Papers for Monday, Sep 26 2022

Dark matter is the dominant form of matter in today's universe. Its gravitational effects drive the formation of galaxies and all larger structure, yet its nature is unknown. As gravitational collapse creates the first cosmic objects, a dark matter cusp forms immediately at every initial density maximum. Such prompt cusps have a density profile $\rho\propto r^{-1.5}$ extending up to a limiting density dependent on the nature of the dark matter. Numerical simulations and theoretical arguments suggest that the bulk of these cusps survive until the present day. Here we show that if dark matter is a thermally produced weakly interacting massive particle, many thousands of prompt cusps with individual masses similar to that of the earth should be present in every solar mass of dark matter. This radically alters predictions for the amount and spatial distribution of dark matter annihilation radiation, substantially tightening observational constraints on the relevant cross sections. In particular, the cross section required to explain the observed $\gamma$-ray excess near the Galactic Centre predicts prompt cusp emission from the Milky Way's outer halo and from extragalactic dark matter at levels in tension with the observed diffuse $\gamma$-ray background.

With Cosmicflows-4, distances are compiled for 55,877 galaxies gathered into 38,065 groups. Eight methodologies are employed, with the largest numbers coming from the correlations between the photometric and kinematic properties of spiral galaxies (TF) and elliptical galaxies (FP). Supernovae that arise from degenerate progenitors (SNIa) are an important overlapping component. Smaller contributions come from distance estimates from the surface brightness fluctuations of elliptical galaxies (SBF) and the luminosities and expansion rates of core collapse supernovae (SNII). Cepheid Period-Luminosity Relation (CPLR) and Tip of the Red Giant Branch (TRGB) observations founded on local stellar parallax measurements along with the geometric maser distance to NGC 4258 provide the absolute scaling of distances. The assembly of galaxies into groups is an important feature of the study in facilitating overlaps between methodologies. Merging between multiple contributions within a methodology and between methodologies is carried out with Bayesian Markov chain Monte Carlo procedures. The final assembly of distances is compatible with a value of the Hubble constant of $H_0=75.0$ km s$^{-1}$ Mpc$^{-1}$ with the small statistical error $\pm$ $0.8$ km s$^{-1}$ Mpc$^{-1}$ but a large potential systematic error ~3 km s$^{-1}$ Mpc$^{-1}$. Peculiar velocities can be inferred from the measured distances. The interpretation of the field of peculiar velocities is complex because of large errors on individual components and invites analyses beyond the scope of this study.

There is evidence that some red supergiants (RSGs) experience short lived phases of extreme mass loss, producing copious amounts of dust. These episodic outburst phases help to strip the hydrogen envelope of evolved massive stars, drastically affecting their evolution. However, to date, the observational data of episodic mass loss is limited. This paper aims to derive surface properties of a spectroscopic sample of fourteen dusty sources in the Magellanic Clouds using the Baade telescope. These properties may be used for future spectral energy distribution fitting studies to measure the mass loss rates from present circumstellar dust expelled from the star through outbursts. We apply MARCS models to obtain the effective temperature ($T_{\rm eff}$) and extinction ($A_V$) from the optical TiO bands. We use a $\chi^2$ routine to determine the best fit model to the obtained spectra. We compute the $T_{\rm eff}$ using empirical photometric relations and compare this to our modelled $T_{\rm eff}$. We have identified a new yellow supergiant and spectroscopically confirmed eight new RSGs and one bright giant in the Magellanic Clouds. Additionally, we observed a supergiant B[e] star and found that the spectral type has changed compared to previous classifications, confirming that the spectral type is variable over decades. For the RSGs, we obtained the surface and global properties, as well as the extinction $A_V$. Our method has picked up eight new, luminous RSGs. Despite selecting dusty RSGs, we find values for $A_V$ that are not as high as expected given the circumstellar extinction of these evolved stars. The most remarkable object from the sample, LMC3, is an extremely massive and luminous evolved massive star and may be grouped amongst the largest and most luminous RSGs known in the Large Magellanic Cloud (log(L$_*$/L$_{\odot})\sim$5.5 and $R = 1400 \,\ \textrm R_{\odot}$).

The process of galactic disc growing is still not fully understood. In the majority of disk galaxies the gas and stars are located in the same plane and rotate in the same direction. However, there are kinematically peculiar galaxies hosting two counter-rotating stellar discs. Their origin is believed to be the result of a past event of accretion of gas followed by star formation. By studying such galaxies we can learn how much material, when, and how, have fallen onto the progenitor galaxy. We identified a sample of 56 counter-rotating galaxies in the MaNGA IFU survey and initiated a follow-up observing campaign at the 6-m telescope (BTA) aiming to determine the stellar population properties of both stellar discs. Our preliminary results suggest the dichotomy of the sample of counter-rotating galaxies. We found that most massive galaxies have extended counter-rotating disks, whose contribution to luminosity is higher than in the less massive galaxies suggestive of different evolutionary paths.

Shape measurements of galaxies and galaxy clusters are widespread in the analysis of cosmological simulations. But the limitations of those measurements have been poorly investigated. In this paper, we explain why the quality of the shape measurement does not only depend on the numerical resolution, but also on the density gradient. In particular, this can limit the quality of measurements in the central regions of haloes. We propose a criterion to estimate the sensitivity of the measured shapes based on the density gradient of the halo and apply it to cosmological simulations of collisionless and self-interacting dark matter. By this, we demonstrate where reliable measurements of the halo shape are possible and how cored density profiles limit their applicability.

We develop a new analysis method that allows us to compare multi-dimensional observables to a theoretical model. The method is based on unsupervised clustering algorithms which assign the observational and simulated data to clusters in high dimensionality. From the clustering result, a goodness of fit (the p-value) is determined with the Fisher-Freeman-Halton test. We first show that this approach is robust for 2D Gaussian distributions. We then apply the method to the observed MW satellites and simulated satellites from the fiducial model of our semi-analytic code A-SLOTH. We use the following 5 observables of the galaxies in the analysis: stellar mass, virial mass, heliocentric distance, mean stellar metallicity [Fe/H], and stellar metallicity dispersion {\sigma}[Fe/H]. A low p-value returned from the analysis tells us that our A-SLOTH fiducial model does not reproduce the mean stellar metallicity of the observed MW satellites well. We implement an ad-hoc improvement to the physical model and show that the number of dark matter merger trees which have p-values > 0.01 increases from 3 to 6. This method can be extended to data with higher dimensionality easily. We plan to further improve the physical model in A-SLOTH using this method to study elemental abundances of stars in the observed MW satellites.

Most local massive galaxies, if not all, are believed to harbor a supermassive black hole (SMBH) at the center. Galaxy mergers have long been thought to drive strong gas inflows and accretion onto one or both central SMBH, triggering single or dual quasars as a natural stage of the hierarchical galaxy and SMBH evolution. While many dual active galactic nuclei -- the low-luminosity counterparts of quasars -- have been observed at low redshift, no unambiguous dual quasar is known at cosmic noon (z>~2) when both quasar activity and global star formation density peaked. While a handful of dual quasar candidates were known at z>1, competing explanations remained. Here we report multi-wavelength observations of SDSS J0749+2255 as the first kpc-scale dual quasar confirmed to be hosted by a galaxy merger at cosmic noon. Hubble Space Telescope NIR imaging reveals extended host galaxies underlying the compact double nuclei (separated by 0.46" or 3.8 kpc) and tidal features as evidence for galactic interactions. We also present new multi-wavelength observations, all lending support to the dual quasar hypothesis. Unlike the low-redshift low-luminosity counterparts, the high-redshift dual quasar is hosted by two massive compact disk-dominated galaxies, which may be critical for efficient gas fueling onto the SMBHs in the early-stage merger. The apparent lack of stellar bulges and that SDSS J0749+2255 already follows the local SMBH mass-host stellar mass relation are at odds with the canonical SMBH-host co-evolution picture and suggest that at least some SMBHs may have formed before their host stellar bulges. While still at kpc-scale separations where the host-galaxy gravitational potential dominates, the SMBHs may evolve into a gravitationally bound binary system in ~0.22 Gyr. The merger products at low redshift are expected to be gravitational wave sources for pulsar-timing arrays (abridged).

