Papers for Monday, Nov 10 2025

We present SGNL, a scalable, low-latency gravitational-wave search pipeline. It reimplements the core matched-filtering principles of the GstLAL pipeline within a modernized framework. The Streaming Graph Navigator library, a lightweight Python streaming framework, replaces GstLAL's GStreamer infrastructure, simplifying pipeline construction and enabling flexible, modular graph design. The filtering core is reimplemented in PyTorch, allowing SGNL to leverage GPU acceleration for improved computational scalability. We describe the pipeline architecture and introduce a novel implementation of the Low-Latency Online Inspiral Detection algorithm in which components are pre-synchronized to reduce latency. Results from a 40-day Mock Data Challenge show that SGNL's event recovery and sensitivity are consistent with GstLAL's within statistical and systematic uncertainties. Notably, SGNL achieves a median latency of 5.4 seconds, a 42\% reduction compared to GstLAL's 9.3 seconds.

We present a joint cosmological analysis combining data from the Planck satellite, the Atacama Cosmology Telescope, and the South Pole Telescope, constructing a unified likelihood that reproduces the measured temperature and polarisation power spectra by jointly modelling the cosmic microwave background (CMB) signal, galactic and extragalactic foregrounds, and instrumental systematics across all datasets. This approach reduces reliance on external priors and improves the robustness of parameter estimation. Within this joint analysis, $\Lambda$CDM parameters exhibit remarkable stability with respect to variations in foreground modelling. Extended cosmological parameters are more sensitive to these assumptions, with uncertainties increasing by up to 35%. Despite this, the combined constraints show no significant deviation from $\Lambda$CDM expectations, and several previously reported tensions -- such as the preference for non-zero curvature or the excess of lensing amplitude A_L -- are significantly reduced or resolved. In contrast, the determination of foreground parameters more severely depends on the assumptions made about the underlying models. Overall, this work demonstrates the feasibility and reliability of a fully joint analysis of current CMB experiments, and emphasizes the importance of consistent and accurate foreground modelling for the scientific goals of next-generation, high-sensitivity CMB surveys.

We study the cosmology of axions in the post-inflationary scenario, where random initial conditions and the ensuing string-domain-wall network generate an isocurvature power spectrum. Axions radiated from strings behave as warm, wave-like dark matter: when they constitute the full dark matter abundance, free streaming sets the strongest bounds on their mass. For subdominant fractions, despite being warm, they still lead to an overall enhancement of structure growth in the dominant component, seeded by the axion white-noise fluctuations. We search for this effect using the ultraviolet luminosity function (UVLF) of galaxies at $z=4$-$10$, probing $k\simeq0.5$-$10\,\mathrm{Mpc}^{-1}$. Combining the UVLF analysis with Lyman-$\alpha$ and CMB data yields the leading cosmological limits on post-inflationary axion dark matter, sensitive to tiny fractions for $m_a\lesssim10^{-21}\,\mathrm{eV}$. As a byproduct, we obtain new constraints on generic white-noise power spectra from the UVLF. These results apply broadly to scenarios that generate similar isocurvature perturbations, linking early-universe field dynamics to high-redshift structure formation.

The supermassive black holes (SMBHs) with mass $M_\bullet > 10^9 \, \rm M_\odot$ hosted by high-redshift galaxies have challenged our understanding of black hole formation and growth, as several pathways have emerged attempting to explain their existence. The "heavy-seed" pathway eases the problem with the progenitors of these SMBHs having birth masses up to ${\sim} 10^5~{\rm M_\odot}$. Here, we investigate the possibility that a local dwarf galaxy, Leo I, harbors a heavy-seed descendant. Using Monte-Carlo merger trees to generate the merger histories of 1,000 dark matter halos similar to the Milky Way (MW; with a mass of ${\sim} 10^{12}~{\rm M_\odot}$ at redshift $z{=}0$). We search for Leo-like satellite halos among these merger trees, and investigate the probability that the progenitors of some of these satellites formed a heavy seed. We derive the likelihood of such "heavy seed survivors" (HSSs) across various formation and survival criteria as well as Leo-similarity criteria. We find that the virial temperature for the onset of atomic cooling and rapid gas infall that yields heavy seeds, $T_{\rm act}$, has the largest impact on the number of HSSs. We find HSSs in a fraction $0.7\%$, $18.1\%$, and $96.5\%$ of MW-like halos when $T_{\rm act}$ is set to $9,000$K, $7,000$K, and $5,000$K respectively. This suggests that Leo I could be hosting a heavy seed and could provide an opportunity to disentangle heavy seeds from other SMBH formation mechanisms.

SRGt 062340.2-265751, a cataclysmic variable identified by SRG/eROSITA due to its significant X-ray variability, remains poorly characterised despite multi-wavelength follow-up. We present spectral and timing analyses from the first dedicated X-ray and ultraviolet observations with XMM-Newton, complemented by SRG/eROSITA data from four all-sky surveys (eRASS1-4) and ASAS-SN optical photometry. Our timing analysis reveals a >8$\sigma$-significant modulation at 3.6 $\pm$ 0.5 hours, likely representing the orbital period. Long-term ASAS-SN monitoring confirms the source as a VY Sculptoris-type nova-like system, while short-timescale X-ray and ultraviolet variability, down to a few minutes, suggests a possible underlying magnetic white dwarf. Two additional significant X-ray modulations at 43 $\pm$ 1 min and 36.0 $\pm$ 0.7 min tentatively point to the spin period of an intermediate polar. The best-fit XMM-Newton energy spectra reveal a multi-temperature thermal plasma ($kT$ = 0.23, 0.94, and 5.2 keV), while the SRG/eROSITA spectra are consistent with a single-temperature thermal plasma of a few keV. We estimate unabsorbed X-ray luminosities of $\gtrsim$$10^{32}$ erg s$^{-1}$ (0.2-12 keV). Broadband spectral energy distribution modelling, from near-ultraviolet to infrared, indicates a disc-dominated system consistent with a nova-like classification. We discuss these results in the context of the source's confirmed nova-like classification and its possible magnetic nature, a scenario increasingly supported by discoveries of intermediate polars exhibiting VY Sculptoris-type nova-like features.

NASA's Artemis Mission aims to return astronauts to the Moon and establish a base at the lunar south pole. A key challenge is understanding the threat from micrometeoroid impacts, which are too small to monitor directly. Using NASA's Meteoroid Engineering Model 3 (\texttt{MEM~3}), we estimate micrometeoroid impact rates on a base comparable in size to the International Space Station (100\,m $\times$ 100\,m $\times$ 10\,m). We find that a lunar base would experience $\sim$15,000--23,000 incident impacts per year by micrometeoroids with a mass range of $10^{-6}$--$10^{1}$~g, depending on location -- with minima at the lunar poles, a maximum near the sub-Earth longitude, and a factor of $\sim$1.6 variation between the two. To assess the mitigating effect of protection systems, we present a functional relationship describing the number of impacts that penetrate the shielding as a function of the minimum meteoroid mass capable of penetrating the shield -- the ``critical mass.'' We estimate that state-of-the-art Whipple shields protect against $\sim$99.9997\% of micrometeoroids. By re-running \texttt{MEM~3} with a minimum mass equal to the critical mass of modern Whipple shields, we determine that a shielded lunar base would experience $\sim$0.024--0.037 penetrating impacts per year -- again with minima at the poles and a maximum near the sub-Earth longitude. These results indicate that (1) the lunar poles are optimal for sustained habitation, (2) gravitational focusing by Earth dominates over its geometric shielding for this micrometeoroid flux, and (3) current shielding technology can reduce micrometeoroid threats by nearly five orders of magnitude, making long-duration lunar habitation feasible.

We aim to measure the evolution of individual galaxies around the Star Formation Main Sequence (SFMS) during the last Gyr as a function of their stellar mass to quantify how much of its scatter is due to short-term this http URL derived star formation histories using full spectral fitting for a sample of 8,960 galaxies from the MaNGA survey to track the position of the galaxies in the SFMS during the last this http URL variability correlates with both the stellar mass of the galaxies and their current position in both the SFMS and the mass-metallicity relation (MZR), with the position in the latter strongly affecting variability in SFR. While most of the fluctuations are compatible with stochasticity, there is a very weak but statistically significant preference for $\sim135-150$ Myr time-scales. These results support a strong self-regulation of SFR within galaxies, establishing characteristic intensities and time-scales for bursts of star formation and quenching episodes. We also find that short-term variability cannot account for the entirety of the scatter in the SFMS. It appears to originate to a similar degree in short-term variability and long-term (halo-level) differentiation and fits predictions from models.

Astrometric perturbations of lensed arcs behind galaxy clusters have been recently suggested as promising probes of small-scale ($\lesssim10^9 M_{\odot}$) dark matter substructure. Populations of cold dark matter (CDM) subhalos, predicted in hierarchical structure formation theory, can break the symmetry of arcs near the critical curve, leading to positional shifts in the observed images. We present a novel statistical method to constrain the average subhalo mass fraction ($f_{\rm sub}$) in clusters that takes advantage of this induced positional asymmetry. Focusing on CDM, we extend a recent semi-analytic model of subhalo tidal evolution to accurately simulate realistic subhalos within a cluster-scale host. We simulate the asymmetry of lensed arcs from these subhalo populations using Approximate Bayesian Computation. Using mock data, we demonstrate that our method can reliably recover the simulated $f_{\rm sub}$ to within 68\% CI in 73\% of cases, regardless of the lens model, astrometric precision, and image morphology. We show that the constraining power of our method is optimized for larger samples of well observed arcs, ideal for recent JWST observations of cluster lenses. As a preliminary test, we apply our method to the MACSJ0416 Warhol arc and AS1063 System 1. For Warhol we constrain the upper limit on $\log f_{\rm sub} < -3.40^{+1.06}_{-0.97}$, while for AS1063 System 1 we constrain $\log f_{\rm sub} = -2.36^{+0.56}_{-0.89}$ (both at 68\% CI), consistent with CDM predictions. We elaborate on our method's limitations and its future potential to place stringent constraints on dark matter properties in cluster environments.

Hydrogenated amorphous carbon materials, a-C(:H), are heterogeneous structures consisting of carbon atoms in different hybridisation states and bonding configurations and are thought to constitute a significant and observationally important fraction of the interstellar dust material. This work aims to characterise semi-conducting a-C(:H) nanoparticle structures and, in particular, their property-characterising aromatic domain size distribution and so predict how they will behave in intense UV radiation fields that can fragment them through dissociative and charge effects as a result of carbon-carbon bond-breaking. Using a statistical approach we determine the typical sizes of the aromatic domains, their size distribution, how they are network-bonded, and where they are to be found within the structure. We consider the effects of thermal excitation, photo-dissociation and charging of a-C(:H) nanoparticles, and the products of their fragmentation. The derived UV photon-induced fragmentation lifetimes for nanometre-sized a-C(:H) nanoparticles, with radii ~0.4-0.5nm radius and containing ~40-60 carbon atoms, are of the order of 10^6-10^7yr in the diffuse interstellar medium and likely 10^2-10^4 times shorter in photodissociation regions, depending on the local radiation field intensity. Grains larger than this are stable against photodissociation. In H{\footnotesize II} regions only a-C(:H) nanoparticles with radii greater than 0.7nm (> 150 carbon atoms) are likely to survive. The photon-driven fragmentation of sub-nanometre a-C(:H) particles was determined to be important in the diffuse interstellar medium and also in high excitation regions, such as photodissociation and HII regions. However, in these same regions Coulomb fragmentation is unlikely to be an important dust destruction process.

