parameters p_V,dark=0.03 and p_V,bright=0.17. We find evidence for smaller NEOs having (on average) higher albedos than larger NEOs; this is likely a consequence of the size-dependent sampling of different main belt sources. These inferences and the absolute magnitude distribution from NEOMOD2 are used to construct the debiased size distribution of NEOs. We estimate 830+/-60 NEOs with diameters D>1 km and 20,000+/-2,000 NEOs with D>140 m. The new model, NEOMOD3, is available via the NEOMOD Simulator -- an easy-to-operate code that can be used to generate user-defined samples (orbits, sizes and albedos) from the model.

The idea of composite dark energy (DE) is quite natural since on general grounds we expect that the vacuum energy (associated to the cosmological term $\Lambda$) may appear in combination with other effective forms of DE, collectively denoted $X$. This was indeed the old proposal from 2006, (cf. Ref.[41]) called the `$\Lambda$XCDM model', which was primordially designed to explain the cosmic coincidence problem. We now find that it can also have far reaching consequences on the current cosmological tensions on $H_0$ and the growth of large scale structure (LSS). The $\Lambda$XCDM may involve both a phantom-like component $X$ and a constant cosmological term $\Lambda$ (positive or negative) or even a running one, $\Lambda=\Lambda(H)$. In the current work, we deal with a simplified version of the model and exploit the possibility that $X$ behaves as `phantom matter' (PM). The latter appears in stringy versions of the running vacuum model (RVM). Unlike phantom DE, it satisfies the strong energy condition like usual matter, hence bringing to bear positive pressure at the expense of negative energy. Bubbles of PM may appear in the manner of a transitory `phantom vacuum' tunneled into the late universe before it heads towards a new de Sitter era, thereby offering a crop field for the growing of structures earlier than expected. Using SNIa, cosmic chronometers, transversal BAO, LSS data and the full CMB likelihood from Planck 2018, we find that the tensions virtually disappear in this stringy RVM scenario characterized by axionic dark matter. The value of $H_0$ emerging from our analysis proves compatible with SH0ES to within less than $0.25\sigma$ and the LSS growth tension is nonexistent. The statistical information criteria point to very strong evidence in favor of the PM solution.

Magnetic tornadoes, characterized as impulsive Alfven waves initiated by photospheric vortices in intergranular lanes, are considered efficient energy channels to the corona. Despite their acknowledged importance for solar coronal heating, their observational counterparts from the corona have not been well understood. To address this issue, we use a radiative MHD simulation of a coronal loop with footpoints rooted in the upper convection zone, and synthesize the chromospheric and coronal emissions corresponding to a magnetic tornado. Considering SDO/AIA 171 A and Solar Orbiter/EUI 174 A channels, our synthesis reveals that the coronal response to magnetic tornadoes can be observed as an EUV brightening of which width is ~2 Mm. This brightening is located above the synthesized chromospheric swirl observed in Ca II 8542 A, Ca II K, and Mg II k lines, which can be detected by instruments such as SST/CRISP, GST/FISS, and IRIS. Considering the height correspondence of the synthesized brightening, magnetic tornadoes can be an alternative mechanism for the small-scale EUV brightenings such as the solar "campfires''. Our findings indicate that coordinated observations encompassing the chromosphere to the corona are indispensable for comprehending the origin of coronal EUV brightenings.

Galaxies that cause the strong gravitational lensing of background galaxies provide us crucial information about the distribution of matter around them. Traditional modelling methods that analyse such strong lenses are both time and resource consuming, require sophisticated lensing codes and modelling expertise. To study the large lens population expected from imaging surveys such as LSST, we need fast and automated analysis methods. In this work, we build and train a simple convolutional neural network with an aim to rapidly predict model parameters of gravitational lenses. We focus on the most important lens mass model parameters, namely, the Einstein radius, the axis ratio and the position angle of the major axis of the mass distribution. The network is trained on a variety of simulated data with an increasing degree of realism and shows satisfactory performance on simulated test data. The trained network is then applied to the real sample of galaxy-scale candidate lenses from the Subaru HSC, a precursor survey to LSST. Unlike the simulated lenses, we do not have the ground truth for the real lenses. Therefore, we have compared our predictions with those from YattaLens, a lens modelling pipeline. Additionally, we also compare the parameter predictions for 10 HSC lenses that were also studied by other conventional modelling methods. These comparisons show a fair quantitative agreement on the Einstein radius, although the axis ratio and the position angle from the network as well as the individual modelling methods, seem to have systematic uncertainties beyond the quoted errors.