Despite significant efforts in the recent years, the physical processes responsible for the formation of passive galaxies through cosmic time remain unclear. The shape and evolution of the Stellar Mass Function (SMF) give an insight into these mechanisms. Taking advantage from the CANDELS and the deep Hubble Frontier Fields (HFF) programs, we estimated the SMF of total, star-forming and passive galaxies from z=0.25 to z=2.75 to unprecedented depth, and focus on the latter population. The density of passive galaxies underwent a significant evolution over the last 11 Gyr. They account for 60% of the total mass in the nearby Universe against ~20% observed at z~2.5. The inclusion of the HFF program allows us to detect, for the first time at z>1.5, the characteristic upturn in the SMF of passive galaxies at low masses, usually associated with environmental quenching. We observe two separate populations of passive galaxies evolving on different timescales: roughly half of the high mass systems were already quenched at high redshift, while low mass passive galaxies are gradually building-up over the redshift range probed. In the framework of environmental-quenching at low masses, we interpret this finding as evidence of an increasing role of the environment in the build-up of passive galaxies as a function of time. Finally, we compared our findings with a set of theoretical predictions. Despite good agreement in some redshift and mass intervals, none of the models are able to fully reproduce the observations. This calls for further investigation into the involved physical mechanisms, both theoretically and observationally, especially with the brand new JWST data.

We present time-series CCD photometry in the $BVRI$ passbands of the recently identified symbiotic nova V1835 Aquilae (NSV 11749) over an interval of 5.1 years with 7-14 day cadence, observed during its quiescence. We find slow light variations with a range of $\sim$0.9 mag in $V$ and $\sim$0.3 mag in $I$. Analysis of these data show strong periodicity at $419 \pm 10$ days, which we interpret to be the system's orbital period. A dip in the otherwise-sinusoidal phased light curve suggests a weak ellipsoidal effect due to tidal distortion of the giant star, which in turn opens the possibility that V1835 Aql transfers some of its mass to the hot component via Roche lobe overflow rather than via a stellar wind. We also find evidence that V1835 Aql is an S-type symbiotic star, relatively free of circumstellar dust, and include it among the nuclear burning group of symbiotics. Finally, we provide photometry, periods, and light curve classifications for 22 variable stars in the field around V1835 Aql, about half of which are newly identified.

Meteoroids impacting the Earth on a daily basis are fragments of asteroids and comets. By studying fireballs produced during their disintegration in the atmosphere, we can gain information about their source regions and the properties of their parent bodies. In this work, data on 824 fireballs presented in an accompanying paper and catalog are used. We propose a new empirical parameter for the classification of the physical properties of meteoroids, based on the maximum dynamic pressure suffered by the meteoroid in the atmosphere. We then compare the physical and orbital properties of meteoroids. We find that aphelion distance is a better indicator of asteroidal origin than the Tisserand parameter. Meteoroids with aphelia lower than 4.9 AU are mostly asteroidal, with the exception of the Taurids and alpha Capricornids associated with the comets 2P/Encke and 169P/NEAT, respectively. We found another population of strong meteoroids of probably asteroidal origin on orbits with either high eccentricities or high inclinations, and aphelia up to ~ 7 AU. Among the meteoroid streams, the Geminids and eta Virginids are the strongest, and Leonids and alpha Capricornids the weakest. We found fine orbital structures within the Geminid and Perseid streams. Four minor meteoroid streams from the working list of the International Astronomical Union were confirmed. No meteoroid with perihelion distance lower than 0.07 AU was detected. Spectra are available for some of the fireballs, and they enabled us to identify several iron meteoroids and meteoroids deficient in sodium. Recognition and frequency of fireballs leading to meteorite falls is also discussed.

We present a magnetic activity study of GJ 436 using spectroscopic data from HARPS, spanning over 14 years, and additional data from NARVAL, falling within the HARPS observations. We study the CaII H&K, HeID3, NaI doublet, H$\alpha$ and CaII IRT triplets lines and explore linear correlations between them. Using the full HARPS dataset, we found indices H$\alpha$ vs CaII H&K & H$\alpha$ vs HeI to correlate positively. From the NARVAL dataset, covering one observing epoch, we found CaII IRT$_{3}$ vs CaII IRT$_{2}$ & CaII IRT$_{3}$ vs H$\alpha$ index to correlate negatively. We investigate long and short-term periodicity in these index variations using the Generalised Lomb-Scargle periodogram. For CaII H&K, NaI and H$\alpha$ indices, we detect long-term periods of 2470.7d (~ 6.8 years), 1861.6d (~ 5.1 years) and 2160.9d (~ 5.9 years) respectively, consistent with GJ 436's photometric cycle of ~ 7.4 years. Applying the "Pooled Variance" technique to H$\alpha$ & NaI indices, we found ~ 2500d to be the period of an activity cycle mechanism, in good agreement with the detected 2470.7d period. For CaII H&K and H$\alpha$ indices, we detect short-term periods of $39.47^{+0.11}_{-0.15}$d and $40.46^{+0.44}_{-0.52}$d respectively, identified as the stellar rotation period. The stellar rotation is detected after prewhitening the long-term periodicity. It is detected as well in the analysis of individual observing epochs.

When performing cosmological inference, standard analyses of the Lyman-$\alpha$ (Ly$\alpha$) three-dimensional correlation functions only consider the information carried by the distinct peak produced by baryon acoustic oscillations (BAO). In this work, we address whether this compression is sufficient to capture all the relevant cosmological information carried by these functions. We do this by performing a direct fit to the full shape, including all physical scales without compression, of synthetic Ly$\alpha$ auto-correlation functions and cross-correlations with quasars at effective redshift $z_{\rm{eff}}=2.3$, assuming a DESI-like survey, and providing a comparison to the classic method applied to the same dataset. Our approach leads to a $3.5\%$ constraint on the matter density $\Omega_{\rm{M}}$, which is about three to four times better than what BAO alone can probe. The growth term $f \sigma_{8} (z_{\rm{eff}})$ is constrained to the $10\%$ level, and the spectral index $n_{\rm{s}}$ to $\sim 3-4\%$. We demonstrate that the extra information resulting from our `direct fit' approach, except for the $n_{\rm{s}}$ constraint, can be traced back to the Alcock-Paczy\'nski effect and redshift space distortion information.

Chemistry in Titan's N2-CH4 atmosphere produces complex organic aerosols. The chemical processes and the resulting organic compounds are still far from understood, although extensive observations, laboratory, and theoretical simulations have greatly improved physical and chemical constraints on Titan's atmosphere. Here, we conduct a series of Titan atmosphere simulation experiments with N2-CH4 gas mixtures and investigate the effect of initial CH4 ratio, pressure, and flow rate on the production rates and composition of the gas and solid products at a Titan relevant temperature (100 K) for the first time. We find that the production rate of the gas and solid products increases with increasing CH4 ratio. The nitrogen-containing species have much higher yield than hydrocarbons in the gas products, and the N-to-C ratio of the solid products appears to be the highest compared to previous plasma simulations with the same CH4 ratio. The greater degree of nitrogen incorporation in the low temperature simulation experiments suggests temperature may play an important role in nitrogen incorporation in Titan's cold atmosphere. We also find that H2 is the dominant gas product and serves as an indicator of the production rate of new organic molecules in the experiment, and that CH2NH may greatly contribute to the incorporation of both carbon and nitrogen into the solid particles. The pressure and flow rate affect the amount of time of the gas mixture exposed to the energy source and therefore impact the N2-CH4 chemistry initiated by the plasma discharge, emphasizing the influence of the energy flux in Titan atmospheric chemistry.