We present a hybridized unsupervised clustering algorithm Hisaxy as a novel way to identify frequently occurring magnetic structures embedded in the interplanetary magnetic field (IMF) carried by the solar wind. The Hisaxy algorithm utilizes a combination of indexable Symbolic Aggregate approXimation (iSAX) and Hierarchical Density-Based Spatial Clustering of Applications with Noise (HDBSCAN) to efficiently identify clusters of patterns embedded in time series data. We utilized Hisaxy to identify small-scale structures, known as discontinuities, embedded in time series measurements of the IMF. In doing so, we demonstrate the capability of the algorithm to significantly reduce the amount of human analysis hours required to identify these structures, all the while maintaining a high degree of self similarity within a given cluster of time series data.

Quiescent solar prominences show distinct small-scale dynamics in observations. Their internal density contrasts with the surrounding corona make them susceptible to Rayleigh-Taylor (RT) instabilities, leading to vertically structured prominence morphologies when observed at the solar limb. As a result, prominences develop bubbles and plumes, along with secondary Kelvin-Helmholtz (KH) roll-ups along their edges. Recent observations also suggest magnetic reconnection events within the RT-driven turbulent flows. We perform high-resolution 2.5D resistive magnetohydrodynamic simulations using the open-source MPI-AMRVAC code, reaching a spatial resolution of $\sim 11.7$ km in a 2D domain of size 30 Mm$\times$30 Mm and evolving the system for approximately 10 minutes of solar time. A dense, magnetic pressure supported prominence serves as the initial state, which becomes unstable at the prominence-corona interface. The resulting interaction between RT and KH instabilities leads to the formation of current sheets and localized reconnection events. The reconnection-driven outflows form energetic jets that enhance energy transport and dissipation across the prominence. We analyze our high-resolution prominence simulation using synthetic images of the broadband SDO/AIA 094, 171, and 193 Å and narrowband H$\alpha$ filters, to compare the developing fine-scale structures with their observational counterparts. Most secondary instabilities emerge in the hotter coronal regions surrounding the cooler prominence core. While our simulated features match observed scales, speeds, and duration, the simulated activity remains concentrated in hot, surrounding coronal plasma rather then the cool prominence material, implying that key physical ingredients may be missing. Future 3D studies in more realistic magnetic configurations are required to address these limitations.

Upcoming measurements of the kinetic Sunyaev-Zel'dovich (kSZ) effect, which results from Cosmic Microwave Background (CMB) photons scattering off moving electrons, offer a powerful probe of the Epoch of Reionization (EoR). The kSZ signal contains key information about the timing, duration, and spatial structure of the EoR. A precise measurement of the CMB optical depth $\tau$, a key parameter that characterizes the universe's integrated electron density, would significantly constrain models of early structure formation. However, the weak kSZ signal is difficult to extract from CMB observations due to significant contamination from astrophysical foregrounds. We present a machine learning approach to extract $\tau$ from simulated kSZ maps. We train advanced machine learning models, including swin transformers, on high-resolution seminumeric simulations of the kSZ signal. To robustly quantify prediction uncertainties of $\tau$, we employ the Laplace Approximation (LA). This approach provides an efficient and principled Gaussian approximation to the posterior distribution over the model's weights, allowing for reliable error estimation. We investigate and compare two distinct application modes: a post-hoc LA applied to a pre-trained model, and an online LA where model weights and hyperparameters are optimized jointly by maximizing the marginal likelihood. This approach provides a framework for robustly constraining $\tau$ and its associated uncertainty, which can enhance the analysis of upcoming CMB surveys like the Simons Observatory and CMB-S4.

We present the results of our ALMA observations of the dense molecular HCN J=4-3 and HCO$^{+}$ J=4-3 lines at $\lesssim$1 pc ($\lesssim$14 mas) resolution in the nuclear region of the nearby ($\sim$14 Mpc) well-studied AGN NGC 1068. Both emission lines are clearly detected around the AGN along an almost east-west direction, which we ascribe to the dusty molecular torus. The HCN J=4-3 emission is brighter than the HCO$^{+}$ J=4-3 emission in the compact ($\lesssim$3-5 pc) torus region. Apparent counter-rotation between the inner ($\lesssim$2 pc) and outer ($\gtrsim$2 pc) parts of the western torus, previously seen in $\sim$1.5 pc-resolution HCN J=3-2 and HCO$^{+}$ J=3-2 data, is also confirmed in our new $\lesssim$1 pc-resolution HCN J=4-3 and HCO$^{+}$ J=4-3 data. We apply a physically counter-rotating torus model, in which a compact dense gas clump collided with the western side of the existing rotating torus from the opposite direction, and we find that this model largely reproduces the observed properties of the combined new $\lesssim$1 pc-resolution HCN J=4-3 and HCO$^{+}$ J=4-3 data, and the previously obtained $\lesssim$1.5 pc-resolution HCN J=3-2 and HCO$^{+}$ J=3-2 data.

Determining the structure of the Milky Way is essential for understanding its morphology, dynamics, and evolution. However, studying its innermost regions is challenging due to high extinction and crowding. The detection of a double red clump (RC; core-helium-burning stars) feature at very low Galactic latitudes suggests the presence of a spiral arm beyond the Galactic bar, providing new insights into the Galaxy's structure along this complex line of sight. We evaluate this possibility by analysing the proper motion and extinction distributions of the detected RC features. We constructed proper motion and extinction difference maps to investigate the kinematic and reddening properties of the RC populations, and the kinematic differences were validated using N-body simulations of a Milky Way-like galaxy. We find that the two RC features are kinematically distinct, with a relative proper motion difference of $-0.16\pm0.02\, mas/yr$ in the component parallel to the Galactic plane. This difference can be explained by Galactic rotation if the two RCs lie at different distances, consistent with the simulations. The extinction towards the secondary RC is also $\sim0.05$ mag higher than that of the primary RC. Additionally, we estimate that the extinction difference between the RC features corresponds to only $\sim5\%$ of the total extinction from Earth to the first RC, suggesting little interstellar material between the farthest edge of the Galactic bar and the kinematically distinct structure traced by the secondary RC. Using $JK_s$ photometry, we derive $A_J/A_{K_s}=3.34\pm0.07$, consistent with previous results and showing no significant variation across fields or along the line of sight. The results support the secondary clump tracing a distant structure, possibly a spiral arm, although we cannot exclude that the population belongs to the disc.

We use the TNG50 cosmological simulation and three-dimensional radiative transfer post-processing to generate dust-aware synthetic observations of galaxies at $ 3 \leq z \leq 6 $ and $ \log_{10}(M_\ast/\mathrm{M}_\odot) \geq 8.5 $, tailored to match the depth and resolution of current deep JWST surveys (NGDEEP and JADES). We analyse the performance of spectral energy distribution (SED) fitting on the simulated sample, focusing on the recovery of photometric redshift and stellar mass. At $ z \leq 5 $, we find that 90 per cent of redshifts are recovered within $ \pm0.2 $, but performance declines at $ z = 6 $. Stellar masses are generally well-recovered within a factor of 2, but are systematically underestimated regardless of redshift, a trend that is more pronounced at the high-mass end $ ( \log_{10}(M_\ast/\mathrm{M}_\odot) \geq 10 ) $. In addition, we study the observer-frame colours of galaxies in this redshift range as well as the SED-inferred $UVJ$ diagram. We find that TNG50 galaxies broadly follow the tendencies marked by observations, but tend to be slightly redder at lower masses and bluer at higher masses, regardless of redshift. Finally, using a colour-based definition of quiescence, we determine the fraction of quiescent galaxies as a function of stellar mass at $ 3 \leq z \leq 6 $, which we find to be broadly consistent with observations.

Gravitational waves (GWs) serve as standard sirens by directly encoding the luminosity distance to their source. When the host galaxy redshift is known, for example, through observation of an electromagnetic (EM) counterpart, GW detections can provide an independent measurement of the Hubble constant, $H_0$. However, even in the absence of an EM counterpart, inferring $H_0$ is possible through the dark siren method. In this approach, every galaxy in the GW localization volume is considered a potential host that contributes to a measurement of $H_0$, with redshift information supplied by galaxy catalogs. Using mock galaxy catalogs, we explore the effect of catalog incompleteness on dark siren measurements of $H_0$. We find that in the case of well-localized GW events, if GW hosts are found in all galaxies with host halo masses $M_h > 2 \times10^{11} M_{\odot}h^{-1}$, catalogs only need to be complete down to the 1% brightest magnitude $M_i < -22.43$ to draw an unbiased, informative posterior on H0. We demonstrate that this is a direct result of the clustering of fainter galaxies around brighter and more massive galaxies. For a mock galaxy catalog without clustering, or for GW localization volumes that are too large, using only the brightest galaxies results in a biased $H_0$ posterior. These results are important for informing future dark siren analyses with LIGO-Virgo-KAGRA as well as next-generation detectors.

For Galactic novae, I calculate and collect a comprehensive catalog of 208 measures of white dwarf (WD) masses ($M_{\rm WD}$) and 232 measures of average $V$ magnitudes in quiescence ($V_q$). These are collected into a comprehensive catalog of most fundamental properties of all 402 known Galactic novae. The nova light curve and spectral classes are determined primarily by $M_{\rm WD}$. With an apparently clean cutoff, nova with light curve shapes in the S, P, O, and C classes have $>$0.95 $M_{\odot}$, while the J, D, and F class novae have $<$0.95 $M_{\odot}$. The speed class of the light curves is $t_3$=$10^{(-1.73M_{\rm WD})}$$\times$1900 days. The spectral class of novae is Fe II below 1.15 $M_{\odot}$, is He/N above 1.15 $M_{\odot}$, and the Hybrid novae are spread around this division. Neon novae have WD masses ranging from 0.53--1.37 $M_{\odot}$, with 76\% being measured to be below their minimum formation mass of 1.2 $M_{\odot}$, demonstrating that most are losing mass over each eruption cycle. The FWHM velocity of the Balmer line profiles is close to 0.23 times the WD escape velocity, or roughly $10^{(M_{\rm WD}/2)}$$\times$500 km s$^{-1}$ for $<$1.3 $M_{\odot}$. And all the known Galactic recurrent novae are $>$1.2 $M_{\odot}$. For issues involving the late expansion of the ejecta, I find that the visibility of shells is strongly biased towards novae with orbital periods $<$0.33 days, and that the visibility of $\gamma$-rays from the shells are strongly biased towards novae with fast declines, with $t_3$ a proxy for the $\gamma$-ray luminosity.

Score-based models can serve as expressive, data-driven priors for scientific inverse problems. In strong gravitational lensing, they enable posterior inference of a background galaxy from its distorted, multiply-imaged observation. Previous work, however, assumes that the lens mass distribution (and thus the forward operator) is known. We relax this assumption by jointly inferring the source and a parametric lens-mass profile, using a sampler based on GibbsDDRM but operating in continuous time. The resulting reconstructions yield residuals consistent with the observational noise, and the marginal posteriors of the lens parameters recover true values without systematic bias. To our knowledge, this is the first successful demonstration of joint source-and-lens inference with a score-based prior.

