Miracle-dz/UniFAR-FTUs huggingface dataset:
BULGES OF NEARBY GALAXIES WITH SPITZER: SCALING RELATIONS IN PSEUDOBULGES AND CLASSICAL BULGES

We investigate scaling relations of bulges using bulge–disk decompositions at 3.6 μm and present bulge classifications for 173 E-Sd galaxies within 20 Mpc. Pseudobulges and classical bulges are identified using Sérsic index, Hubble Space Telescope morphology, and star formation activity (traced by 8 μm emission). In the near-IR pseudobulges have nb < 2 and classical bulges have nb>2, as found in the optical. Sérsic index and morphology are essentially equivalent properties for bulge classification purposes. We confirm, using a much more robust sample, that the Sérsic index of pseudobulges is uncorrelated with other bulge structural properties, unlike for classical bulges and elliptical galaxies. Also, the half-light radius of pseudobulges is not correlated with any other bulge property. We also find a new correlation between surface brightness and pseudobulge luminosity; pseudobulges become more luminous as they become more dense. Classical bulges follow the well-known scaling relations between surface brightness, luminosity, and half-light radius that are established by elliptical galaxies. We show that those pseudobulges (as indicated by Sérsic index and nuclear morphology) that have low specific star formation rates are very similar to models of galaxies in which both a pseudobulge and classical bulge exist. Therefore, pseudobulge identification that relies only on structural indicators is incomplete. Our results, especially those on scaling relations, imply that pseudobulges are very different types of objects than elliptical galaxies.
The GALEX view of the Herschel Reference Survey - Ultraviolet structural properties of nearby galaxies

We present GALEX far-ultraviolet (FUV) and near-ultraviolet (NUV) as well as SDSS g, r, i photometry and structural parameters for the Herschel Reference Survey, a magnitude-, volume-limited sample of nearby galaxies in different environments. We use this unique dataset to investigate the ultraviolet (UV) structural scaling relations of nearby galaxies and to determine how the properties of the UV disk vary with atomic hydrogen content and environment. We find a clear change of slope in the stellar mass vs. effective surface brightness relation when moving from the optical to the UV, with more massive galaxies having brighter optical but fainter UV surface brightnesses than smaller systems. A similar change of slope is also seen in the radius vs. surface brightness relation. By comparing our observations with the predictions of a simple multi-zone chemical model of galaxy evolution, we show that these findings are a natural consequence of a much more efficient inside-out growth of the stellar disk in massive galaxies. We confirm that isophotal radii are always a better proxy for the size of the stellar/star-forming disk than effective quantities and we show that the extent of the UV disk (normalized to the optical size) is strongly correlated to the integrated Hi gas fraction. This relation still holds even when cluster spirals are considered, with Hi-deficient systems having less extended star-forming disks than Hi-normal galaxies. Interestingly, the star formation in the inner part of Hi-deficient galaxies is significantly less affected by the removal of the atomic hydrogen, as expected in a simple ram-pressure stripping scenario. These results suggest that it is the amount of Hi that regulates the growth of the star-forming disk in the outskirts of galaxies.
TESTING FOR A LARGE LOCAL VOID BY INVESTIGATING THE NEAR-INFRARED GALAXY LUMINOSITY FUNCTION