Post-flare arcades are well-known components of solar flare evolution, which have been observed for several decades. Coronal rain, cascades of catastrophically-cooled plasma, outline the loops and provide eye-catching evidence of the recent flare. These events are acknowledged to be common, but the scientific literature does not include any statistical overview documenting just how common the phenomenon actually is. This study reviews Solar Dynamics Observatory Atmospheric Imaging Assembly (SDO AIA) observations of 241 flares collected from the Space Weather Prediction Center (SWPC) database between 2011 and 2018. The flares cover the entire strength range of the C, M, and X GOES classes, and are distributed evenly across the SDO-observed majority of Solar Cycle 24. We find that post-flare arcade rain occurs for nearly all X and most M-class flares, but that it tapers off rapidly within C-class flares. There appears to be a cut-off point around C5, below which the occurrence of post-flare arcade rain drops significantly. There is also a general positive correlation between GOES class and the average duration of post-flare rain events. Post-flare arcade rain events in C-class flares appear to track with the sunspot number, providing a potential new tool for estimating, if not predicting, solar cycle strength. Furthermore, condensations appear to be suppressed in the shortest-length arcade loops of any class observed, suggesting that active region heating is height-constrained. These results open up further avenues for future research, including new methods to estimate energy deposition and to gain greater insight into steady active region heating.

Recent work published by Lindsey et al find evidence for a deep and compact seismic source for the sunquake associated with the 2011 July 30 M9.3 flare, as well as seismic emission extending up to 10 mHz. We examine the sunquake independently, and a possible wavefront is found in the 8 mHz band, though no wavefront is easily discernible in the 10 mHz band. Additionally, we perform numerical simulations of seismic excitation modeled with the reported parameters and changes in the power spectra with increasing depth of the excitation source are examined. It is found that the peak frequency decreases for increasing depths, but a shallow minimum is indicated between z=0 and z=-840 km. Analysis of the suspected wavefront of the M9.3 sunquake finds that the power spectrum of the reported seismic emission is close to that of background oscillations, though with a peak frequency noticeably lower than the background peak. Additionally, it is found that the amplitude of the source estimated by Lindsey et al is too low to produce the observed wavefront.

JWST will be able to observe the atmospheres of rocky planets transiting nearby M dwarfs. The M dwarf triple star system LTT 1445, at a distance of 6.86 pc, hosts some of the nearest rocky terrestrial planets. These planets most likely orbit the M 3.5V star LTT 1445A. During a 28.6 ksec Chandra ACIS-S3 observation we have i) spatially resolved and detected all three stars in the LTT 1445 system, ii) measured the X-ray luminosity of the individual stars, including LTT 1445A, for the first time, iii) studied the flux variability of the X-ray sources and found strong variability from the A and C components, and iv) investigated how the coronal luminosities, temperatures and volume emission measures vary at different activity levels. Combining these X-ray data with upcoming HST ultraviolet observations will allow a differential emission measure (DEM) estimation of the star's EUV spectrum, thereby facilitating modeling of the rocky planets' atmospheres.

The COSMOS field has been extensively observed by most major telescopes, including Chandra, HST, and Subaru. HST imaging boasts very high spatial resolution and is used extensively in morphological studies of distant galaxies. Subaru provides lower spatial resolution imaging than HST but a substantially wider field of view with greater sensitivity. Both telescopes provide near-infrared imaging of COSMOS. Successful morphological fitting of Subaru data would allow us to measure morphologies of over $10^4$ known active galactic nucleus (AGN) hosts, accessible through Subaru wide-field surveys, currently not covered by HST. For 4016 AGN between $0.03<z<6.5$, we study the morphology of their galaxy hosts using GALFIT, fitting components representing the AGN and host galaxy simultaneously using the i-band imaging from both HST and Subaru. Comparing the fits for the differing telescope spatial resolutions and image signal-to-noise ratios, we identify parameter regimes for which there is strong disagreement between distributions of fitted parameters for HST and Subaru. In particular, the S\'ersic index values strongly disagree between the two sets of data, including sources at lower redshifts. In contrast, the measured magnitude and radius parameters show reasonable agreement. Additionally, large variations in the S\'ersic index have little effect on the $\chi^2_\nu$ of each fit whereas variations in other parameters have a more significant effect. These results indicate that the S\'ersic index distributions of high-redshift galaxies that host AGN imaged at ground-based spatial resolution are not reliable indicators of galaxy type, and should be interpreted with caution.

We present evolutionary pathways for creating hot subdwarf OB (sdOB) stars from hierarchical triple configurations. We use the population synthesis code Multiple Stellar Evolution (MSE) to follow the stellar, binary, and gravitational dynamical evolution of triple-star systems. To ascertain the effect of the outer tertiary, we also consider the evolution of the inner binary with the tertiary component removed. We find we are able to create sdOB stars in single, binary and triple configurations. We also demonstrate that it is possible to form sdOBs in systems which undergo triple common envelope evolution, when the tertiary star undergoes unstable mass transfer onto the inner binary. We are unable to create single or wide sdOB systems without involving a merger earlier in the evolution. The triples can produce sdOBs in binaries with wide, non-interacting companions through binary interactions, which is impossible in isolated binaries. Owing to the closeness of the inner binary in hierarchical triples the formation channels associated with stable mass transfer are suppressed when compared to the isolated binary case.

Ice cores are known to yield information about astronomical phenomena as well as information about past climate. We report time series analyses of annually resolved nitrate variations in an ice core, drilled at the Dome Fuji station in East Antarctica, corresponding to the period from CE 1610 to 1904. Our analyses revealed clear evidence of ~11, ~22, and ~90 year periodicities, comparable to the respective periodicities of the well-known Schwabe, Hale, and Gleissberg solar cycles. Our results show for the first time that nitrate concentrations in an ice core can be used as a proxy for past solar activity on decadal to multidecadal time scales. Furthermore, 11-year and 22-year periodicities were detected in nitrate variations even during the Maunder Minimum (1645-1715), when sunspots were almost absent. This discovery may support cyclic behavior of the solar dynamo during the grand solar minimum.

We combine photometric metallicities with astrometry from Gaia DR3 to examine the chemodynamic structure of ~280,000 K dwarfs in the Solar Neighborhood (SN). In kinematics, we observe ridges/clumps of "kinematic groups", like studies of more massive main-sequence stars. Here we note clear differences in both metallicity and vertical velocity as compared to the surrounding regions in velocity space and hypothesize this is due to differences in mean age. To test this, we develop a method to estimate the age distribution of sub-populations of stars. In this method, we use GALAH data to define probability distributions of W vs. [M/H] in age bins of 2 Gyr and determine optimal age distributions as the best fit weighted sum of these distributions. This process is then validated using the GALAH subset. We estimate the probable age distribution for regions in the kinematic plane, where we significant sub-structure that is correlated with the kinematic groups. Most notably, we find an age gradient across the Hercules streams that is correlated with birth radius. Finally, we examine the bending and breathing modes in the kinematic plane and find correlations with age, where the breathing amplitude decrease with age and the bending amplitude is constant, except for a large increase for stars of 10-12 Gyr. This is one of the first studies to examine these chemodynamics in the SN using primarily low-mass stars and we hope these findings can better constrain dynamical models of the Milky Way due to the increase in resolution the sample size provides.

We present a catalog (status July 1, 2022) of triple and higher order systems identified containing exoplanets based on data from the literature, including various analyses. We explore statistical properties of the systems with focus on both the stars and the planets. So far, about 30 triple systems and one to three quadruple systems, including (mildly) controversial cases, have been found. The total number of planets is close to 40. All planet-hosting triple star systems are highly hierarchic, consisting of a quasi-binary complemented by a distant stellar component, which is in orbit about the common center of mass. Furthermore, the quadruple systems are in fact pairs of close binaries (``double-doubles"), with one binary harboring a planet. For the different types of star-planet systems, we introduce a template for the classifications of planetary orbital configurations in correspondence to the hierarchy of the system and the planetary host. The data show that almost all stars are main-sequence stars, as expected. However, the stellar primaries tend to be more massive (i.e., corresponding to spectral types A, F, and G) than expected from single star statistics, a finding also valid for stellar secondaries but less pronounced. Tertiary stellar components are almost exclusively low-mass stars of spectral type M. Almost all planets have been discovered based on either the Radial Velocity or the Transit method. Both gas giants (the dominant type) and terrestrial planets (including super-Earths) have been identified. We anticipate the expansion of this data base in the light of future planetary search missions.