Solar proton events (SPEs) pose radiation hazards, disrupt technology, and impact operations on Earth and in space, making continuous monitoring essential. We compare 10-50 MeV proton flux measurements from SOHO/EPHIN at Lagrange Point 1 (L1) with those from NOAA/GOES in geostationary orbit (GEO) during Solar Cycle 23 and most of Cycle 24. We identify 83 >=10 pfu SPEs observed at both locations and classify them into S1-S4 categories (comparable to NOAA's solar radiation storm scales). EPHIN detected earlier onsets and longer durations across all categories, along with earlier peaks and ends for S1-S3, while GOES recorded slightly earlier peak and end times for S4. S1 median timing offsets (EPHIN relative to GOES) were -20 +/- 50 min (onsets), -1.00 +/- 1.42 hr (peaks), and -1.08 +/- 2.21 hr (ends), with similar trends for S2-S3 and near-simultaneity for S4 (peaks ~ -0.17 +/- 1.62 hr; ends ~ +0.04 +/- 3.33 hr). Flux comparisons show that EPHIN measurements modestly exceed GOES for S1 (median ratios ~1.11 for peaks and ~1.06 for fluence) and are lower than GOES for stronger events (peaks ~0.97 +/- 0.29, 0.84 +/- 0.21; fluence ~0.84 +/- 0.16, 0.75 +/- 0.16 for S2-S3). The EPHIN-to-GOES peak flux and fluence ratios reach 0.16 +/- 0.03 and 0.29 +/- 0.07, respectively, for S4 events, originating from contamination of lower-energy GOES channels. Correlation analyses show no significant flux dependence on geomagnetic indices, field strength, or spacecraft position, suggesting minimal near-Earth modulation of >=10 MeV proton access at GEO. These results highlight systematic differences in how SPEs manifest at L1 versus GEO and offer practical guidance for forecasting beyond Earth's magnetosphere, supporting mission planning for near-Earth and cislunar exploration, including Artemis.

The Fermi Large Area Telescope has enabled detailed studies of high-energy astrophysical sources. To support analysis, we present FermiPhased, a flexible, open-source tool for phase-resolved studies of pulsars, binaries, and other periodically variable sources. Built on the Fermipy framework, FermiPhased offers three modes: standard, adaptive (fixed counts), and joint phase-resolved analysis, enabling users to flexibly bin data based on phase, count statistics, or jointly fit different epochs of interest. FermiPhased is optimized for parallel execution and use on computing clusters. It enables parallelized extraction of phase-resolved fluxes, spectra, and intermediary data products, with tutorials and documentation available on GitHub.

Positioned at geostationary orbit (GEO) ~36,000 km above Earth, NOAA's GOES series has recorded real-time energetic proton flux measurements crucial for space weather monitoring for over three decades. Although machine learning models have advanced solar energetic particle (SEP) event prediction using GOES data, the sudden yet sparse nature of SEP events necessitates high-quality proton flux measurements. Previous studies have identified contamination issues in GOES data, when the presence of higher-energy protons can cause parasitic signals in lower-energy GOES channels and lead to artificially elevated fluxes in lower energy ranges (e.g., 10 - 50 MeV). As of now, no universal correction method has been implemented for the publicly available NOAA data. In addition, the effects of Earth's magnetosphere on the 10 - 50 MeV particles are not fully understood yet. This study assesses a reconstruction method using concurrent solar proton event (SPE) measurements from SOHO-EPHIN, which align well with GOES measurements of SPEs across solar cycles 23 and the bulk of cycle 24, but represent the off-magnetospheric environment of the Lagrange 1 point. We train regression models on GOES proton fluxes across multiple energy bins, employing EPHIN fluxes as prediction targets. We expect that similar approaches can allow us to derive non-contaminated flux proxies that preserve valuable data and more accurately capture the characteristics of SPEs, providing a more stable dataset for analyzing SEP behavior and potentially improving SEP event prediction models.

Access to precise empirical estimates of stellar radii in recent decades has revealed that the radii of certain low-mass stars are inflated relative to stellar structure predictions. The largest inflations are found in magnetically active stars. Although various attempts have been made to incorporate magnetic effects into stellar structure codes, a major source of uncertainty is associated with our lack of knowledge as to how the field strength varies inside the star. Here, we point out that a recent study of 44 eclipsing binaries in the Kepler field by Cruz et al. may enable us for the first time to set an upper limit Bc on the field strengths inside the 88 stars in the sample. According to our magneto-convective model, the largest empirical inflations reported by Cruz et al. can be replicated if Bc is about 10 kG inside stars with masses greater than 0.65 MSun. On the other hand, in lower mass stars, especially those with masses less than 0.4 MSun, our model predicts that the largest empirical inflations may require significantly stronger fields, i.e. Bc approximately 100-300 kG.

Studies of the distant Universe are providing key insights into our understanding of the formation of galaxies. The advent of the James Webb Space Telescope (JWST) has significantly enhanced our observational capabilities, leading to an expanded redshift frontier, providing unprecedented detail in the characterization of early galaxies and enabling the discovery of new populations of accreting black holes. This review aims to provide an introduction to the basic processes and components that shape the observed spectra of galaxies, with a focus on their relevance to techniques with which high-redshift galaxies are selected. The review further introduces specific topics that have attracted significant attention in recent literature, including the discovery of highly efficient galaxy formation in the early Universe, the relation between galaxies and the process of reionization, new insights into the formation of the first stars and the enrichment of interstellar gas with heavy elements, and breakthroughs in our understanding of the origins of supermassive black holes.

Periodic Density Structures (PDS) observed in white-light coronagraphs represent a fundamental challenge to conventional solar wind paradigms. Through systematic analysis of multi-instrument observations and theoretical modeling, we demonstrate that coronal streamers operate as dual-nature systems: magnetohydrodynamic resonators that establish global periodicity through standing waves (122, 61, 41 minutes) and Laval nozzles that generate local flow structures through shock-driven oscillations (93, 47, 31, 23 minutes). The resonant mechanism dominates PDS formation, explaining their universal occurrence across 85\% of streamers, coherence over 10+ cycles, and persistence to 1 AU with only 0.1\% energy loss. Nozzle oscillations, while limited to 35\% of overexpanded streamers and maintaining only 1-2 cycle coherence, play crucial secondary roles in vortex formation and provide the essential converging-diverging geometry for supersonic solar wind acceleration. This dual-mechanism framework resolves longstanding puzzles in solar wind structuring while revealing the hierarchical organization of standing-wave and flow processes in astrophysical plasmas.

Many stars are components of triple-star systems, or of higher-order multiples. In such systems mass transfer is common, and when the transfer is dynamically unstable, a common envelope forms. As such, it is important to be able to compute the post-common-envelope orbital separations among the various stars comprising the system, and to determine whether the common envelope induces mergers and/or makes later mergers inevitable. In this paper we compute the results of common-envelope evolution for triples. We employ the SCATTER formalism, a new approach to the computation of post-common-envelope separations. This work has applications to gravitational mergers, Type Ia supernovae, and a broad range of highly energetic phenomena.

We examine Ca abundances in classical novae from spectroscopic observations spanning 65 years and investigate whether they are systematically high compared to those predicted by nova models. For the first time, we perform Monte Carlo simulations assessing the impact of nuclear reaction rate uncertainties on abundances predicted by multi-zone nova models. While the Ca abundances in the models are sensitive to variations of rates of the reactions 37Ar(p,gamma)38K and 38K(p,gamma)39Ca, the nuclear physics uncertainties of these reactions cannot account for the discrepancy between the observed and predicted Ca abundances in novae. Furthermore, the overabundance of Ca has important implications for measuring 7Be in nova ejecta, as Ca lines are used to estimate 7Be abundances. If the Ca abundance is incorrectly determined, it could lead to inaccurate 7Be abundance estimates. Possible alternative explanations for the observed Ca overabundance are discussed.

We revisit neutrino-matter coupling in the post-shock region of core-collapse supernovae by restoring nuclear recoil in coherent neutrino-nucleus scattering (CEvNS). The resulting local energy transfer (a few keV per ~10 MeV neutrino) accumulates across the ~100 km stalled-shock layer, yielding a total heating of 10^49-10^50 erg, comparable within an order of magnitude to the increment required to trigger shock revival in current multidimensional simulations. This indicates that the long-standing failure of isoenergetic transport schemes to revive the shock originates from their neglect of recoil kinematics. Because the momentum exchange in each scattering is tiny, the emergent neutrino spectra and lepton-number balance remain essentially unchanged. The result highlights nuclear recoil as a minimal yet physically grounded correction to standard neutrino transport, providing a self-consistent route toward reliable explosion modeling.

A question often arises as to why some solar flares are confined in the lower corona while others, termed eruptive flares, are associated with coronal mass ejections (CMEs). Here we intend to rank the importance of pre-flare magnetic parameters of active regions in their potentiality to predict whether an imminent flare will be eruptive or confined. We compiled a dataset comprising 277 solar flares of GOES-class M1.0 and above, taking place within 45 deg from the disk center between 2010 and 2023, involving 94 active regions. Among the 277 flares, 135 are confined and 142 are eruptive. Our statistical analysis reveals that the magnetic parameters that are most relevant to the flare category are: total unsigned magnetic flux $\Phi$, mean magnetic shear angle $\Theta$ along the polarity inversion line (PIL), photospheric free magnetic energy $E_f$, and centroid distance $d$ between opposite polarities. These four parameters are not independent of each other, but in combination, might be promising in distinguishing confined from eruptive flares. For a subset of 77 flares with high-gradient PILs, the area of high free energy regions ($A_{\mathrm{Hi}}$) becomes the most effective parameter related to the flare type, with confined flares possessing larger $A_{\mathrm{Hi}}$ than eruptive ones. Our results corroborate the general concept that the eruptive behavior of solar flares is regulated by an interplay between the constraining overlying flux, which is often dominant in both $\Phi$ and $E_f$ and related to $d$, and the current-carrying core flux, which is related to $\Theta$.

Fast radio bursts (FRBs) are transient signals exhibiting diverse strengths and emission bandwidths. Traditional single-pulse search techniques are widely employed for FRB detection; yet weak, narrow-band bursts often remain undetectable due to low signal-to-noise ratios (SNR) in integrated profiles. We developed DANCE, a detection tool based on cluster analysis of the original spectrum. It is specifically designed to detect and isolate weak, narrow-band FRBs, providing direct visual identification of their emission properties. This method performs density clustering on reconstructed, RFI-cleaned observational data, enabling the extraction of targeted clusters in time-frequency domain that correspond to the genuine FRB emission range. Our simulations show that DANCE successfully extracts all true signals with SNR~>5 and achieves a detection precision exceeding 93%. Furthermore, through the practical detection of FRB 20201124A, DANCE has demonstrated a significant advantage in finding previously undetectable weak bursts, particularly those with distinct narrow-band features or occurring in proximity to stronger bursts.

We report a measurement of the cosmic ray helium energy spectrum in the energy interval 0.16 -- 13 PeV, derived by subtracting the proton spectrum from the light component (proton and helium) spectrum obtained with observations made by the Large High Altitude Air Shower Observatory (LHAASO) under a consistent energy scale. The helium spectrum shows a significant hardening centered at $E \simeq$ 1.1 PeV, followed by a softening at $\sim$ 7 PeV, indicating the appearance of a helium `knee'. Comparing the proton and helium spectra in the LHAASO energy range reveals some remarkable facts. In the lower part of this range, in contrast to the behavior at lower energies, the helium spectrum is significantly softer than the proton spectrum. This results in protons overtaking helium nuclei and becoming the largest cosmic ray component at $E \simeq$ 0.7 PeV. A second crossing of the two spectra is observed at $E \simeq$ 5 PeV, above the proton knee, when helium nuclei overtake protons to become the largest cosmic ray component again. These results have important implications for our understanding of the Galactic cosmic ray sources.