Recent cosmological modeling efforts have shown that a local underdensity on scales of a few hundred Mpc (out to z ∼ 0.1) could produce the apparent acceleration of the expansion of the universe observed via Type Ia supernovae. Several studies of galaxy counts in the near-infrared (NIR) have found that the local universe appears underdense by ∼25%–50% compared with regions a few hundred Mpc distant. Galaxy counts at low redshifts sample primarily L ∼ L* galaxies. Thus, if the local universe is underdense, then the normalization of the NIR galaxy luminosity function (LF) at z > 0.1 should be higher than that measured for z < 0.1. Here we present a highly complete (>90%) spectroscopic sample of 1436 galaxies selected in the H band (1.6 μm) to study the normalization of the NIR LF at 0.1 < z < 0.3 and address the question of whether or not we reside in a large local underdensity. Our survey sample consists of all galaxies brighter than 18th magnitude in the H band drawn from six widely separated fields at high Galactic latitudes, which cover a total of ∼2 deg2 on the sky. We find that for the combination of our six fields, the product ϕ*L* at 0.1 < z < 0.3 is ∼30% higher than that measured at lower redshifts. While our statistical errors in this measurement are on the ∼10% level, we find the systematics due to cosmic variance may be larger still. We investigate the effects of cosmic variance on our measurement using the COSMOS cone mock catalogs from the Millennium Simulation and recent empirical estimates of cosmic variance. We find that our survey is subject to systematic uncertainties due to cosmic variance at the 15% level (1σ), representing an improvement by a factor of ∼2 over previous studies in this redshift range. We conclude that observations cannot yet rule out the possibility that the local universe is underdense at z < 0.1. The fields studied in this work have a large amount of publicly available ancillary data and we make available the images and catalogs used here.
Evolution of massive Population III stars with rotation and magnetic fields

[Abridged] We present a new grid of massive population III star models including the effects of rotation on the stellar structure and chemical mixing, and magnetic torques for the transport of angular momentum. Based on the grid, we also present a phase diagram for the expected final fates of rotating massive Pop III stars. Our non-rotating models become redder than the previous models in the literature, given the larger overshooting parameter adopted in this study. In particular, convective dredge-up of the helium core material into the hydrogen envelope is observed in our non-rotating very massive star models (>~200 Msun), which is potentially important for the chemical yields. On the other hand, the stars become bluer and more luminous with a higher rotational velocity. With the Spruit-Tayler dynamo, our models with a sufficiently high initial rotational velocity can reach the critical rotation earlier and lose more mass as a result, compared to the previous models without magnetic fields. The most dramatic effect of rotation is found with the so-called chemically homogeneous evolution (CHE), which is observed for a limited mass and rotational velocity range. CHE has several important consequences: 1) Both primary nitrogen and ionizing photons are abundantly produced. 2) Conditions for gamma-ray burst progenitors are fulfilled for an initial mass range of 13 - 84 Msun. 3) Pair instability supernovae of type Ibc are expected for 84 -190 Msun and 4) Both a pulsational pair instability supernova and a GRB may occur from the same progenitor of about 56 - 84 Msun, which might significantly influence the consequent GRB afterglow. We find that CHE does not occur for very massive stars (>190 Msun), in which case the hydrogen envelope expands to the red-supergiant phase and the final angular momentum is too low to make any explosive event powered by rotation.
TWO EXTREME YOUNG OBJECTS IN BARNARD 1-b

Two submillimeter/millimeter sources in the Barnard 1b (B1-b) core, B1-bN and B1-bS, have been studied in dust continuum, H13CO+ J = 1–0, CO J = 2–1, 13CO J = 2–1, and C18O J = 2–1. The spectral energy distributions of these sources from the mid-IR to 7 mm are characterized by very cold temperatures of Tdust < 20 K and low bolometric luminosities of 0.15–0.31 L☉. The internal luminosities of B1-bN and B1-bS are estimated to be <0.01–0.03 L☉ and ∼0.1–0.2 L☉, respectively. Millimeter interferometric observations have shown that these sources have already formed central compact objects of ∼100 AU sizes. Both B1-bN and B1-bS are driving the CO outflows with low characteristic velocities of ∼2–4 km s−1. The fractional abundance of H13CO+ at the positions of B1-bN and B1-bS is lower than the canonical value by a factor of four to eight. This implies that a significant fraction of CO is depleted onto dust grains in the dense gas surrounding these sources. The observed physical and chemical properties suggest that B1-bN and B1-bS are in an earlier evolutionary stage than most of the known class 0 protostars. In particular, the properties of B1-bN agree with those of the first hydrostatic core predicted by the MHD simulations. The CO outflow was also detected in the mid-IR source located at ∼15″ from B1-bS. Since the dust continuum emission was not detected in this source, the circumstellar material surrounding this source is less than 0.01 M☉. It is likely that the envelope of this source was dissipated by the outflow from the protostar that is located to the southwest of B1-b.
Gas sloshing, cold front formation and metal redistribution: the Virgo cluster as a quantitative test case