In this paper we use a Soft-Sphere Discrete Element method code to simulate the transmission and study the attenuation of a seismic wave. Then, we apply our findings to the different space missions that have had to touch the surface of different small bodies. Additionally, we do the same in regards to the seismic wave generated by the hypervelocity impacts produced by the DART and Hayabusa2 missions once the shock wave transforms into a seismic wave. We find that even at very low pressures, such as those present in the interior of asteroids, the seismic wave speed can still be on the order of hundreds of m/s depending on the velocity of the impact that produces the wave. As expected from experimental measurements, our results show that wave velocity is directly dependent on $P^{1/6}$, where $P$ is the total pressure (confining pressure plus wave induced pressure). Regardless of the pressure of the system and the velocity of the impact (in the investigated range), energy dissipation is extremely high. These results provide us with a way to anticipate the extent to which a seismic wave could have been capable of moving some small particles on the surface of a small body upon contact with a spacecraft. Additionally, this rapid energy dissipation would imply that even hypervelocity impacts should perturb only the external layer of a self-gravitating aggregate on which segregation and other phenomena could take place. This would in turn produce a layered structure of which some evidence has been observed

The origin of pulsar radio emission is one of the old puzzles in theoretical astrophysics. In this Letter we present a global kinetic plasma simulation which shows from first-principles how and where radio emission can be produced in pulsar magnetospheres. We observe the self-consistent formation of electric gaps which periodically ignite electron-positron discharge. The gaps form above the polar-cap, and in the bulk return-current. Discharge of the gaps excites electromagnetic modes which share several features with the radio emission of real pulsars. We also observe the excitation of plasma waves and charge bunches by streaming instabilities in the outer magnetosphere. Our numerical experiment demonstrates that global kinetic models can provide deep insight into the emission physics of pulsars, and may help interpret their multi-wavelength observations.

According to core-accretion formation models, the conditions under which gas giants will form around M dwarfs are very restrictive. Also, the correlation of the occurrence of these planets with the metallicity of host stars is still unknown due to the intrinsic faintness of M dwarfs in the optical and some intricacies in their spectra. Interestingly, NASA's TESS mission has started to create a growing sample of these systems, with ten observed planets located in close-in orbits: contrary to what is expected for low stellar masses. Tidal interactions with the host star will play a key role in determining the fate of these planets, so by using the measured physical and orbital characteristics of these M-dwarf systems we numerically analyse the exchange of rotational and orbital angular momentum, while constraining the energy dissipation in each system to calculate whether host stars are spun up or spun down, depending on the relationship between the gain and loss of angular momentum by the stellar rotation. We also study the coupled orbital and physical evolution of their gas giant companion and calculate orbital circularization time-scales, as well as the time needed to undergo orbital decay from their current orbital position to the Roche limit. The thorough study of tidal processes occurring over short and long time-scales in star-planet systems like those studied here, can help constrain tidal dissipation rates inside the star and planet, complement tidal theories, and improve estimations of unconstrained properties of exoplanetary systems.

Under the coronal magnetic field, we estimate the maximal jet power of the Blandford-\Znajek (BZ) mechanism, Blandford-\Payne (BP) mechanism, and hybrid model. The jet power of the BZ and Hybrid model mechanisms depends on the spin of a black hole, while the jet power of the BP mechanism does not depend on the spin of a black hole. At high black hole spin, the jet power of the hybrid model is greater than that of the BZ and BP mechanisms. We find that the jet power of almost all gamma-\ray narrow line Seyfert 1 galaxies (gamma-\NLS1s) can be explained by the hybrid model. However, one source with jet power 0.1~\1 Eddington luminosity can not be explained by the hybrid model. We suggest that the magnetic field dragged inward by the accretion disk with magnetization-\driven outflows may accelerate the jets in this gamma-\NLS1.

The accretion of matter onto the surface of a neutron star in a low-mass X-ray binary triggers X-ray bursts, whose ashes are buried and further processed thus altering the composition and the properties of the stellar crust. In this second paper of a series, the impact of accretion on the equation of state and on the global properties of neutron stars is studied in the framework of the nuclear energy-density functional theory. Considering ashes made of $^{56}$Fe, we calculated the equations of state using the same Brussels-Montreal nuclear energy-density functionals BSk19, BSk20, and BSk21, as those already employed for determining the crustal heating in our previous study for the same ashes. All regions of accreting neutron stars were treated in a unified and thermodynamically consistent way. With these equations of state, we determined the mass, radius, moment of inertia, and tidal deformability of accreted neutron stars and compared with catalyzed neutron stars for which unified equations of state based on the same functionals are available. The equation of state of accreted neutron stars is found to be significantly stiffer than that of catalyzed matter, with an adiabatic index $\Gamma \approx 4/3$ throughout the crust. For this reason, accreting neutron stars have larger radii. However, their crustal moment of inertia and their tidal deformability are hardly changed provided density discontinuities at the interface between adjacent crustal layers are properly taken into account. The enhancement of the stiffness of the equation of state of accreting neutron stars is mainly a consequence of nuclear shell effects, thus confirming the importance of a quantum treatment as stressed in our first study. With our previous calculations of crustal heating using the same functionals, we have thus obtained consistent microscopic inputs for simulations of accreting neutron stars.

The High Altitude Detection of Astronomical Radiation (HADAR) experiment is a refracting terrestrial telescope array based on the atmospheric Cherenkov imaging technique. It focuses the Cherenkov light emitted by extensive air showers through a large aperture water-lens system for observing very-high-energy-rays and cosmic rays. With the advantages of a large field-of-view (FOV) and low energy threshold, the HADAR experiment operates in a large-scale sky scanning mode to observe galactic sources. This study presents the prospects of using the HADAR experiment for the sky survey of TeV {\gamma}-ray sources from TeVCat and provids a one-year survey of statistical significance. Results from the simulation show that a total of 23 galactic point sources, including five supernova remnant sources and superbubbles, four pulsar wind nebula sources, and 14 unidentified sources, were detected in the HADAR FOV with a significance greater than 5 standard deviations ({\sigma}). The statistical significance for the Crab Nebula during one year of operation reached 346.0 {\sigma} and the one-year integral sensitivity of HADAR above 1TeV was ~1.3%-2.4% of the flux from the Crab Nebula.

Young massive star clusters inhabit regions of star formation and play an essential role in the galactic evolution. They are sources of both thermal and non-thermal radiation, and they are effective cosmic ray accelerators. We present the 3D magnetohydrodynamic (MHD) modeling of the plasma flows in a young compact cluster at the evolutionary stage comprising multiple interacting supersonic winds of massive OB and WR stars. The modeling allows studying the partitioning of the mechanical energy injected by the winds between the bulk motions, thermal heating and magnetic fields. Cluster-scale magnetic fields reaching the magnitudes of $\sim$ 300 $\mu$G show the filamentary structures spreading throughout the cluster core. The filaments with the high magnetic fields are produced by the Axford-Cranfill type effect in the downstream of the wind termination shocks, which is amplified by a compression of the fields with the hot plasma thermal pressure in the central part of the cluster core. The hot ($\sim$ a few keV) plasma is heated at the termination shocks of the stellar winds and compressed in the colliding postshock flows. We also discuss a possible role of the thermal conduction effects on the plasma flow, analyse temperature maps in the cluster core and the diffuse thermal X-ray emission spectra. The presence of high cluster-scale magnetic fields supports the possibility of high-energy cosmic ray acceleration in clusters at the given evolutionary stage.

The possibility that the $H_0$ tension is a sign of a physics beyond the $\Lambda$CDM model is one of the most exciting possibilities in modern cosmology. The challenge of solving this problem is complicated by several factors, including the worsening of the tension on $\sigma_8$ parameter when that on $H_0$ is raised. Furthermore, the perspective from which the problem is viewed should not be underestimated, since the tension on $H_0$ can also be interpreted as a tension on the size of the acoustic horizon, $r_s$, which deserves proper discussion. The common approach in the literature consists in proposing a new model that can resolve the tension and treat the new parameters of the theory as free in the analysis. However, allowing additional parameters to vary often results in larger uncertainties on the inferred cosmological parameters, causing an apparent relaxing in the tension due to the broaden in the posterior, instead of a genuine shift in the central value of $H_{0}$. To avoid this, we consider here an empirical approach that assumes specific non-standard values of the $\Lambda$CDM extensions and we analyze how the important parameters in the context of the tension vary accordingly. For our purposes, we study simple extensions of the standard cosmological model, such as a phantom DE component (with Equation of State $w < 1$) and extra relativistic species in the early Universe (so that $N_{eff} > 3.046$). We obtain relations between variation in the value of $w$ and $N_{eff}$ and changes in $H_0$, $r_s$ and $\sigma_8$. In this way an empirical relation between $H_0$ and $\sigma_8$ is provided, that is a first step in understanding which classes of theoretical models, and with which characteristics, could be able to break the correlation between the two tensions.