The $\gamma$-ray from Giant molecular clouds (GMCs) is regarded as the most ideal tool to perform in-situ measurement of cosmic ray (CR) density and spectra in our Galaxy. We report the first detection of $\gamma$-ray emissions in the very-high-energy (VHE) domain from the five nearby GMCs with a stacking analysis based on a 4.5-year $\gamma$-ray observation with the Large High Altitude Air Shower Observatory (LHAASO) experiment. The spectral energy distributions derived from the GMCs are consistent with the expected $\gamma$-ray flux produced via CR interacting with the ISM in the energy interval 1 - 100 $~\rm$ TeV. In addition, we investigate the presence of the CR spectral `knee' by introducing a spectral break in the $\gamma$-ray data. While no significant evidence for the CR knee is found, the current KM2A measurements from GMCs strongly favor a proton CR knee located above 0.9$~\rm$ PeV, which is consistent with the latest measurement of the CR spectrum by ground-based experiments.

We report a long-term, high-cadence timing and spectral observation of the X-ray pulsar SMC X-1 using NinjaSat, a 6U CubeSat in low-Earth orbit, covering nearly a full superorbital cycle. SMC X-1 is a high-mass X-ray binary exhibiting a 0.7 s X-ray pulsar and a non-stationary superorbital modulation with periods ranging from approximately 40 to 65 days. Its peak luminosity of $1.3\times10^{39}$~\lumcgs\ makes it a local analogue of ultraluminous X-ray pulsars powered by supercritical accretion. We find that the spin-up rate during the high state remains consistent with the long-term average, with no significant correlation between spin-up rate and flux. This result indicates that the modulation is primarily geometric rather than accretion-driven. The hardness ratio and spectral shape are stable throughout the entire superorbital cycle, supporting obscuration by optically thick material or energy-independent scattering. In addition, the 2--20 keV pulse profile varies with superorbital phase, which may be explained either by variable covering fraction due to geometric obscuration, or by free precession of the neutron star. This represents the first complete measurement of spin-up rate and spectral evolution across a single superorbital cycle in SMC X-1, highlighting the scientific capability of CubeSat-based observatories.

We report the multiwavelength properties of eFEDS J084222.9+001000 (hereafter ID830), a quasar at $z=3.4351$, identified as the most X-ray luminous radio-loud quasar in the eROSITA Final Equatorial Depth Survey (eFEDS) field. ID830 shows a rest-frame 0.5-2 keV luminosity of $\log (L_\mathrm{0.5-2\,keV}/\mathrm{erg}~\mathrm{s}^{-1}) = 46.20 \pm 0.12$, with a steep X-ray photon index ($\Gamma =2.43 \pm 0.21$), and a significant radio counterpart detected with VLA/FIRST 1.4 GHz and VLASS 3 GHz bands. The rest-frame UV to optical spectra from SDSS and Subaru/MOIRCS $J$-band show a dust reddened quasar feature with $A_\mathrm{V} = 0.39 \pm 0.08$ mag and the expected bolometric AGN luminosity from the dust-extinction-corrected UV luminosity reaches $L_\mathrm{bol,3000}= (7.62 \pm 0.31) \times 10^{46}$ erg s$^{-1}$. We estimate the black hole mass of $M_\mathrm{BH} = (4.40 \pm 0.72) \times 10^{8} M_{\odot}$ based on the MgII$\lambda$2800 emission line width, and an Eddington ratio from the dust-extinction-corrected UV continuum luminosity reaches $\lambda_\mathrm{Edd,UV}=1.44 \pm 0.24$ and $\lambda_{\mathrm{Edd,X}} = 12.8 \pm 3.9$ from the X-ray luminosity, both indicating the super-Eddington accretion. ID830 shows a high ratio of UV-to-X-ray luminosities, $\alpha_\mathrm{OX}=-1.20 \pm 0.07$ (or $\alpha_\mathrm{OX}=-1.42 \pm 0.07$ after correcting for jet-linked X-ray excess), higher than quasars and little red dots in super-Eddington phase with similar UV luminosities, with $\alpha_\mathrm{OX}<-1.8$. Such a high $\alpha_\mathrm{OX}$ suggests the coexistence of a prominent radio jet and X-ray corona, in this high Eddington accretion phase. We propose that ID830 may be in a transitional phase after an accretion burst, evolving from a super-Eddington to a sub-Eddington state, which could naturally describe the high $\alpha_\mathrm{OX}$.

The most luminous and obscured quasars (QSOs) detected in infrared all-sky surveys could represent a key co-evolutionary phase from nuclear to circum-galactic (CG) scales in the formation of massive galaxies. In this context, Hot Dust Obscured Galaxies (Hot DOGs) at z ~2-4 provide a unique opportunity to study the link between cosmic mass assembly and nuclear accretion in high-z luminous QSOs/galaxies. W0410-0913 (hereafter W0410-09) is a luminous ($\rm ~L_{\rm bol} \sim 6.4 \times10^{47} \rm erg\ s^{-1}$) obscured QSO at z = 3.631, with a 30 kpc CG Ly$\alpha$ nebula (CGLAN), smaller than the ~ 100 kpc nebulae around unobscured Type-I QSOs, and an exceptional overdense environment of ~ 19 Ly$\alpha$ emitters (LAEs) within 300 kpc and $\pm$ 200 $\rm km ~s^{-1}$ of the Hot DOG. We aim to detect and characterize nuclear accretion in W0410-09 and its environment. Exploiting a deep proprietary ~280 ks Chandra observation, using empirical and physically motivated models for obscured sources, we show that W0410-09 exhibits Compton-thick obscuration ($\rm~ N_H > 10^{24} \rm cm^{-2}$) and high intrinsic luminosity ($\rm ~L_{2-10} > 10^{45} \rm erg ~s^{-1}$), making it one of the most luminous obscured QSOs at z $>$ 3.5. With the exclusion of W0410-09 we do not detect X-ray emission from any of the 19 LAEs, except for a 3$\sigma$ signal in the 6-7 keV rest-frame band, interpreted as Fe K$\alpha$ emission, suggesting the presence of heavily obscured yet undetected AGN emission in several LAEs. Including W0410-09, the estimated AGN fraction is $f_{\rm AGN}^{\rm LAE} = 5^{+12}_{-4}$%, potentially up to ~35% if unresolved obscured AGN are considered as suggested by the Fe K$\alpha$ line detection. We conclude that W0410-09 is in a critical transitional blow-out phase, during which powerful QSO-driven outflows are clearing the nuclear obscuration, ultimately leading to an unobscured luminous quasar.

The presence of broad wings in the H$\alpha$} line is commonly used as a diagnostic of the presence and properties of galactic winds from star-forming galaxies. However, the accuracy of this approach has not been subjected to extensive testing. In this paper, we use high-resolution simulations of galactic wind launching to calibrate the extent to which broad H$\alpha$} wings can be used to infer the properties of galactic outflows. For this purpose, we analyse a series of high-resolution wind simulations from the QED suite spanning two orders of magnitude in star formation surface density ($\Sigma_\mathrm{SFR}$). We show that the broad component of H$\alpha$} emission correlates well with the wind mass flux at heights $\sim1$ kpc above the galactic plane, but that the correlation is poor at larger distances from the plane, and that even at 1 kpc the relationship between mass flux and surface brightness of broad H$\alpha$} is significantly sub-linear. The sub-linear scaling suggests that the electron column density in the wind increases systematically with outflow strength, and that the conventional assumption of constant electron density in the wind leads to a systematic overestimate of how steeply mass loading factors depend on $\Sigma_\mathrm{SFR}$. We provide empirical scaling relations that observers can apply to correct for this effect when converting H$\alpha$} measurements to mass outflow rates. Finally, we use synthetic observations of the density-diagnostic $[\mathrm{S_{II}}]\,\lambda\lambda6716,6731$ doublet to show that using this diagnostic only slightly improves estimates of wind outflow rates compared to the naive assumption of constant electron density, and performs significantly worse than the empirical correlation we provide.

The Lorentz invariance violation (LIV) predicted by some quantum gravity theories would manifest as an energy-dependent speed of light, which may potentially distort the observed temporal profile of photons from astrophysical sources at cosmological distances. The dispersion cancellation (DisCan) algorithm offers a powerful methodology for investigating such effects by employing quantities such as Shannon entropy, which reflects the initial temporal characteristics. In this study, we apply the DisCan algorithm to search for LIV effects in the LHAASO observations of GRB 221009A, combining data from both the WCDA and KM2A detectors that collectively span an energy range of $\sim 0.2-13$ TeV. Our analysis accounts for the uncertainties from both energy resolution and temporal binning. We derive $95\%$ confidence level lower limits on the LIV energy scale of $E_{\rm{QG}}/10^{19}~\text{GeV}>21.1$ (13.8) for the first-order subluminal (superluminal) scenario, and $E_{\rm{QG}}/10^{11}~\text{GeV}> 14.9$ (13.7) for the second-order subluminal (superluminal) scenario.

We present a study of the cold molecular gas kinematics in the inner ~ 4-7 kpc (projected sizes) of three nearby Seyfert galaxies, with AGN luminosities of ~ 10$^{44}$ erg/s, using observations of the CO(2-1) emission line, obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) at ~ 0.5-0.8$^{\prime\prime}$ (~ 150-400 pc) spatial resolutions. After modeling the CO profiles with multiple Gaussian components, we detected regions with double-peak profiles that exhibit kinematics distinct from the dominant rotational motion. In NGC 6860, a molecular outflow surrounding the bipolar emission of the [O III] ionized gas is observed extending up to $R_{out}$ ~ 560 pc from the nucleus. There is evidence of molecular inflows along the stellar bar, although an alternative scenario, involving a decoupled rotation in a circumnuclear disk (CND) can also explain the observed kinematics. Mrk 915 shows double-peak CO profiles along one of its spiral arms. Due to its ambiguous disk orientation, part of the CO emission can be interpreted as a molecular gas inflow or an outflow reaching $R_{out}$ ~ 2.8 kpc. MCG -01-24-012 has double-peak profiles associated with a CND, perpendicular to the [O III] bipolar emission. The CO in the CND is rotating while outflowing within $R_{out}$ ~ 3 kpc, with the disturbances possibly being caused by the passage of the ionized gas outflow. Overall, the mass inflow rates are larger than the accretion rate needed to produce the observed luminosities, suggesting that only a fraction of the inflowing gas ends up feeding the central black holes. Although we found signatures of AGN feedback on the cold molecular phase, the mass outflow rates of ~ 0.09-3 M$_\odot$/yr indicate an overall weak impact at these AGN luminosities. Nonetheless, we may be witnessing the start of the depletion and ejection of the molecular gas reservoir that has accumulated over time.