We perform hydrodynamical simulations of minor-merger-induced gas sloshing and the subsequent formation of cold fronts in the Virgo cluster. Comparing to observations, we show for the first time that the sloshing scenario can reproduce the radii and the contrasts in X-ray brightness, projected temperature and metallicity across the cold fronts quantitatively. The comparison suggests a third cold front 20 kpc north-west of the Virgo core. We identify several new features typical for sloshing cold fronts: an alternating distribution of cool, metal-enriched X-ray brightness excess regions and warm brightness deficit regions of reduced metallicity; a constant or radially decreasing temperature accompanied by a plateau in metallicity inside the cold fronts; a warm rim outside the cold fronts and a large-scale brightness asymmetry. We can trace these new features not only in Virgo, but also in other clusters exhibiting sloshing cold fronts. By comparing synthetic and real observations, we estimate that the original minor-merger event took place about 1.5 Gyr ago when a subcluster of 1-4 x 10 13 M ⊙ passed the Virgo core at 100-400 kpc distance, where a smaller mass corresponds to a smaller pericentre distance, and vice versa. From our inferred merger geometry, we derive the current location of the disturbing subcluster to be about 1-2 Mpc east of the Virgo core. A possible candidate is M60. Additionally, we quantify the metal redistribution by sloshing and discuss its importance. We verify that the subcluster required to produce the observed cold fronts could be completely ram-pressure-stripped before reaching the Virgo centre, and discuss the conditions required for this to be achieved. Finally, we demonstrate that the bow shock of a fast galaxy passing the Virgo cluster at ~400 kpc distance also causes sloshing and leads to very similar cold front structures. The responsible galaxy would be located about 2 Mpc north of the Virgo centre. A possible candidate is M85.
Development of a fast electromagnetic beam blanker for compressed sensing in scanning transmission electron microscopy

The concept of compressed sensing was recently proposed to significantly reduce the electron dose in scanning transmission electron microscopy (STEM) while still maintaining the main features in the image. Here, an experimental setup based on an electromagnetic beam blanker placed in the condenser plane of a STEM is proposed. The beam blanker deflects the beam with a random pattern, while the scanning coils are moving the beam in the usual scan pattern. Experimental images at both the medium scale and high resolution are acquired and reconstructed based on a discrete cosine algorithm. The obtained results confirm that compressed sensing is highly attractive to limit beam damage in experimental STEM even though some remaining artifacts need to be resolved.
Evidence-Aware Multilingual Fake News Detection

Due to the rapid growth of the Internet and the subsequent rise of social media users, sharing information has become more flexible than ever before. This unrestricted freedom has also led to an increase in fake news. During the Covid-19 outbreak, fake news spread globally, negatively affecting authorities’ decisions and the health of individuals. As a result, governments, media agencies, and academics have established fact-checking units and developed automatic detection systems. Research approaches to verify the veracity of news focused largely on writing styles, propagation patterns, and building knowledge bases that serve as a reference for fact checking. However, little work has been done to assess the credibility of the source of the claim to be checked. This paper proposes a general framework for detecting fake news that uses external evidence to verify the veracity of online news in a multilingual setting. Search results from Google are used as evidence, and the claim is cross-checked with the top five search results. Additionally, we associate a vector of credibility scores with each evidence source based on the domain name and website reputation metrics. All of these components are combined to derive better predictions of the veracity of claims. Further, we analyze the claim-evidence entailment relationship and select supporting and refuting evidence to cross-check with the claim. The approach without selection components yields better detection performance. In this work, we consider as a case study Covid-19 related news. Our framework achieves an F1-score of 0.85 and 0.97 in distinguishing fake from true news on XFact and Constraint datasets respectively. With the achieved results, the proposed framework present a promising automatic fact checker for both early and late detection.
Interplay of waves and eddies in rotating stratified turbulence and the link with kinetic-potential energy partition