We study the giant outbursts of SMC X-3 and RX J0209.6-7427 to compare their super-Eddington accretion regime with that of Swift J0243.6+6124. The high double-peak profile of SMC X-3 is found to be 0.25 phase offset from that below $2.3\times10^{38}$erg\,s$^{-1}$, which is similar to Swift J0243 (happened around $0.9\times10^{38}$erg\,s$^{-1}$). The profile of RX J0209 shows a similar 0.25 phase offset between high double-peak and low double-peak around $1.25\times10^{38}$erg\,s$^{-1}$. The 0.25 phase offset corresponds to a 90 degree angle change of the emission beam and strongly supports for a transition from a fan beam to a pencil beam. Their critical luminosities imply a surface magnetic field $\sim4\times10^{13}$ G and $2\times10^{13}$ G for SMC X-3 and RX J0209, respectively, based on the recently measured cyclotron line of Swift J0243. The spin-up rate and luminosity of SMC X-3 follows a relation of $\dot{\nu}\propto L^{0.94\pm0.03}$, while that of RX J0209 follows $\dot{\nu}\propto L^{1.00\pm0.03}$, which are similar to Swift J0243 and consistent with the prediction of a radiation-pressure-dominated (RPD) disk. These results indicate that accretion columns are indeed formed above Eddington luminosity, and the population of ULXPs likely corresponds to X-ray pulsars of highest magnetic field.

The evolution of intermediate-mass and massive stars speeds up considerably after they finish their hydrogen core-burning. Due to this accelerated evolution, the probability to observe stars during this episode is small. In suitable stellar aggregates, in particular star clusters of appropriate ages, the fast evolutionary phase causes a depopulated area~--~referred to as the Hertzsprung gap~--~in color-magnitude diagrams and derivatives therefrom. The explanation of the speed-up usually resorts to the star's Kelvin-Helmholtz timescale and the Sch\"onberg-Chandrasekhar instability is called upon. This exposition challenges this viewpoint with counterexamples and argues that a suitably defined nuclear timescale is enough to explain the fast evolution. A thermal instability, even though it develops in stars evolving through the Hertzsprung gap, is not a necessary condition to trigger the phenomenon.

Infrared spectroscopy over a wide spectral range and at the highest resolving powers (R>70 000) has proved to be one of the leading technique to unveil the atmospheric composition of dozens of exoplanets. The recently upgraded spectrograph CRIRES instrument at the VLT (CRIRES+) was operative for a first Science Verification in September 2021 and its new capabilities in atmospheric characterisation were ready to be tested. We analysed transmission spectra of the Hot Saturn WASP-20b in the K-band (1981-2394 nm) acquired with CRIRES+, aiming at detecting the signature of H2O and CO. We used Principal Component Analysis to remove the dominant time-dependent contaminating sources such as telluric bands and the stellar spectrum and we extracted the planet spectrum by cross-correlating observations with 1D and 3D synthetic spectra, with no circulation included. We present the tentative detection of molecular absorption from water-vapour at S/N equal to 4.2 and 4.7 by using only-H2O 1D and 3D models, respectively. The peak of the CCF occurred at the same rest-frame velocity for both model types (Vrest=-1 $\pm$ 1 kms$^{-1}$), and at the same projected planet orbital velocity but with different error bands (1D model: KP=131$^{+18}_{-29}$ kms$^{-1}$; 3D: KP=131$^{+23}_{-39}$ kms$^{-1}$). Our results are in agreement with the one expected in literature (132.9 $\pm$ 2.7 kms$^{-1}$). Although sub-optimal observational conditions and issues with pipeline in calibrating and reducing our raw data set, we obtained the first tentative detection of water in the atmosphere of WASP-20b. We suggest a deeper analysis and additional observations to confirm our results and unveil the presence of CO.

Selected for the next generation of adaptive optics (AO) systems, the pyramid wavefront sensor (PWFS) is recognised for its closed AO loop performance. As new technologies are emerging, it is necessary to explore new methods to improve it. Microwave Kinetic Inductance Detectors (MKID) are photon-counting devices that measure the arrival time and energy of each incident photon, providing new capabilities over existing detectors and significant AO performance benefits. After developing a multi-wavelength PWFS simulation, we study the benefits of using an energy sensitive detector, analyse the PWFS performance according to wavelength and explore the possibility of using fainter natural guide stars by widening the bandpass of the wavefront sensor.

In the preliminary design of space missions it can be useful to identify regions of dynamics that drive the system's behaviour or separate qualitatively different dynamics. The Lagrangian Coherent Structure (LCS) has been widely used in the analysis of dynamical systems, and generalises the concept of the stable and unstable manifolds to systems with arbitrary time-dependence. However, the use of three-dimensional LCS in astrodynamics has thus far been limited. This paper presents the application of a new numerical method introduced by the authors, DA-LCS, to astrodynamics systems using the Elliptic-Restricted Three-body Problem (ER3BP) as a test case. We are able to construct the full, three-dimensional LCS associated with the Sun-Mars ER3BP directly from the variational theory of LCS even for numerically challenging initial conditions. The LCS is analysed in detail, showing how it in this case separates regions of qualitatively different behaviour without any a priori knowledge. The paper then studies the effect of integration time and the parameterisation of the initial condition on the LCS found. We highlight how round-off errors arise from limits of floating-point arithmetic in the most challenging test cases and provide mitigating strategies for avoiding these errors practically.

Phase diagrams of fully ionized binary ionic mixtures are considered within the framework of the linear mixing formalism taking into account recent advances in understanding quantum one-component plasma thermodynamics. We have followed a transformation of azeotropic phase diagrams into peritectic and eutectic types with increase of the charge ratio. For solid $^{12}$C/$^{16}$O and $^{16}$O/$^{20}$Ne mixtures, we have found extensive miscibility gaps. Their appearance seems to be a robust feature of the theory. The gaps evolve naturally into two-solid regions of eutectic phase diagrams at higher $Z_2/Z_1$. They do not depend on thermodynamic fit extensions beyond their applicability limits. The gaps are sensitive to binary mixture composition and physics, being strongly different for C/O and O/Ne mixtures and for the three variants of corrections to linear-mixing solid-state energies available in the literature. When matter cools to its miscibility gap temperature, the exsolution process takes place. It results in a separation of heavier and lighter solid solutions. This may represent a significant reservoir of gravitational energy and should be included in future white dwarf (WD) cooling simulations. Ion quantum effects mostly resulted in moderate modifications, however, for certain $Z_2/Z_1$, these effects can produce qualitative restructuring of the phase diagram. This may be important for the model with $^{22}$Ne distillation in cooling C/O/Ne WD proposed as a solution for the ultramassive WD cooling anomaly.

A significant fraction of spiral galaxies are red, gas-poor, and have low star formation rates (SFRs). We study these unusual objects using the IllustrisTNG100 simulation. Among 1912 well-resolved disk galaxies selected from the last simulation output, we identify 377 red objects and describe their properties and origins using a few representative examples. The simulated red spirals turn out to be typically very gas-poor, have very low SFRs, are more metal-rich, and have larger stellar masses than the remaining disks. Only about 13% of red spirals suffered strong mass loss and thus could have resulted from environmental quenching by ram pressure and tidal stripping of the gas, or similar processes. The majority of red disks were probably quenched by feedback from the active galactic nucleus (AGN). This conclusion is supported by the higher black hole masses and lower accretion rates of red disks, as well as the larger total AGN feedback energies injected into the surrounding gas in the kinetic feedback mode implemented in the IllustrisTNG simulations. The timescales of the gas loss correlate with the black hole growth for the AGN-quenched galaxies and with the dark-matter loss for the environmentally quenched ones. The red spirals are more likely to possess bars, and their bars are stronger than in the remaining disks, which is probably the effect of gas loss rather than the reason for quenching.