PSR J1928+1815, the first recycled pulsar-helium (He) star binary discovered by the Five-hundred-meter Aperture Spherical radio Telescope, consists of a 10.55 ms pulsar and a companion star with mass $1-1.6\,M_{\sun}$ in a 0.15-day orbit. Theoretical studies suggest that this system originated from a neutron star (NS) intermediate-mass or high-mass X-ray binary that underwent common envelope (CE) evolution, leading to the successful ejection of the giant envelope. The traditional view is that hypercritical accretion during the CE phase may have recycled the NS. However, the specific mechanism responsible for accelerating its spin period remains uncertain due to the complex processes involved in CE this http URL this study, we investigate the influence of Roche lobe overflow (RLO) accretion that takes place prior to the CE phase on the spin evolution of NSs. Our primary objective is to clarify how this process affects the spin characteristics of pulsars. We utilized the stellar evolution code \texttt{MESA} and the binary population synthesis code \texttt{BSE} to model the formation and evolution of NS-He star binaries. We calculated the distributions of the orbital period, He star mass, NS spin period, and magnetic field for NS + He star systems in the Galaxy. Our results indicate that RLO accretion preceding the CE phase could spin up NSs to millisecond periods through super-Eddington accretion. Considering a range of CE efficiencies $\alpha_{\rm CE}$ from 0.3 to 3, we estimate the birthrate (total number) of NS + He star systems in our Galaxy to be 9.0$\times 10^{-5}$ yr$^{-1}$ (626 systems) to 1.9$\times 10^{-4}$ yr$^{-1}$ (2684 systems).

We present an emulator suite for the one- and two-loop cold dark matter power spectrum from the Effective Field Theory of Large Scale Structures (EFTofLSS). Specifically, we emulate separately the various contributions to the one- and two-loop parts of the power spectrum, leaving out the possible counterterms which can be added as multiplicative prefactors. By leaving the time-dependence of the counterterms unspecified at the emulation stage, our technique has the advantage of being extremely versatile in fitting any type of counterterm parametrisation to data, or to simulations, without having to change the emulator. We construct our emulators using the method of symbolic regression which results in functions that can be used directly in computer code, while achieving errors of better than $0.5\%$ within the $k$-range of validity of EFT and maintaining ultra-fast computational evaluation of less than $\sim5\times10^{-4}s$ on a single core.

Ram pressure stripping (RPS) plays a crucial role in shaping galaxy evolution in dense environments, yet its impact on the molecular and dusty phases of the interstellar medium remains poorly understood. We present JWST/NIRCam 3.3 micrometres PAH emission maps for the nine most striking RPS galaxies in the Abell 2744 cluster at redshift z_cl = 0.306, tracing the effects of environmental processes on small dust grains. Exploiting multi-band JWST/NIRCam and HST photometry, we perform spatially-resolved UV to mid-infrared spectral energy distribution (SED) fitting, characterising stellar populations in both galactic disks and clumps detected in the stripped tails. We detect PAH_3.3 mission in eight of the nine galaxies at 5 sigma, with morphologies revealing disk truncation and elongation along the RPS direction. In three galaxies, PAH_3.3 emission is also found in star-forming clumps embedded in the stripped tails up to a distance of 40 kpc. Star formation rates inferred from PAH_3.3 emission agree with those derived from SED fitting averaged over the past 100 Myr within an intrinsic scatter of 0.4 dex, but the relation appears to be age dependent. The spatial correlation between PAH strength, stellar age, and SFR - consistent across disks and tails - demonstrates that PAH-carrying molecules can survive and be stripped by ram pressure. Finally, age gradients revealed by the SED fitting provide the first observational evidence outside the Local Universe for the fireball model of star formation in stripped clumps. This work represents the first detailed study of PAH emission in cluster galaxies, offering new insights into the fate of dust and star formation in extreme environments.

Open clusters have been extensively used as tracers of Galactic chemical evolution, as their constituent stars possess shared characteristics, including age, Galactocentric radius, metallicity, and chemical composition. By examining the trends of elemental abundances with metallicity, age, and Galactocentric radius, valuable insights can be gained into the distribution and nucleosynthetic origins of chemical elements across the Galactic disc. The infrared domain in particular facilitates the observation of some elemental abundances that can be challenging or impossible to discern in the optical, for example K and F. The objective of this study is to derive the stellar parameters and elemental abundances of up to 23 elements in 114 stars spanning 41 open clusters using high-resolution infrared spectroscopy. In addition, the present study aims to examine the chemical evolution of the Galactic disc. This is achieved by investigating radial abundance gradients, variations in abundance between clusters, and the dependence of chemical abundances on cluster age.

Gamma-ray bursts (GRBs) are extremely bright phenomena powered by relativistic jets arising from explosive events at cosmological distances. The nature of the jet and the configuration of the local magnetic fields are still unclear, with the distinction between different models possibly provided by the detection of early-time polarisation. Past observations do not agree on a universal scenario describing early-time polarisation in GRB afterglows, and new studies are necessary to investigate this open question. We present here the discovery of GRB\,240419A, its redshift determination of $z=5.178$, its early-time optical polarimetry observations, and the multi-wavelength monitoring of its afterglow. We analysed three epochs of polarimetric data to derive the early-time evolution of the polarisation. The multi-wavelength light curve from the X-rays to the near-infrared band was also investigated to give a broader perspective on the whole event. We find a high level of polarisation, $P=6.97^{+1.84}_{-1.52}$\,\%, at 1740~s after the GRB trigger, followed by a slight decrease up to $P=4.81^{+1.87}_{-1.53}$\,\% at 3059~s. On the same timescale, the polarisation position angle is nearly constant. The multi-band afterglow at the time of the polarisation measurements is consistent with a forward shock (FS), while the earlier evolution at $t-t_0\lesssim700$ s can be associated with the interplay between the forward and the reverse shocks or with energy injection. The detected polarised radiation when the afterglow is FS-dominated and the stable position angle are consistent with an ordered magnetic field plus a turbulent component driven by large-scale magnetohydrodynamic instabilities. The lack of a jet break in the light curve prevents a comparison of the polarisation temporal evolution with theoretical expectations from magnetic fields amplified by microscopic-scale turbulence, limiting ...

TOI-282 is a bright (V=9.38) F8 main-sequence star known to host three transiting long-period ($P_b$=22.9 d, $P_c$=56.0 d, and $P_d$=84.3 d) small ($R_p\approx$ 2-4 $R_{\oplus}$) planets. The orbital period ratio of the two outermost planets, namely TOI-282 c and d, is close to the 3:2 commensurability, suggesting that the planets might be trapped in a mean motion resonance. We combined space-borne photometry from the TESS telescope with high-precision HARPS and ESPRESSO Doppler measurements to refine orbital parameters, measure the planetary masses, and investigate the architecture and evolution of the system. We performed a Markov chain Monte Carlo joint analysis of the transit light curves and radial velocity time series, and carried out a dynamical analysis to model transit timing variations and Doppler measurements along with N-body integration. In agreement with previous results, we found that TOI-282 b, c, and d have radii of $R_b=2.69 \pm 0.23 \ R_{\oplus}$, $R_c=4.13^{+0.16}_{-0.14} \ R_{\oplus}$, and $R_d=3.11 \pm 0.15 \ R_{\oplus}$, respectively. We measured planetary masses of $M_b=6.2\pm1.6 \ M_{\oplus}$, $M_c=9.2\pm2.0 \ M_{\oplus}$, and $M_d=5.8^{+0.9}_{-1.1} \ M_{\oplus}$, which imply mean densities of $\rho_b=1.8^{+0.7}_{-0.6} \ \text{g cm}^{-3}$, $\rho_c=0.7 \pm 0.2 \ \text{g cm}^{-3}$, and $\rho_d=1.1^{+0.3}_{-0.2} \ \text{g cm}^{-3}$, respectively. The three planets may be water worlds, making TOI-282 an interesting system for future atmospheric follow-up observations with JWST and ELT.

WASP-69b and KELT-11b are two low-density hot Jupiters, which are expected to show strong atmospheric features in their transmission spectra. Such features offer valuable insights into the chemical composition, thermal structure, and cloud properties of exoplanet atmospheres. High-resolution spectroscopic observations can be used to study the line-forming regions in exoplanet atmospheres and potentially detect signals despite the presence of clouds. We aimed to detect various molecular species and constrain the chemical abundances and cloud deck pressures using high-resolution spectroscopy. We observed multiple transits of these planets with CARMENES and applied the cross-correlation method to detect atmospheric signatures. Further, we used an injection-recovery approach and retrievals to place constraints on the atmospheric properties. We detected a tentative H$_2$O signal for KELT-11b but not for WASP-69b, and searches for other molecules such as H$_2$S and CH$_4$ resulted in non-detections for both planets. By investigating the signal strength of injected synthetic models, we constrained which atmospheric abundances and cloud deck pressures are consistent with our cross-correlation results. In addition, we show that a retrieval-based approach leads to similar constraints of these parameters.

The center-to-limb variations (CLVs) of photospheric and chromospheric spectral lines were obtained in 2025 July and August using drift scans from the echelle spectrograph of the 0.7 m Vacuum Tower Telescope at the Observatorio del Teide (ODT) in Tenerife, Spain. This instrument can observe four spectral regions simultaneously, enabling multi-line spectroscopy with high spectral resolution of various activity features and the quiet Sun in the lower solar atmosphere. The initial results of Halpha observations demonstrate the diagnostic potential of drift scans obtained with a ground-based, high-resolution telescope. Data products include spectroheliograms and maps of physical parameters such as line-of-sight velocity, line width, and line-core intensity. The combination of the CLV from photospheric and chromospheric lines, as well as the wide range of formation heights of the selected lines, renders this dataset ideal for characterizing stellar and exoplanet atmospheres.

This work investigates the decayless kink oscillations of solar coronal loops and examines possible changes in their behaviour in active regions (ARs) before powerful solar flares (M- and X-class) and in the absence of powerful flares. To this end, we analysed 14 ARs with powerful flares and 14 ARs without powerful flares. For each event, images obtained in the 171 Åand 94 ÅAIA/SDO channels with 12-second cadence for 4 hours before the flare were retrieved and analysed. For ARs without powerful flares, arbitrary time intervals of similar duration were considered for comparison. Since the decayless oscillations have a very low amplitude (1-2 AIA/SDO pixels), we used the Motion Magnification technique to amplify the amplitude of these oscillations. Time-distance maps were constructed from the processed images in the 171 Åchannel, from which oscillatory patterns were extracted 'manually'. Wavelet analysis was performed to check for changes in the oscillation period. No systematic changes were found. No obvious differences in the behaviour of oscillations in ARs with and without powerful flares were detected either. Additional information was obtained on coronal mass ejections (CMEs) from ARs in the vicinity of the time intervals under consideration. Based on the results of the analysis of a small sample of events, we came to the preliminary conclusion that the registration and analysis of decayless kink oscillations of high (~ 100-600 Mm) coronal loops based on this methodology is not promising for predicting powerful flares and CMEs.

The Tayler-Spruit dynamo (TSD) is able to generate a small-scale magnetic field in the differentially rotating stably stratified layers of stars and was recently observed in numerical simulations. In parallel, the propagation of internal gravity waves in stars can be modified in the presence of a magnetic field. Here we first want to estimate the interaction between a magnetic field generated by the TSD and internal gravity waves in the radiative core of low-mass stars. This allows us to then characterise the effect of this interplay on the observed standing modes spectrum and on the internal transport of angular momentum by progressive waves. To do this, we use the STAREVOL evolution code to compute the structure of low-mass rotating stars along their evolution. In particular, we implement a formalism to describe the TSD and estimate the regions where the generated magnetic field is strong enough to change the identity of internal gravity waves to magneto-gravity waves. In addition, we evaluate the possible limitation of angular momentum transport by the combined action of rotation and magnetism. We show that along the pre-main sequence and main-sequence evolution, the lowest frequencies of the excited gravity wave spectrum could be converted to magneto-gravity waves by the magnetic field generated by the TSD. During the red-giant branch we find that most of the excited spectrum of progressive internal gravity waves could be converted into magneto-gravity waves in the very central region.