The interplay between waves and eddies in stably stratified rotating flows is investigated by means of world-class direct numerical simulations using up to 30723 grid points. Strikingly, we find that the shift from vortex- to wave-dominated dynamics occurs at a wave number kR which does not depend on the Reynolds number, suggesting that the partition of energy between wave and vortical modes is not sensitive to the development of turbulence at the smaller scales. We also show that kR is comparable to the wave number at which exchanges between kinetic and potential modes stabilize at close to equipartition, emphasizing the role of potential energy, as conjectured in the atmosphere and the oceans. Moreover, kR varies as the inverse of the Froude number as explained by the scaling prediction proposed, consistently with recent observations and modeling of the Mesosphere–Lower Thermosphere and of the ocean.
SEARCHING FOR X-RAY VARIABILITY IN THE GLITCHING ANOMALOUS X-RAY PULSAR 1E 1841−045 IN KES 73

Anomalous X-ray pulsars (AXPs) are now established to exhibit significant X-ray variability and be prolific glitchers, with some glitches being accompanied by large radiative changes. An open issue is whether AXP glitches are generically accompanied by radiative changes, relevant for understanding magnetar physical properties. Here we report on an analysis of archival X-ray data from the AXP 1E 1841−045, obtained between 1993 and 2007. This AXP, located in the center of the supernova remnant Kes 73, has exhibited three glitches between 2002 and 2007, as determined by RXTE monitoring since 1999. We have searched for evidence of phase-averaged flux variability that could be present if glitches in AXPs are usually accompanied by radiative changes. We find no evidence for glitch-correlated flux changes from this source after 1999, supporting the existence of radiatively silent glitches in AXPs.
A spectroscopic study of the globular Cluster NGC 4147

We present the abundance analysis for a sample of 18 red giant branch stars in the metal-poor globular cluster NGC 4147 based on medium and high resolution spectra. This is the first extensive spectroscopic study of this cluster. We derive abundances of C, N, O, Na, Mg, Al, Si, Ca, Ti, Cr, Fe, Ni, Y, Ba, and Eu. We find a metallicity of [Fe/H]=-1.84+-0.02 and an alpha-enhancement of +0.38+-0.05 (errors on the mean), typical of halo globular clusters in this metallicity regime. A significant spread is observed in the abundances of light elements C, N, O, Na, and Al. In particular we found a Na-O anti-correlation and Na-Al correlation. The cluster contains only 15% of stars that belong to the first generation (Na-poor and O-rich). This implies that it suffered a severe mass loss during its lifetime. Its [Ca/Fe] and [Ti/Fe] mean values agree better with the Galactic Halo trend than with the trend of extragalactic environments at the cluster metallicity. This possibly suggests that NGC 4147 is a genuine Galactic object at odd with what claimed by some author that proposed the cluster to be member of the Sagittarius dwarf galaxy. A anti-relation between the light s-process element Y and Na may also be present.
Nonlinear evolution of the baryon acoustic oscillation scale in alternative theories of gravity

The scale of baryon acoustic oscillations (BAO) imprinted in the matter power spectrum provides an almost-perfect standard ruler: it only suffers subpercent deviations from fixed comoving length due to nonlinear effects. We study the BAO shift in the large Horndeski class of gravitational theories and compute its magnitude in momentum space using second-order perturbation theory and a peak-background split. The standard prediction is affected by the modified linear growth, as well as by nonlinear gravitational effects that alter the mode-coupling kernel. For covariant Galileon models, we find a 14%--45% enhancement of the BAO shift with respect to standard gravity and a distinct time evolution depending on the parameters. Despite the larger values, the shift remains well below the forecasted precision of next-generation galaxy surveys. Models that produce significant BAO shift would cause large redshift-space distortions or affect the bispectrum considerably. Our computation therefore validates the use of the BAO scale as a comoving standard ruler for tests of general dark energy models.
Modulated nematic structures and chiral symmetry breaking in 2D