ALMA (Atacama Large Millimetre/submillimetre Array) observations of the thermal emission from protoplanetary disc dust have revealed a wealth of substructures that could evidence embedded planets, but planet-driven spirals, one of the more compelling lines of evidence, remain relatively rare. Existing works have focused on detecting these spirals using methods that operate in image space. Here, we explore the planet detection capabilities of fitting planet-driven spirals to disc observations directly in visibility space. We test our method on synthetic ALMA observations of planet-containing model discs for a range of disc/observational parameters, finding it significantly outperforms image residuals in identifying spirals in these observations and is able to identify spirals in regions of the parameter space in which no gaps are detected. These tests suggest that a visibility-space fitting approach warrants further investigation and may be able to find planet-driven spirals in observations that have not yet been found with existing approaches. We also test our method on six discs in the Taurus molecular cloud observed with ALMA at 1.33 mm, but find no evidence for planet-driven spirals. We find that the minimum planet masses necessary to drive detectable spirals range from $\approx$ 0.03 to 0.5 $M_{\text{Jup}}$ over orbital radii of 10 to 100 au, with planet masses below these thresholds potentially hiding in such disc observations. Conversely, we suggest that planets $\gtrsim$ 0.5 to 1 $M_{\text{Jup}}$ can likely be ruled out over orbital radii of $\approx$ 20 to 60 au on the grounds that we would have detected them if they were present.

We study the linear stability of regular $n$-gon rotating equilibria in the $n$-body problem with logarithm interaction. In the presence of a central mass $M$, linear stability is insured if $M$ is bounded below and above by constants depending on the number and mass of the (equal) outer $n$ bodies. Moreover, we provide explicit equations of these bounds. In the absence of a central mass we find that the regular $n$-gon is linearly stable for $n =2,3,\ldots 6$ only.

An analytic calculation is given for binary star evaporation under the tidal perturbation from randomly distributed, spatially extended dark objects. In particular, the Milky Way's wide binary star population are susceptible to such disruption from dark matter solitons of comparable and larger sizes. We identify high-probability `halo-like' wide binaries in GAIA EDR3 with separations larger than 0.1 parsec. Survival of the farthest-separated candidates will provide a novel gravitational probe to dark matter in the form of solitons. In case of dilute axion-like solitons, the observational sensitivity is shown to extend into the axion mass range $m_a \sim 10^{-17}-10^{-15}$ eV.

Mathur and Mehta won the third prize in the 2023 Gravity Research Foundation Essay Competition for proving the universality of black hole (BH) thermodynamics. Specifically, they demonstrated that any Extremely Compact Object (ECO) must have the same BH thermodynamic properties regardless of whether or not the ECO possesses an event horizon. The result is remarkable, but it was obtained under the approximation according to which the BH emission spectrum has an exactly thermal character. In fact, strong arguments based on energy conservation and BH back reaction imply that the spectrum of the Hawking radiation cannot be exactly thermal. In this work the result of Mathur and Mehta will be extended to the case where the radiation spectrum is not exactly thermal using the concept of BH dynamical state.

This paper reviews the standard algorithm for converting spacecraft state vectors to Keplerian orbital elements with a focus on its computer implementation. It analyzes the shortcomings of the scheme as described in the literature, and proposes changes to address orbits of arbitrary eccentricity and inclination in a robust way. Next, it presents two alternative schemes that simplify the program structure while improving the accuracy and speed of the transformation on modern computer architectures. Comprehensive numerical benchmarks demonstrate accuracy improvements by two orders of magnitude, together with a 40% reduction of computational cost relative to the standard implementation.

Ultralight electrophilic scalar field can mediate a long-range force or radiate from a pulsar or a magnetar if the scalar field has a coupling with the Goldreich-Julian charge density or the net electron charge density of the star. The interaction of the electron with the long-range scalar profile results in a spatial variation of the electron mass. A scalar induced magnetic field is created due to such interaction. The mass of the scalar in such cases is constrained by the radius of the star. The scalar field can also radiate from a binary system or an isolated star if the mass of the scalar is less than the orbital frequency and the spin frequency respectively. The electrophilic scalar radiation can contribute to the orbital period loss of binary systems and pulsar spin-down. Comparing with existing and projected experimental sensitivities, we obtain constraints on scalar coupling with ultralight mass. Some of these bounds are stronger than the existing fifth force constraints. The constraints on the scalar coupling can be significantly screened if the scalar has a coupling with the ubiquitous cosmic neutrino background. Improvements in experimental sensitivity and observations of compact objects with stronger magnetic fields and higher angular velocities could further refine these bounds.

We present a flow-based method for simulating and calculating nucleation rates of first-order phase transitions in scalar field theory on a lattice. Motivated by recent advancements in machine learning tools, particularly normalizing flows for lattice field theory, we propose the ``partitioning flow-based Markov chain Monte Carlo (PFMCMC) sampling" method to address two challenges encountered in normalizing flow applications for lattice field theory: the ``mode-collapse" and ``rare-event sampling" problems. Using a (2+1)-dimensional real scalar model as an example, we demonstrate the effectiveness of our PFMCMC method in modeling highly hierarchical order parameter probability distributions and simulating critical bubble configurations. These simulations are then used to facilitate the calculation of nucleation rates. We anticipate the application of this method to (3+1)-dimensional theories for studying realistic cosmological phase transitions.