This doctoral thesis studies stellar multiplicity in the solar neighborhood (d < 10 pc) and in systems hosting planets (d < 100 pc). Using data from the Washington Double Star Catalogue, Gaia DR3, and a comprehensive literature review, it builds the most complete and homogeneous sample of multiple systems within 10 pc. Multiplicity and companion fractions are derived with reduced uncertainties, providing improved statistical reliability. The analysis of orbital periods from one day to millions of years shows that the log-normal cumulative distribution can be seen as a modern revision of Öpik's law. A key contribution is the study of wide binaries ({\rho} > 1000 arcsec) with Gaia DR3, expanding the known sample by over an order of magnitude and improving astrometric precision. Newly identified companions, including ultracool dwarfs at the M-L boundary and a hot white dwarf, refine the distinction between true binaries and unrelated young moving-group members. The thesis also explores the effect of multiplicity on exoplanetary systems within 100 pc. New stellar companions are found in known planetary systems, with separations for over 200 pairs and parameters compiled for 276 exoplanets. Compared to single-star systems, multiple systems host more massive, short-period, and high-eccentricity planets. About 22% of exoplanetary systems have stellar companions, with significant (> 4 {\sigma}) correlations between high eccentricities and small projected separations, and a weaker (> 2 {\sigma}) trend showing that massive planets (M > 40 M_Earth) orbit closer in multiple systems. Finally, a review of Giovanni Battista Hodierna's 17th-century catalogues shows he compiled the first list of multiple systems over a century earlier than previously believed, advancing the understanding of stellar multiplicity and its influence on planetary formation.

We study the stellar mass function (SMF) of quiescent and star-forming galaxies and its dependence on morphology in 10 redshift bins at $0.2<z<5.5$ using the COSMOS2025 catalog built from $0.54 \, {\rm deg}^2$ JWST imaging from COSMOS-Web. Galaxies are selected by type using the $NUVrJ$ rest-frame color diagram and classified morphologically by bulge-to-total light ratio ($B/T$). The quiescent SMF shows rapid early build-up, with the most massive systems (${\rm log}(M_{\star}/{\rm M_{\odot}})\gtrsim11$) assembled by $z\sim1$ and evolving little since. The star-forming SMF evolves more slowly, following a mass-evolution scenario where galaxies grow via star formation and quench at the characteristic mass $\log(M^{*}/{\rm M}_{\odot})\sim10.6$. Bulge systems ($B/T>0.6$) dominate the quiescent SMF at ${\rm log}(M_{\star}/{\rm M_{\odot}})>10$ at all redshifts, while disks ($B/T<0.2$) dominate at ${\rm log}(M_{\star}/{\rm M_{\odot}})<9$. However, most bulge-dominated galaxies are star-forming, with their fraction increasing with redshift and decreasing mass, consistent with being progenitors of quiescent bulges. We find evidence for environmental quenching onset at $z\sim3$ from the upturn in the quiescent SMF at ${\rm log}(M_{\star}/{\rm M_{\odot}})<9.5$, contributed by disk-dominated galaxies consistent with satellite quenching that retains disk morphologies. Number densities of ${\rm log}(M_{\star}/{\rm M_{\odot}})>10$ quiescent galaxies are lower than recent literature by $0.1-0.7$ dex, but agree well with simulations at $2<z<3$. At $z>3$, simulations increasingly underpredict observations. Finally, we build an empirical model describing galaxy number density evolution by parametrizing quenching rates, baryon conversion efficiency, and bulge formation. Our model supports a scenario where star-forming galaxies grow central bulges before quenching in massive halos.

The scaling laws reveal the underlying structural similarities shared by astrophysical systems across vastly different scales. In black hole accretion systems, the scaling relations between the characteristic damping timescales (CDTs) of light curves and black hole mass offer valuable insights into the underlying physical structure of accretion disks. We investigate, for the first time, the long-term hard X-ray variability of black hole and neutron star accretion systems using light curves from the \textit{Swift} Burst Alert Telescope 157-month catalog. Applying a damped random walk model, we measure CDTs for 39 Seyfert galaxies, 17 blazars, 82 X-ray binaries, and one tidal disruption event. Unexpectedly, these CDTs span months to years but with a mass-independent feature, in contrast to well-established scaling laws. This puzzling phenomenon can be attributed to conductive timescales arising from disk--corona interactions, instead of the intrinsic accretion disk processes characterized by scaling laws, and it may further modulate jet emission in blazars. This result demonstrates thermal conduction as a key mechanism driving hard X-ray variability and offers new observational evidence for the disk--corona--jet connection.

The papers included in this Focus Point collection are devoted to the studies on the cosmological tensions and challenges stimulated by the latest observational data. The first results of the LARES-2 laser ranging satellite on the high precision testing of the frame-dragging effect predicted by General Relativity are presented. The data on the S-stars monitoring in the Galactic center obtained by GRAVITY collaboration were analysed within the Physics-informed neural network (PINN) approach. The results enabled to probe the role of the cosmological constant, of the dark matter, the star cluster in the core of the Galaxy obtaining an upper limit for the star density. The topics include the conversion of high-frequency relic gravitational waves into photons in cosmological magnetic field, cosmological gravitational waves stochastic background generation through the spontaneous breaking of a global baryon number symmetry, observational predictions of the Starobinsky inflation model and other studies.

The IceCube Observatory comprises a cubic-kilometer particle detector deep in the Antarctic ice and the cosmic-ray air-shower array IceTop at the surface above. Previous analyses of the cosmic-ray composition have used coincident events with IceTop detecting the electromagnetic shower footprint as well as GeV muons, while the sensors submerged in the ice measure the TeV muons from the same events. The energy range of previous composition analyses, however, has been limited to 3 PeV primary energy and above, whereas the IceTop all-particle energy spectrum has been extended down to 250 TeV. This contribution presents a method to reconstruct the combined spectrum of cosmic-ray protons and helium nuclei, starting at 200 TeV primary energy. The resulting H+He spectrum closes the gap in the measurements of light cosmic rays between IceCube as well as KASCADE and experiments measuring in the TeV energy range, such as DAMPE and HAWC.

We present results of an extensive suite of numerical simulations that probe square-tiled microwave absorber performance as a function of material properties, frequency, geometry, and unit cell size. The work, which probes both specular reflection and total absorption, highlights the critical importance of the absorber scale size relative to the incidence wavelength while suggesting that material properties have a comparatively weaker impact on overall performance. We show that some absorber designs can achieve 99.5-99.9% frequency-averaged absorption across the 70 to 200 GHz range for normal incidence and that low specular reflectance does not necessarily guarantee optimal absorption performance. Our results indicate that exponential, Klopfenstein, and linear impedance tapers provide comparable performance as long as a unit cell size of 1 to 4 mm is chosen. Simulation results are validated against measurements of specular reflectance.

Dipolar (l=1) mixed modes revealed surprisingly weak differential rotation between the core and the envelope of evolved solar-like stars. Quadrupolar (l=2) mixed modes also contain information on the internal dynamics, but are very rarely characterised due to their low amplitude and the challenging identification of adjacent or overlapping rotationally split multiplets affected by near-degeneracy effects. We aim to extend broadly used asymptotic seismic diagnostics beyond l=1 mixed modes by developing an analogue asymptotic description of l=2 mixed modes, explicitly accounting for near-degeneracy effects that distort their rotational multiplets. We derive a new asymptotic formulation of near-degenerate mixed l=2 modes that describes off-diagonal terms representing the interaction between modes of adjacent radial orders. We implement the formalism within a global Bayesian mode-fitting framework, for a direct fit of all l=0,1,2 modes in the power spectrum density. We are able to asymptotically model the asymmetric rotational splitting present in various radial orders of l=2 modes observed in young red giant stars without the need for any numerical stellar modelling. Applied to the Kepler target KIC 7341231, our formalism yields core and envelope rotation rates consistent with previous numerical modelling, while providing improved constraints from the global and model-independent approach. We also characterise the new target KIC 8179973, measuring its rotation rate and mixed-mode parameters for the first time. The global fit allows for much better precision than standard methods, yielding better constraints for rotation inversions. We place the first observational constraints on the asymptotic l=2 mixed mode parameters (DPi_2,q_2,eps_g2), paving the way towards the use of asymptotic seismology beyond l=1 mixed modes.

Gravitational-wave observations of massive, rapidly spinning binary black holes mergers provide increasing evidence for the dynamical origin of some mergers. Previous studies have interpreted the mergers with primary mass $\gtrsim45\,M_\odot$ as being dominated by hierarchical, second-generation mergers, with rapidly spinning primaries being the products of previous black hole mergers assembled in dense stellar clusters. In this work, we reveal confident evidence of another subpopulation with rapid and isotropic spins at low mass containing the two exceptional events GW241011 and GW241110, consistent with a hierarchical merger hypothesis. Our result suggests the mass distribution of the second-generation black holes is peaked at low primary masses of $\sim16\,M_\odot$ rather than $\gtrsim45\,M_\odot$ in the pair-instability gap. Such low-mass second-generation black holes must be formed from the merger of even lighter first-generation black holes, implying that dense, metal-rich stellar environments contribute to the binary black hole population. By separating the contamination of higher-generation black holes, our result reveals the primary mass distribution of first-generation black holes formed from stellar collapse, which shows a significant dip between $\sim12\,M_\odot$ to $\sim20\,M_\odot$. This may indicate a dearth of black holes due to variation in the core compactness of the progenitor.

We present \texttt{EMPEROR}, an open-source Python framework designed for efficient exoplanet detection and characterisation with radial velocities (RV). \texttt{EMPEROR} integrates Dynamic Nested Sampling (DNS) and Adaptive Parallel Tempering (APT) Markov Chain Monte Carlo (MCMC), supporting multiple noise models such as Gaussian Processes (GPs) and Moving Averages (MA). The framework enables systematic model comparison using statistical metrics, including Bayesian evidence ($\ln{\mathcal{Z}}$) and Bayesian Information Criterion (BIC), while providing automated, publish-ready visualisations. \texttt{EMPEROR} is evaluated across three distinct systems to assess its capabilities in different detection scenarios. Sampling performance, model selection, and the search for Earth-mass planets are evaluated in data for 51 Pegasi, HD 55693 and Barnard's Star (GJ 699). For 51 Pegasi, APT achieves an effective sampling increase over DNS by a factor 3.76, while retrieving tighter parameter estimates. For HD 55693 the stellar rotation $P_{\text{rot}}=29.72^{+0.01}_{-0.02}$ and magnetic cycle $P_{\text{mag}}=2557.0^{+70.1}_{-36.7}$ are recovered, while demonstrating the sensitivity of $\ln{\mathcal{Z}}$ to prior selection. For Barnard's star, several noise models are compared, and the confirmed planet parameters are successfully retrieved with all of them. The best model shows a period of 3.1536$\pm$0.0003~d, minimum mass of 0.38$\pm$0.03 M$_{\rm{\oplus}}$, and semi-major axis of 0.02315$\pm$0.00039~AU. Purely statistical inference might be insufficient on its own for robust exoplanet detection. Effective methodologies must integrate domain knowledge, heuristic criteria, and multi-faceted model comparisons. The versatility of \texttt{EMPEROR} in handling diverse noise structures, its systematic model selection, and its improved performance make it a valuable tool for RV exoplanetary studies.