The magnetic field of a host star can impact the orbit of a stellar partner, planet, or asteroid if the orbiting body is itself magnetic or electrically conducting. Here, we focus on the instantaneous magnetic forces on an orbiting body in the limit where the dipole approximation describes its magnetic properties as well as those of its stellar host. A permanent magnet in orbit about a star will be inexorably drawn toward the stellar host if the magnetic force is comparable to gravity due to the steep radial dependence of the dipole-dipole interaction. While magnetic fields in observed systems are much too weak to drive a merger event, we confirm that they may be high enough in some close compact binaries to cause measurable orbital precession. When the orbiting body is a conductor, the stellar field induces a time-varying magnetic dipole moment that leads to the possibility of eccentricity pumping and resonance trapping. The challenge is that the orbiter must be close to the stellar host, so that magnetic interactions must compete with tidal forces and the effects of intense stellar radiation.

As part of the GRAVITY$^{+}$ project, the near-infrared beam combiner GRAVITY and the VLTI are currently undergoing a series of significant upgrades to further improve the performance and sky coverage. The instrumental changes will be transformational, and for instance uniquely position GRAVITY to observe the broad line region of hundreds of Active Galactic Nuclei (AGN) at a redshift of two and higher. The increased sky coverage is achieved by enlarging the maximum angular separation between the celestial science object (SC) and the off-axis fringe tracking (FT) star from currently 2 arcseconds (arcsec) up to unprecedented 30 arcsec, limited by the atmospheric conditions. This was successfully demonstrated at the VLTI for the first time.

The ESO Science Archive is the collection and access point of the data generated at ESO's La Silla Paranal Observatory, both raw and processed. It is a major contributor to ESO's science output, being used in about 4 out of 10 refereed articles with ESO data. In this paper, which is presented on behalf of the operations and development teams, we review its contents, policies, us interfaces and impact.

In the next decade, radio telescopes like the Square Kilometer Array (SKA) will explore the Universe at high redshift, and particularly during the Epoch of Reionisation (EoR). The first structures emerged during this epoch, and their radiations have reionised the previously cold and neutral gas of the Universe creating ionised bubbles that percolate at the end of the EoR (at a redshift of approximately 6). SKA will produce 2D images of the distribution of the neutral gas at many redshifts, pushing us to develop tools and simulations to understand its properties. This paper aims at measuring topological statistics of the EoR in the so-called "reionisation time" fields from both cosmological and semi-analytical simulations. This field informs us about the time of reionisation of the gas at each position. We also compare these measurements with analytical predictions obtained within the gaussian random field (GRF) theory. The gaussian random fields (GRFs) theory allows us to compute many statistics of a field: probability distribution functions (PDFs) of the field or its gradient, isocontour length, critical point distributions, and skeleton length. We compare these theoretical predictions to measurements made on reionisation time fields extracted from an EMMA and a 21cmFAST simulations at 1 a cMpc/h resolution. We also compared our results to GRFs generated from the fitted power spectra of the simulation maps. Both EMMA and 21cmFAST reionisation time fields (treion(r)) are close to be gaussian fields, in contrast with the 21 cm, density or ionisation fraction that are all proven to be non-gaussian. Only accelerating ionisation fronts at the end of the EoR seem to be a cause of small non-gaussianities in treion(r). Overall our results indicate that an analytical description of the reionisation percolation can be reasonably made within the framework of GRF theory.

We present a new statistics based on the turn-around radii of cluster halos to break the dark sector degeneracy between the $\Lambda$CDM model and the alternative ones with $f(R)$ gravity and massive neutrinos ($\nu$) characterized by the strength of the fifth force, $\vert f_{R0}\vert$, and the total neutrino mass, $M_{\nu}$. Analyzing the rockstar halo catalogs at the present epoch from the {\small DUSTGRAIN}-{pathfinder} $N$-body simulations performed for four different cosmologies, namely, $\Lambda$CDM ($\vert f_{R0}\vert=0$, $M_{\nu}=0.0$eV), fR6 ($\vert f_{R0}\vert=10^{-6}$, $M_{\nu}=0.0$eV), fR6+$0.06$eV ($\vert f_{R0}\vert=10^{-6}$, $M_{\nu}=0.06$eV) and fR5+$0.15$eV ($\vert f_{R0}\vert=10^{-5}$, $M_{\nu}=0.15$eV), which are known to yield very similar conventional statistics to one another. For each model, we select those cluster halos which do not neighbor any other larger halos in their bound zones and construct their bound-zone peculiar velocity profiles at $z=0$. Then, we determine the radial distance of each selected halo at which the bound-zone velocity becomes equal to the recession speed of the Hubble flow as its turn around radius, and evaluate the cumulative probability distribution of the ratios of the turn-around radii to the virial counterparts, $P(r_{t}/r_{v}\ge \alpha)$. The degeneracy between the fR6 and fR5+$0.15$eV models is found to be readily broken by the $10\sigma_{\Delta P}$ difference in the value of $P(\alpha=4)$, while the $3.2\sigma_{\Delta P}$ difference between the $\Lambda$CDM and fR6+$0.06$eV models is detected in the value of $P(\alpha=8.5)$. It is also found that the four models yield smaller differences in $P(\alpha)$ at higher redshifts.

Classical DQ stars are white dwarfs whose atmospheres contain detectable traces of carbon brought up to the surface by a convective dredge-up process. Intriguingly, unlike other white dwarf spectral classes, DQ stars virtually never show signs of external pollution by elements heavier than carbon. In this Letter, we solve this long-standing problem by showing that the absence of detectable external pollution in DQ stars is naturally explained by the impact of metal accretion on the atmospheric structure of the white dwarf. A DQ star that accretes heavy elements sees its atmospheric density decrease, which leads to a sharp drop in the molecular carbon abundance and a strong suppression of the C$_2$ Swan bands. We show that a typical DQ star that accretes heavy elements from planetary material generally transforms directly into a DZ star.

We present an experiment set to address a standard specification aiming at avoiding local turbulence inside the Coud\'e train of telescopes. Namely, every optical surface should be kept within a 1.5$^\circ$ range around ambient temperature. Such a specification represents an important concern and constraint when developing optical systems for astronomy. Our aim was to test its criticality in the context of the development of the VLTI/NAOMI and VLTI/GRAVITY+ adaptive optics. This experiment has been conducted using the hardware of the future Corrective Optics (CO) of GRAVITY+. Optical measurements were performed in order to observe the evolution of turbulence in front of a flat mirror for which the surface temperature was controlled in a range of $22^\circ$ above ambient temperature. A time-dependent analysis of the turbulence was led along with a spatial analysis. This experiment shows no influence of temperature on local turbulence. It should be noted however that this result is only applicable to the very specific geometry described in this paper, which is representative of an adaptive optics (AO) system located inside the Coud\'e train (facing-down mirror heated on its backface).

Observations of surface magnetic fields of cool stars reveal a large diversity of configurations. Although there is now a consensus that these fields are generated through dynamo processes occurring within the convective zone, the physical mechanism driving such a variety of field topologies is still debated. This paper discusses the possible origins of dipole and multipole-dominated morphologies using three-dimensional numerical simulations of stratified systems where the magnetic feedback on the fluid motion is significant. Our main result is that dipolar solutions are found at Rossby numbers up to 0.4 in strongly stratified simulations, where previous works suggested that only multipolar fields should exist. We argue that these simulations are reminiscent of the outlier stars observed at Rossby numbers larger than 0.1, whose large-scale magnetic field is dominated by their axisymmetric poloidal component. As suggested in previous Boussinesq calculations, the relative importance of inertial over Lorentz forces is again controlling the dipolar to multipolar transition. Alternatively, we find that the ratio of kinetic to magnetic energies can equally well capture the transition in the field morphology. We test the ability of this new proxy to predict the magnetic morphology of a few M-dwarf stars whose internal structure matches that of our simulations and for which homogeneous magnetic field characterization is available. Finally, the magnitude of the differential rotation obtained in our simulations is compared to actual measurements reported in the literature for M-dwarfs. In our simulations, we find a clear relationship between anti-solar differential rotation and the emergence of dipolar fields.