As the number of Anthropogenic Space Objects (ASOs) grows, there is an urgent need to ensure space safety, security, and sustainability (S3) for long-term space use. Currently, no globally effective method can quantify the safety, security, and Sustainability of all ASOs in orbit. Existing methods such as the Space Sustainability Rating (SSR) rely on volunteering private information to provide sustainability ratings. However, the need for such sensitive data might prove to be a barrier to adoption for space entities. For effective comparison of ASOs, the rating mechanism should apply to all ASOs, even retroactively, so that the sustainability of a single ASO can be assessed holistically. Lastly, geopolitical boundaries and alignments play a crucial and limiting role in a volunteered rating system, limiting the space safety, security, and sustainability. This work presents a Live Detectability, Identifiability, and Trackability (L-DIT) score through a distributed app (dApp) built on top of the Behavioral Dynamics blockchain (BDB). The BDB chain is a space situational awareness (SSA) chain that provides verified and cross-checked ASO data from multiple sources. This unique combination of consensus-based information from BDB and permissionless access to data allows the DIT scoring method presented here to be applied to all ASOs. While the underlying BDB chain collects, filters, and validates SSA data from various open (and closed if available) sources, the L-DIT dApp consumes the data from the chain to provide L-DIT score that can contribute towards an operator's, manufacturer's, or owner's sustainability practices. Our dApp provides data for all ASOs, allowing their sustainability score to be compared against other ASOs, regardless of geopolitical alignments, providing business value to entities such as space insurance providers and enabling compliance validation and enforcement.

We formulate the convenient and mimetic $f(Q)$ gravities in terms of the metric and four scalar fields with the $Q$ being the non-metricity scalar. As a result, it is shown that the obtained field equations are well-defined. By using the field equations, we show how the $f(Q)$ models which realise any given FLRW spacetime may be reconstructed. We construct convenient $f(Q)$ gravity and mimetic $f(Q)$ gravity, which describe the inflation and dark energy epochs and even unify the inflation and dark energy. Moreover, a radiation-dominated epoch and early dark energy may be easily included in the above theories as is explicitly shown. It is shown that the inflationary spectral index $n_s$ and the tensor-to-scalar ratio $r$ are consistent with Planck data for some models of $f(Q)$ gravity. Corresponding asymptotic forms of $f(Q)$ and mimetic $f(Q)$ are given. Finally, some remarks on possible reconstruction for spherically symmetric spacetime are given.

The advents of Artificial Intelligence (AI)-driven models marks a paradigm shift in risk management strategies for meteorological hazards. This study specifically employs tropical cyclones (TCs) as a focal example. We engineer a perturbation-based method to produce ensemble forecasts using the advanced Pangu AI weather model. Unlike traditional approaches that often generate fewer than 20 scenarios from Weather Research and Forecasting (WRF) simulations for one event, our method facilitates the rapid nature of AI-driven model to create thousands of scenarios. We offer open-source access to our model and evaluate its effectiveness through retrospective case studies of significant TC events: Hurricane Irma (2017), Typhoon Mangkhut (2018), and TC Debbie (2017), affecting regions across North America, East Asia, and Australia. Our findings indicate that the AI-generated ensemble forecasts align closely with the European Centre for Medium-Range Weather Forecasts (ECMWF) ensemble predictions up to seven days prior to landfall. This approach could substantially enhance the effectiveness of weather forecast-driven risk analysis and management, providing unprecedented operational speed, user-friendliness, and global applicability.

A popular science article designed to introduce people familiar with basic cosmological nomenclature with models alternative to cosmological inflation. The paper briefly discusses the modern view of the Big Bang model, inflation (both its advantages and potential deficiencies). This is followed by a discussion of historical alternative models and modern approaches such as matter bounce, ekpyrotic Universe, Conformal Cyclic Cosmology, Hartle-Hawking state and loop quantum cosmology. The final aspect of the paper is to present the advantages and potential problems associated with alternative models and to present the conceptual challenges associated with the uniqueness of cosmology as a specific domain of physics.

Recent analysis of quantum cosmology has focused on the Lorentzian path integral formulations of both the no-boundary and tunneling proposals. However, it has been criticized that the wave function for linearized perturbations around a homogeneous and isotropic background leads to an inverse Gaussian distribution. This results in divergent correlation functions and cosmological inconsistencies. In this paper we explore these perturbation problems in Lorentzian quantum cosmology, focusing in particular on the quantum creation of closed, flat, and open universes from no spacetime and the beginning of primordial inflation. We show that most quantum cosmological scenarios have serious perturbation problems. We also study the effects of trans-Planckian physics on quantum cosmology, using the generalized Corley-Jacobson dispersion as a case study of modified dispersion relations. Our findings indicate that resolving perturbation problems in Lorentzian quantum cosmology with modified dispersion relations remains a challenge. However, the perturbations can be Gaussian in the quantum creation of the flat or open universe within the confines of the saddle-point approximation and the generalized Corley-Jacobson dispersion.