We revisit the quadratic inflationary potential by introducing a minimal higher-order correction obtained through a simple field redefinition, leading to the potential V(chi) = (1/2) m^2 * (chi - (gamma/14) * chi^7)^2. While the uncorrected quadratic model predicts n_s approximately 0.967 and r approximately 0.13, in strong tension with CMB data, the corrected potential yields n_s approximately 0.965 and r approximately 0.036, fully consistent with Planck 2018 constraints. Beyond inflationary observables, the deformation also impacts the reheating phase. In the quadratic case, reheating corresponds to a matter-like regime with w_reh = 0, whereas the corrected potential gives w_reh approximately -0.011, a slightly softer equation of state. This modification raises the reheating temperature by a factor of about 3.4 (for N_reh = 10), or equivalently extends the reheating duration at fixed temperature. Our results demonstrate that even a minimal higher-order correction is sufficient to reconcile the quadratic model with observations while providing a more consistent post-inflationary history, highlighting the relevance of controlled deformations of simple inflationary scenarios.

We present results from intensive (x3 daily), three-month-long X-ray, UV and optical monitoring of the bright Seyfert active galactic nucleus (AGN) MCG+08-11-11 with Swift, supported by optical-infrared ground-based monitoring. The 12 resultant, well-sampled, lightcurves are highly correlated; in particular, the X-ray to UV correlation r_max = 0.85 is, as far as we know, the highest yet recorded in a Seyfert galaxy. The lags increase with wavelength, as expected from reprocessing of central high-energy emission by surrounding material. Our lag spectrum is much shallower than that obtained from an optical monitoring campaign conducted a year earlier when MCG+08-11-11 was approximately 4 times brighter. After filtering out long-term trends in the earlier optical lightcurves we recover shorter lags consistent with our own - demonstrating concurrent reverberation signals from different spatial scales and the luminosity dependence of the measured lags. We use our lag spectrum to test several physical models, finding that disc reprocessing models cannot account for the observed 'excess' lags in the u and r-i-bands that are highly indicative of the Balmer and Paschen continua produced by reprocessing in the broad line region (BLR) gas. The structure seen in both the variable (rms) and lag spectra, and the large time delay between X-ray and UV variations (approximately 2 days) all suggest that the BLR is the dominant reprocessor. The hard X-ray spectrum (Gamma approximately 1.7) and faint, red, UV-optical spectrum both indicate that the Eddington accretion ratio is low: approximately 0.03. The bolometric luminosity then requires that the black hole mass is substantially greater than current reverberation mapping derived estimates.

Magnetic BA stars host dipole-like magnetospheres. When detected as radio sources, their luminosities correlate with the magnetic field and rotation. Rotation is crucial because the mechanism undergirding the relativistic electron production is powered by centrifugal breakouts. CBOs occur wherever magnetic tension does not balance centrifugal force; the resulting magnetic reconnection provides particle acceleration. To investigate how physical conditions at the site of the CBOs affect the efficiency of the acceleration mechanism, we broadly explore the parameter space governing radio emission by increasing the sample of radio-loud magnetic stars. High-sensitivity VLA observations of 32 stars were performed in the hope of identifying new centrifugal magnetospheres and associated CBOs. We calculated gyro-synchrotron spectra using 3D modeling of a dipole-shaped magnetosphere. We evaluated combinations of parameters. The number of relativistic electrons was constrained by the need to produce the emission level predicted by the scaling relationship for the radio emission from magnetic BA stars. About half of the observed stars were detected, with luminosities in agreement with the expected values, reinforcing the robust nature of the scaling relationship for CBO-powered radio emission. Comparing the competing centrifugal and magnetic effects on plasma locked in a rigidly rotating magnetosphere, we located the site of CBOs and inferred the local plasma density. We then estimated the efficiency of the acceleration mechanism needed to produce enough non-thermal electrons to support the radio emission level. Given a constant acceleration efficiency, relativistic electrons represent a fixed fraction of the local thermal plasma. Thus, dense magnetospheres host more energetic particles than less dense ones; consequently, with other parameters similar, they are intrinsically brighter radio sources.

Modeling the solar atmosphere is challenging due to its layered structure and multi-scale dynamics. We aim to validate the new radiative MHD code MAGEC, which combines the MANCHA and MAGNUS codes into a finite-volume, shock-capturing framework, and to test its performance through 2D simulations of magneto-convection. MAGEC is MPI-parallelized and includes improvements for coronal modeling, such as LTE radiative losses and a hyperbolic treatment of thermal conduction that mitigates restrictive time steps. We also estimated its numerical viscosity and resistivity. To assess robustness, we performed 2D simulations covering a domain from 2 Mm below the surface to 18.16 Mm into the corona, using both open and closed magnetic-field configurations. For each case, we analyzed steady-state temperature profiles and the contributions to the internal-energy balance at different heights. A separate experiment examined the role of perpendicular thermal conduction. MAGEC reproduced the expected temperature stratification set by boundary conditions and magnetic geometry, and all simulations reached thermal equilibrium. Open-field cases produced higher coronal temperatures than closed, arcade-like fields. Analysis of the explicit and implicit energy terms clarified their relative effects on heating and cooling. Perpendicular thermal conduction, often neglected in coronal models, was found to influence plasma dynamics near reconnection; although local effects are small, they can cumulatively modify the average coronal temperature. These results show that MAGEC is a reliable and efficient tool for radiative MHD simulations, well suited to capturing the shocks and dynamic processes of the solar atmosphere.

Velocity distribution functions (VDF) are an essential observable for studying kinetic and wave-particle processes in solar wind plasmas. To experimentally distinguish modes of heating, acceleration, and turbulence in the solar wind, precise representations of particle phase space VDFs are needed. In the first paper of this series, we developed the Slepian Basis Reconstruction (SBR) method to approximate fully agyrotropic continuous distributions from discrete measurements of electrostatic analyzers (ESAs). The method enables accurate determination of plasma moments, preserves kinetic features, and prescribes smooth gradients in phase space. In this paper, we extend the SBR method by imposing gyrotropic symmetry (g-SBR). Incorporating this symmetry enables high-fidelity reconstruction of VDFs that are partially measured, as from an ESA with a limited field-of-view (FOV). We introduce three frameworks for g-SBR, the gyrotropic Slepian Basis Reconstruction: (A) 1D angular Slepian functions on a polar-cap, (B) 2D Slepian functions in a Cartesian plane, and (C) a hybrid method. We employ model distributions representing multiple anisotropic ion populations in the solar wind to benchmark these methods, and we show that the g-SBR method produces a reconstruction that preserves kinetic structures and plasma moments, even with a strongly limited FOV. For our choice of model distribution, g-SBR can recover $\geq90\%$ of the density when only $20\%$ is measured. We provide the package \texttt{gdf} for open-source use and contribution by the heliophysics community. This work establishes direct pathways to bridge particle observations with kinetic theory and simulations, facilitating the investigation of gyrotropic plasma heating phenomena across the heliosphere.

We present high-frequency, full-polarisation Jansky Very Large Array (VLA) radio data at X-band of the radio relic: MACS J0717.5+3745. Radio relics trace shock waves in the intracluster medium (ICM) produced during mergers. Understanding the physical characteristics of relics is important for determining their nature, whether for example they are thermal ICM electrons that are accelerated, or whether they are fossil electrons re-accelerated by a merger event. Radio spectropolarimetric analysis, such as the Stokes QU-fitting, provides a diagnostic of the nature and structure of the magnetized plasma internal or external to the source, with important implications for theoretical models. The high-frequency polarisation analysis presented here shows, for the first time, a change in the magneto-ionic structure compared to the low-frequency data available in the literature. These high-frequency, polarised data could be interpreted also with an internal depolarisation behaviour and this new finding may be used to investigate possible particle acceleration mechanism. If that is true, the change in the behaviour of the polarised signal could be tracing physical properties of a population of non-thermal particles that are undergoing to a re-acceleration of particles in the relic by large-scale internal shocks of Active Galactic Nuclei jet fossil particles ejected from the central Narrow Angle Tail radio galaxy. New upcoming broad-band VLA X- and Ku-bands data will clarify this. Finally, we conclude that high-frequency, high-sensitive, spectropolarimetric radio data should be explored further, as they can effectively trace shock fronts and thereby provide insights into the intrinsic magneto-ionic properties of radio components.

Tidal features provide signatures of recent galaxy mergers, offering insights into the role of mergers in galaxy evolution. The Vera C. Rubin Observatory's upcoming Legacy Survey of Space and Time (LSST) will allow for an unprecedented study of tidal features around millions of galaxies. We use mock images of galaxies at $z\sim0$ ($z\sim0.2$ for \textsc{NewHorizon}) from \textsc{NewHorizon}, \textsc{eagle}, \textsc{IllustrisTNG}, and \textsc{Magneticum Pathfinder} simulations to predict the properties of tidal features in LSST-like images. We find that tidal features are more prevalent around blue galaxies with intrinsic colours $(g-i)\leq0.5$, compared to redder ones, at fixed stellar mass. This trend correlates with elevated specific star formation rates ($\mathrm{sSFR}>10^{-10}\mathrm{\:yr}^{-1}$), suggesting that merger-induced star formation contributes to the bluer colours. Tidal feature hosts in the red sequence appear to exhibit colour profiles offset to bluer colours for galaxies with stellar masses $10^{10}<M_{\star\mathrm{,\:30\:pkpc}}/\mathrm{M}_\odot<10^{11}$, similarly blue cloud tidal feature host galaxies appear to have their colour profiles offset to bluer colours for $10^{9.5}<M_{\star\mathrm{,\:30\:pkpc}}/\mathrm{M}_\odot<10^{10.5}$. However, the differences in colour profiles in either the red sequence or the blue cloud are not statistically robust and larger samples are needed to test if these differences are real. The predictions across the simulations are quantitatively distinct; therefore, LSST observations will allow us to further constrain the differences between different subgrid physics models.

Stellar and planetary magnetic fields play a crucial role in the habitability of a planet and the integrity of its atmosphere. The recently claimed detection of biosignatures, methane, carbon dioxide and dimethyl sulfide/disulfide, in the atmosphere of K2-18 b, a sub-Neptune orbiting an M dwarf star present an intriguing question regarding the stellar magnetic environment and the resistance of the planet's magnetosphere (if it exists) to erosion by magnetic activity from the host. To probe for radio emission from the system, we have conducted observations using the Karl G. Jansky Very Large Array (VLA) at S, C and X-bands (2-4, 4.5-7.5 and 8-10 GHz respectively) to search for coherent and incoherent radio emission. We detect no radio emission associated with incoherent emission mechanisms. We report $3\sigma$ Stokes I upper limits of $49.8\ \mu\rm{Jybeam}^{-1}$ at S-band, $17.7\ \mu\rm{Jybeam}^{-1}$at C-band and $18.0\ \mu\rm{Jybeam}^{-1}$ at X-band and an upper limit of the ratio of the radio to the total bolometric luminosity of $\log L_\text{R}/\log L_\text{bol}<-8.8$. We have also searched for short duration bursts associated with coherent emission mechanisms at C and X-bands . No signals above a $3\sigma$ significance threshold are detected. Although no signals are detected our radio observations offer constraints, albeit limited, on the stellar magnetic environment supporting recent X-ray observations indicating K2-18 is a very faint emitter. Our results also contextualise any planetary transmission spectra by providing constraints on the activity level of the host.