One of the open issues of the standard cosmological model is the value of the cosmic dipole measured from the Cosmic Microwave Background (CMB), as well as from the number count of quasars and radio sources. These measurements are currently in tension, with the number count dipole being 2-5 times larger than expected from CMB measurements. This discrepancy has been pointed out as a possible indication that the cosmological principle is not valid. In this paper, we explore the possibility of detecting and estimating the cosmic dipole with gravitational waves (GWs) from compact binary mergers detected by the future next-generation detectors Einstein Telescope and Cosmic Explorer. We model the expected signal and show that for binary black holes, the dipole amplitude in the number count of detections is independent of the characteristics of the population and provides a systematic-free tool to estimate the observer velocity. We introduce techniques to detect the cosmic dipole from number counting of GW detections and estimate its significance. We show that a GW dipole consistent with the amplitude of the dipole in radio galaxies would be detectable with $>3\sigma$ significance with a few years of observation ($10^6$ GW detections) and estimated with a $16\%$ precision, while a GW dipole consistent with the CMB one would require at least $10^7$ GW events for a confident detection. We also demonstrate that a total number $N_{\rm tot}$ of GW detections would be able to detect a dipole with amplitude $v_o/c \simeq1/\sqrt{N_{\rm tot}}$.

Precise measurements of the Planck cosmic microwave background (CMB) angular power spectrum (APS) at small angles have stimulated accurate statistical analyses of the lensing amplitude parameter $A_{L}$. To confirm if it satisfies the value expected by the flat-$\Lambda$CDM concordance model, i.e. $A_{L} = 1$, we investigate the spectrum difference obtained as: the difference of the measured Planck CMB APS and the Planck best-fit $\Lambda$CDM APS model. To know if this residual spectrum corresponds to statistical noise or if it has a hiden signature that can be accounted for with a larger lensing amplitude $A_{L} > 1$, we apply the Ljung-Box statistical test and find, with high statistical significance, that the spectrum difference is not statistical noise. This spectrum difference is then analysed in detail using simulated APS, based on the Planck $\Lambda$CDM best-fit model, where the lensing amplitude is a free parameter. We explore different binnations of the multipole order \,$\ell$\, and look for the best-fit lensing amplitude parameter that accounts for the spectrum difference in a $\chi^2$ procedure. We find that there is an excess of signal that is well explained by a $\Lambda$CDM APS with a non-null lensing amplitude parameter $A_{lens}$, with values in the interval $[0.10,0.29]$ at 68\% confidence level. Furthermore, the lensing parameter in the Planck APS should be $1 + A_{lens} > 1$ at $\sim 3 \sigma$ of statistical confidence. Additionally, we perform statistical tests that confirm the robustness of this result. Important to say that this excess of lensing amplitude, not accounted in the Planck's flat-$\Lambda$CDM model, could have an impact on the theoretical expectation of large-scale structures formation once the scales where it was detected correspond to these matter clustering processes.

We present the first results of a comprehensive supernova (SN) radiative-transfer (RT) code-comparison initiative (StaNdaRT), where the emission from the same set of standardized test models is simulated by currently-used RT codes. A total of ten codes have been run on a set of four benchmark ejecta models of Type Ia supernovae. We consider two sub-Chandrasekhar-mass ($M_\mathrm{tot} = 1.0$ M$_\odot$) toy models with analytic density and composition profiles and two Chandrasekhar-mass delayed-detonation models that are outcomes of hydrodynamical simulations. We adopt spherical symmetry for all four models. The results of the different codes, including the light curves, spectra, and the evolution of several physical properties as a function of radius and time, are provided in electronic form in a standard format via a public repository. We also include the detailed test model profiles and several python scripts for accessing and presenting the input and output files. We also provide the code used to generate the toy models studied here. In this paper, we describe in detail the test models, radiative-transfer codes and output formats and provide access to the repository. We present example results of several key diagnostic features.

Several important properties of rotation-powered millisecond pulsars (MSPs), such as their mass-radius ratio, equation of state and magnetic field topology, can be inferred from precise observations and modelling of their X-ray light curves. In the present study, we model the thermal X-ray signals originated in MSPs, all the way from numerically solving the surrounding magnetospheres up to the ray tracing of the emitted photons and the final computation of their light curves and spectra. Our modelled X-ray signals are then compared against a set of very accurate NICER observations of four target pulsars: PSR J0437-4715, PSR J1231-1411, PSR J2124-3358 and PSR J0030+0451. We find very good simultaneous fits for the light curve and spectral distribution in all these pulsars. The magnetosphere is solved by performing general relativistic force-free simulations of a rotating neutron star (NS) endowed with a simple centered dipolar magnetic field, for many different stellar compactness and pulsar misalignments. From these solutions, we derive an emissivity map over the surface of the star, which is based on the electric currents in the magnetosphere. In particular, the emission regions (ERs) are determined in this model by spacelike four-currents that reach the NS. We show that this assumption, together with the inclusion of the gravitational curvature on the force-free simulations, lead to non-standard ERs facing the closed-zone of the pulsar, in addition to other ERs within the polar caps. The combined X-ray signals from these two kinds of ERs (both antipodal) allow to approximate the non-trivial interpulses found in all the target MSPs light curves.

Solar system exploration provides numerous possibilities for advancing technosignature science. The search for life in the solar system includes missions designed to search for evidence of biosignatures on other planetary bodies, but many missions could also attempt to search for and constrain the presence of technology within the solar system. Technosignatures and biosignatures represent complementary approaches toward searching for evidence of life in our solar neighborhood, and beyond. This report summarizes the potential technosignature opportunities within ongoing solar system exploration and the recommendations of the "Origins, Worlds, and Life" Planetary Science and Astrobiology Decadal Survey. We discuss opportunities for constraining the prevalence of technosignatures within the solar system using current or future missions at negligible additional cost, and we present a preliminary assessment of gaps that may exist in the search for technosignatures within the solar system.

BINGO will observe hydrogen distribution by means of the 21 cm line signal by drift-scan mapping through a tomographic analysis called \emph{Intensity Mapping} (IM) between 980 and 1260 MHz which aims at analyzing Dark Energy using \emph{Baryon Acoustic Oscillations}. In the same frequency range, there are several other unwanted signals as well as instrumental noise, contaminating the target signal. There are many component separation methods to reconstruct signals. Here, we used just three blind methods (FastICA, GNILC and GMCA), which explore different ways to estimate foregrounds' contribution from observed signals from the sky. Subsequently, we estimate 21 cm signal from its mixing with noise. We also analyzed how different number of simulations affect the quality of the estimation, as well as the effect of the binning on angular power spectrum to estimate 21 cm from the mixing with noise. For the BINGO sky range and sensitivity and the foreground model considered in the current simulation, we find that the effective dimension of the foreground subspace leading to best results is equal to three, composed of non-physical templates. At this moment of the pipeline configuration, using 50 or 400 simulations is statistically equivalent. It is also possible to reduce the number of multipoles by half to speed up the process and maintain the quality of results. All three algorithms used to perform foreground removal yielded statistically equivalent results for estimating the 21cm signal when we assume 400 realizations and GMCA and FastICA's mixing matrix dimensions equal to three. However, concerning computational cost in this stage of the BINGO pipeline, FastICA is faster than other algorithms. A new comparison will be necessary when the time-ordered-data and map-making are available.