We apply variational autoencoders to automatically discover galaxy populations using publicly available high-redshift \textit{JWST} spectra without prior classification knowledge. Our unsupervised method identifies distinct astrophysical classes of unique and exciting galaxy types, demonstrating automated discovery capabilities for large spectroscopic surveys.

Bayesian inference is central to modern cosmology. While parameter estimation is achievable with unnormalised posteriors traditionally obtained via MCMC methods, comprehensive model comparison and tension quantification require Bayesian evidences and normalised posteriors, which remain computationally prohibitive for many researchers. To address this, we present $\texttt{unimpeded}$, a publicly available Python library and data repository providing DiRAC-funded (DP192 and 264) pre-computed nested sampling and MCMC chains with their normalised posterior samples, computed using $\texttt{Cobaya}$ and the Boltzmann solver $\texttt{CAMB}$. $\texttt{unimpeded}$ delivers systematic analysis across a grid of eight cosmological models (including $\Lambda$CDM and seven extensions) and 39 modern cosmological datasets (comprising individual probes and their pairwise combinations). The built-in tension statistics calculator enables rapid computation of six tension quantification metrics. All chains are hosted on Zenodo with permanent access via the unimpeded API, analogous to the renowned Planck Legacy Archive but utilising nested sampling in addition to traditional MCMC methods.

Several gamma ray bursts have recently been associated with a kilonova emission. We study the mechanisms which could account for this effect, by means of radioactive decay of elements synthesized in accretion disk wind. We model the r-process nucleosynthesis in the accretion disk wind system, asscociated with the prompt GRB phase. We compute the time-dependent GR MHD evolution of a GRB central engine where the newly formed black hole is accreting the mass from post-merger remnant. We explore the wind properties, for a range of the initial parameters of the system, and study representative cases for compact binary merger progenitors. We compute a suite of 2D and 3D time-dependent General Relativistic numerical simulations with a tabulated 3-parameter equation of state that allows for evolution of chemical composition evolution of the accretion flow. The neutrino emission is accounted for by incorporating the leakage scheme, where neutrino optical depth is calculated along the radial rays. We parameterize the optically thick and thin tori with different values of the pressure maximum and entropy in the disk, while the strength of large-scale poloidal magnetic fields is parameterized according to the chosen gas-to-magnetic pressure ratio. To probe the winds, we follow the particle trajectories. Upon this, we derive the nucleosynthetic yields of heavy elements in the outflows, and we map the regions of Lanthanide rich and poor ejecta. We find that the outflow carries high mass of neutron rich material expanding with mildly relativistic velocities. Our accretion disks operating under the SANE mode can power the GRB jets via neutrino annihilation, if the disk to BH mass ratio is larger than about 0.01 and the black hole is spinning. Slowly spinning black holes surrounded by massive post-merger disks can power these jets, and also be the sites of efficient nucleosynthesis of Lanthanides.

We revisit the stochastic, or noise, contributions to the galaxy density field within the effective field theory (EFT) of large-scale structure. Starting from the general, all-order expression of the EFT partition function, we elucidate how the stochastic contributions can be described by local nonlinear couplings of a single Gaussian noise field. We introduce an alternative formulation of the partition function in terms of such a noise field, and derive the corresponding field-level likelihood for biased tracers. This noise-field formulation can capture the complete set of stochastic contributions to the galaxy density at the field level in a normalized, positive-definite probability density which is suitable for numerical sampling. We illustrate this by presenting the first results of EFT-based field-level inference with non-Gaussian and density-dependent stochasticity on dark matter halos using LEFTfield.

The James Webb Space Telescope (JWST) has discovered numerous bright galaxies at high redshifts ($z\approx$ 10 -- 14). Many astrophysical models and beyond the Standard Model physics scenarios have been proposed to explain these observations. We investigate, for the first time, the implications of dark matter (DM) scattering with baryons (protons and electrons) in light of the JWST UV luminosity function (UVLF) observations. These interactions suppress structure formation on galactic scales, which may have an observable effect on the UVLF measurements at high redshifts. Using a recent galaxy formation model designed to explain high-redshift observations, we obtain strong upper limits on DM-baryon scattering cross-sections and explore new regions of the parameter space. For DM-proton scattering with cross-section $\propto v^{-2}$ velocity dependence, we obtain the strongest limit for DM masses of $\sim$ 1 -- 500 MeV. For other cases that we study (DM-proton scattering cross-section $\propto v^{0},\,v^{-4}$, and DM-electron scattering cross-section $\propto v^{0},\,v^{-2},\,v^{-4}$), our limits are competitive with those obtained from other cosmological observables. Our study highlights the potential of JWST observations as a novel and powerful probe of non-gravitational interactions of DM.

This paper presents an in-depth analysis of the Vega flight computer, and its corresponding ground station developed by CATS, a company producing open-source flight computers and tracking systems tailored for student-made rockets. These flight computers, designed to support rockets reaching altitudes of up to 30 km and possibly higher, play a crucial role in advancing educational rocketry and facilitating hands-on learning experiences in aerospace engineering. As the official sponsor of the European Rocketry Challenge (EuRoC), these flight computers have become integral to the competition, providing reliable and sophisticated telemetry and control capabilities that enhance both safety and performance. The paper delves into the technical specifications and educational impact of these systems, highlighting their contribution to the broader European rocketry programmes. Through comprehensive field data and case studies from the recent European Rocketry Challenge, this study underscores the potential of open-source flight computers to inspire the next generation of aerospace professionals.

In this short note we analyze the inflationary dynamics in Weyl-invariant Einstein-Cartan gravity coupled to the Standard Model of particle physics. We take the axion-like particle of gravitational origin to be approximately massless in the early Universe and show how inflation with the Higgs field materializes.

There is an increasing interest in the community for the Neutron Stars and what we can learn from them. In this review we show how chiral effective field theory, combined with many-body methods, can provide important results that connect Neutron Star properties at zero temperature to nuclear physics and allows to use these compact objects as laboratories of new physics.

Cosmological determinations of the number of relativistic neutrino species, $N^{ }_{\rm eff}$, are becoming increasingly accurate, and further improvements are expected both from CMB and BBN data. Given this context, we update the evaluation of $N^{ }_{\rm eff}$ and the current entropy density via the momentum-averaged approach. This allows for a numerically fast description of neutrino decoupling, easily portable to an array of new physics scenarios. We revisit all aspects of this approach, including collision terms with full electron mass dependence, finite temperature QED corrections to the equation of state, neutrino oscillations, and the modelling of neutrino ensembles with effective chemical potentials. For integrated observables, our results differ by less than $0.04\%$ from the solution of the momentum-dependent evolution equation. We outline how to extend the approach to BSM settings, and will highlight its power in Part II. To facilitate the practical implementation, we release a Mathematica and Python code within nudec_BSM_v2, easily linkable to BBN codes.

Low mass particles with small electric charges can be produced abundantly in large electric fields via the Schwinger effect. We study the production rate of such particles inside the polar gap of nearby pulsars. After production they are accelerated above MeV energies by the local electric fields. These pulsar-produced millicharged particles can be detected at Earth in low-threshold dark matter direct detection experiments. We find that the current XENONnT data constrains millicharged particles produced in the Crab pulsar to have charges less than $O(10^{-6})$ for sub-eV masses.

Primordial Black Holes (PBHs) represent one of the more interesting ways to address dark matter, at the interface of both cosmology and quantum gravity. It is no surprise then that testing PBHs is a venue of active interest, with several cosmological and astrophysical probes constraining different mass ranges. In this work, we propose novel Solar System scale searches for PBHs, motivated by the unique precision and coverage of local observables. We show that asteroid to dwarf planet mass PBHs can induce measurable dipolar timing signatures in pulsar timing arrays, while planetary mass PBHs can generate detectable ADAF accretion flares through interactions with Kuiper Belt bodies. Together, these complementary approaches open a new observational frontier for probing PBHs across mass ranges that remain unconstrained by conventional cosmological methods.

We investigate dark matter (DM) phenomenology and cosmic inflation within a unified framework based on a dark $U(1)_D$ gauge extension of the Standard Model (SM). The associated dark gauge boson, namely the dark photon, serves as a viable DM candidate, which we call dark photon dark matter (DPDM), whilst the dark Higgs field drives inflation. We explore a low-reheating scenario where DM production occurs during reheating, resulting in significant entropy dilution of the DPDM abundance. Both weakly interacting massive particle (WIMP) and feebly interacting massive particle (FIMP) DM scenarios are explored, depending on the dark gauge coupling strength. For FIMP-type DM, the entropy dilution allows for stronger couplings whilst maintaining the correct relic abundance, potentially bringing these candidates within the reach of current and near-future detection experiments. Similarly, WIMP-type DM can be realised with weaker couplings. We perform a comprehensive parameter scan incorporating constraints from collider data, DM direct and indirect detection experiments, and cosmological observations. Taking quantum corrections and running of the couplings into account, we demonstrate that dark Higgs inflation yields predictions for the spectral index $n_s$ and the tensor-to-scalar ratio $r$ that are consistent with the Planck, BICEP/Keck, and ACT data. The nonminimal coupling of the dark Higgs inflaton field to gravity is shown to be much smaller than in the case of the SM Higgs inflation scenario, avoiding unitarity concerns. We show that reheating temperatures as low as 1 GeV and 1 MeV can be achieved through the decay and scattering processes of the inflaton, respectively, with the latter allowing for larger Higgs mixing angles and enhanced detection prospects. Our results establish that this minimal extension successfully unifies DM physics with inflationary cosmology.

We present a non-perturbative framework for the dynamics of slow-roll inflation that consistently incorporates quantum corrections, based on an alternative functional renormalisation group (RG) approach. We derive the coupled Friedmann-RG flow equations governing the joint evolution of spacetime, the inflaton field, and its effective potential. Applying this formalism to $\alpha$-attractor E-models, we find that the RG flow induces a dynamical destabilisation of the inflationary trajectory, leading to a premature termination of slow roll. Remarkably, the resulting predictions bring $\alpha$-attractors into full agreement with the latest ACT data without introducing new physics beyond a consistent quantum-corrected treatment of the inflaton dynamics.

We propose a resolution to the longstanding problem of perturbative normalizability in canonical quantum gravity of the Lorentzian Chern-Simons-Kodama (CSK) state with a positive cosmological constant in four dimensions. While the CSK state is an exact solution to the Hamiltonian constraint in the self-dual formulation and semiclassically describes de Sitter spacetime, its physical viability has been questioned due to apparent nonnormalizability and CPT asymmetry. Starting from a nonperturbative holomorphic inner product derived from the reality conditions of the self-dual Ashtekar variables, we show that the linearization, in terms of gravitons, of the CSK state is perturbatively normalizable for super-Planckian cosmological constant. Furthermore, we demonstrate that a rotation in phase space, a generalization of Thiemann's complexifier, can render the full perturbative state normalizable for all $\Lambda$ by analytically continuing the non-convergent modes in phase space. This provides the first concrete realization of a CPT-breaking, yet normalizable, gravitational vacuum state rooted in a nonperturbative quantum gravity framework. Our results establish the CSK state-long thought formal-as a viable candidate for the ground state of quantum gravity in de Sitter space.