[Abridged] We present a novel method to study the thermal emission of exoplanets as a function of orbital phase at very high spectral resolution, and apply it to investigate the climate of the ultra-hot Jupiter KELT-9b. We combine 3 nights of HARPS-N and 2 nights of CARMENES optical spectra, covering orbital phases between quadratures (0.25 < phi < 0.75), when the planet shows its day-side hemisphere with different geometries. We co-add the signal of thousands of FeI lines through cross-correlation, which we map to a likelihood function. We investigate the phase-dependence of: (i) the line depths of FeI, and (ii) their Doppler shifts, by introducing a new method that exploits the very high spectral resolution of our observations. We confirm a previous detection of FeI emission and demonstrate a combined precision of 0.5 km s-1 on the orbital properties of KELT-9b. By studying the phase-resolved Doppler shift of FeI lines, we detect an anomaly in the planet's orbital radial velocity well-fitted with a slightly eccentric orbit (e = 0.016$\pm$0.003, w = 150$^{+13\circ}_{-11},~5\sigma$ preference). However, we argue that such anomaly can be explained by a day-night wind of a few km s-1 blowing neutral iron gas. Additionally, we find that the FeI emission line depths are symmetric around the substellar point within 10 deg ($2\sigma$). We show that these results are qualitatively compatible with predictions from general circulation models for ultra-hot Jupiter planets. Very high-resolution spectroscopy phase curves have the sensitivity to reveal a phase dependence in both the line depths and their Doppler shifts throughout the orbit. They are highly complementary to space-based phase curves obtained with HST and JWST, and open a new window into the still poorly understood climate and atmospheric structure of the hottest planets known.

The superheterodyne structure, currently employed by the receivers developed by the Laboratory for Spatial Studies and Instrumentation (LESIA) of the Paris Observatory, rely on pass-band filters with very high quality factors. This makes them difficult to integrate on microchips. We present here another topology that is easier to integrate into microchips intended for space studies. After presenting the general topology, we propose a design of an electronic receiver based on this topology and present its design charts.

We present a post-processing catalog of globular clusters (GCs) for the $39$ most massive groups and clusters in the TNG50 simulation of the IlllustrisTNG project (virial masses $M_{200} =[5\times 10^{12} \rm - 2 \times 10^{14}$] M$_{\odot}$). We tag GC particles to all galaxies with stellar mass $M_* \geq 5\times10^6$ M$_{\odot}$, and we calibrate their masses to reproduce the observed power-law relation between GC mass and halo mass for galaxies with $M_{200} \geq 10^{11}$ M$_{\odot}$ (corresponding to $M_* \sim 10^9$ $M_{\odot}$). Here we explore whether an extrapolation of this $M_{\rm GC}$-$M_{200}$ relation to lower-mass dwarfs is consistent with current observations. We find a good agreement between our predicted number and specific frequency of GCs in dwarfs with $\rm M_*=[5 \times 10^6 \rm - 10^9]$ M$_{\odot}$ and observations. Moreover, we predict a steep decline in the GC occupation fraction for dwarfs with $M_*<10^9$ M$_{\odot}$ which agrees well with current observational constraints. This declining occupation fraction is due to a combination of tidal stripping in all dwarfs plus a stochastic sampling of the GC mass function for dwarfs with $M_* < 10^{7.5}$ M$_{\odot}$. Our simulations also reproduce available constraints on the abundance of intra-cluster GCs in Virgo and Centaurus A. These successes provide support to the hypothesis that the $M_{\rm GC}$-$M_{200}$ relation holds, albeit with more scatter, all the way down to the regime of classical dwarf spheroidals in these environments. Our GC catalogs are publicly available as part of the IllustrisTNG data release.

In compact astrophysical objects, the neutrino density can be so high that neutrino-neutrino refraction can lead to fast flavor conversion of the kind $\nu_e \bar\nu_e \leftrightarrow \nu_x \bar\nu_x$ with $x=\mu,\tau$, depending on the neutrino angle distribution. Previously, we have shown that in a homogeneous, axisymmetric two-flavor system, these collective solutions evolve in analogy to a gyroscopic pendulum. In flavor space, its deviation from the weak-interaction direction is quantified by a variable $\cos\vartheta$ that moves between $+1$ and $\cos\vartheta_{\rm min}$, the latter following from a linear mode analysis. As a next step, we include collisional damping of flavor coherence, assuming a common damping rate $\Gamma$ for all modes. Empirically we find that the damped pendular motion reaches an asymptotic level of pair conversion $f=A+(1-A)\cos\vartheta_{\rm min}$ (numerically $A\simeq 0.370$) that does not depend on details of the angular distribution (except for fixing $\cos\vartheta_{\rm min}$), the initial seed, nor $\Gamma$. On the other hand, even a small asymmetry between the neutrino and antineutrino damping rates strongly changes this picture and can even enable flavor instabilities in otherwise stable systems. Furthermore, we establish a formal connection with a stationary and inhomogeneous neutrino ensemble, showing that our findings also apply to this system.

Primordial Black Holes (PBH) could dominate in the early Universe and, evaporating before Big bang Nucleosynthesis, can provide new freeze in mechanism of dark matter (DM) production. The proposed scenario is considered for two possible mechanisms of PBH formation and the corresponding continuous PBH mass spectra so that the effect of non-single PBH mass spectrum is taken into account in the results of PBH evaporation, by which PBH dominance in the early Universe ends. We specify the conditions under which the proposed scenario can explain production of dark matter in very early Universe.

We demonstrate a new geometric method for fast template placement for searches for gravitational waves from the inspiral, merger and ringdown of compact binaries. The method is based on a binary tree decomposition of the template bank parameter space into non-overlapping hypercubes. We use a numerical approximation of the signal overlap metric at the center of each hypercube to estimate the number of templates required to cover the hypercube and determine whether to further split the hypercube. As long as the expected number of templates in a given cube is greater than a given threshold, we split the cube along its longest edge according to the metric. When the expected number of templates in a given hypercube drops below this threshold, the splitting stops and a template is placed at the center of the hypercube. Using this method, we generate aligned-spin template banks covering the mass range suitable for a search of Advanced LIGO data. The aligned-spin bank required ~24 CPU-hours and produced 2 million templates. In general, we find that other methods, namely stochastic placement, produces a more strictly bounded loss in match between waveforms, with the same minimal match between waveforms requiring about twice as many templates with our proposed algorithm. Though we note that the average match is higher, which would lead to a higher detection efficiency. Our primary motivation is not to strictly minimize the number of templates with this algorithm, but rather to produce a bank with useful geometric properties in the physical parameter space coordinates. Such properties are useful for population modeling and parameter estimation.

The determination of astrophysical reaction rates requires different approaches depending on the conditions in hydrostatic and explosive burning. The focus here is on astrophysical reaction rates for radiative neutron capture reactions. Relevant nucleosynthesis processes not only involve the s-process but also the i-, r- and $\gamma$-processes, which from the nuclear perspective mainly differ in the relative interaction energies of neutrons and nuclei, and in the nuclear level densities of the involved nuclei. Emphasis is put on the difference between reactions at low and high temperature. Possible complications in the prediction and measurement of these reaction rates are illustrated and the connection between theory and experiment is addressed.

Gravitational-wave detections of black hole mergers in binary systems offer an excellent opportunity to test the 2nd law of black hole thermodynamics. In this paper, we review how the entropy of any astrophysical black hole is calculated and we use LIGO and VIRGO's mass and spin data measurements from black hole merger events detected over the past years to perform entropy calculations and numerically test the generalized 2nd law of thermodynamics. Besides, we analyze the mathematical correlation between the black hole merger event's initial parameters to prove and conclude that the theorem will always hold.

We investigate the form of the radiation emitted by an axion star-neutron star binary using a $f(r)=\text{sech(r/R)}$ profile for the axion star. Our analysis takes into account the co-rotating plasma of the neutron star. We find that that there is significant enhancement to the radiated power if the neutron star's spin is tilted towards the plane of the axion star-neutron star orbit, compared to the case where it is perpendicular. We also examine whether the neutron star's co-rotating plasma can play a role in the emitted power and we find that even though dilute axion stars can in principle radiate more efficiently than dense axion stars, they will be pulled apart by the tidal forces of the neutron star

In this research we consider a $U(1)_X$ gauge boson acting as a dark matter candidate. The vector dark matter gets mass when a complex singlet scalar breaks the gauge symmetry spontaneously. The dark matter candidates communicate with the SM particles via a scalar-Higgs portal. The focus in this work is on the dark matter mass smaller than 10 GeV. This parameter space is not studied thoroughly before. Dark matter annihilation via forbidden channel and near pole are studied in order to place constraints from observed relic density and CMB. Other bounds from colliders, beam-dump experiments, and astrophysical observations are imposed. Taking into account all the bounds including the direct detection upper limits, the viable space is achieved.