ABSTRACT We have studied the properties of biaxial particles interacting via an anisotropic pair potential, involving second-rank quadrupolar and third-rank octupolar coupling terms, using Monte Carlo simulation. The particles occupy the sites of a 2D square lattice and the interactions are restricted to nearest neighbours. The system exhibits spontaneous chiral symmetry breaking from an isotropic phase to a chiral modulated nematic phase, composed of ambidextrous chiral domains. When twofold axes of quadrupolar and octupolar tensors coincide this modulated phase appears to be the ambidextrous cholesteric phase with pitch comparable to a few lattice spacings. The associated phase transition is first order. Graphical Abstract
COSMIC REIONIZATION ON COMPUTERS: THE FAINT END OF THE GALAXY LUMINOSITY FUNCTION

Using numerical cosmological simulations completed under the “Cosmic Reionization On Computers” project, I explore theoretical predictions for the faint end of the galaxy UV luminosity functions at . A commonly used Schechter function approximation with the magnitude cut at provides a reasonable fit to the actual luminosity function of simulated galaxies. When the Schechter functional form is forced on the luminosity functions from the simulations, the magnitude cut is found to vary between −12 and −14 with a mild redshift dependence. An analytical model of reionization from Madau et al., as used by Robertson et al., provides a good description of the simulated results, which can be improved even further by adding two physically motivated modifications to the original Madau et al. equation.
Automated Quantitative Analysis of Anterior Segment Inflammation Using Swept-Source Anterior Segment Optical Coherence Tomography: A Pilot Study

Background: The aim of this study is to develop an automated evaluation of anterior chamber (AC) cells in uveitis using anterior segment (AS) optical coherence tomography (OCT) images. Methods: We analyzed AS swept-source (SS)-OCT (CASIA 2) images of 31 patients (51 eyes) with uveitis using image analysis software (Python). An automated algorithm was developed to detect cellular spots corresponding to hyper-reflective spots in the AC, and the correlation with Standardization of Uveitis Nomenclature (SUN) grading AC cells score was evaluated. The approximated AC grading value was calculated based on the logarithmic approximation curve between the number of cellular spots and the SUN grading score. Results: Among 51 eyes, cellular spots were automatically segmented in 48 eyes, whereas three eyes (all SUN grading AC cells score: 4+) with severe fibrin formation in the AC were removed by the automated algorithm. The AC cellular spots increased with an increasing SUN grading score (p < 0.001). The 48 eyes were split into training data (26 eyes) and test data (22 eyes). There was a significant correlation between the SUN grading score and the number of cellular spots in 26 eyes (rho: 0.843, p < 0.001). There was a significant correlation between the SUN grading score and the approximated grading value of 22 eyes based on the logarithmic approximation curve (rho: 0.774, p < 0.001). Leave-one-out cross-validation analysis demonstrated a significant correlation between the SUN grading score and the approximated grading value of 48 eyes (rho: 0.748, p < 0.001). Conclusions: This automated anterior AC cell analysis using AS SS-OCT showed a significant correlation with clinical SUN grading scores and provided SUN AC grading values as a continuous variable. Our findings suggest that automated grading of AC cells could improve the accuracy of a quantitative assessment of AC inflammation using AS-OCT images and allow the objective and rapid evaluation of anterior segment inflammation in uveitis. Further investigations on a large scale are required to validate this quantitative measurement of anterior segment inflammation in uveitic eyes.
STABILITY OF THE KEPLER-11 SYSTEM AND ITS ORIGIN

A significant fraction of Kepler systems are closely packed, largely coplanar, and circular. We study the stability of a six-planet system, Kepler-11, to gain insights on the dynamics and formation history of such systems. Using a technique called “frequency maps” as fast indicators of long-term stability, we explore the stability of the Kepler-11 system by analyzing the neighborhood space around its orbital parameters. Frequency maps provide a visual representation of chaos and stability, and their dependence on orbital parameters. We find that the current system is stable, but lies within a few percent of several dynamically dangerous two-body mean-motion resonances. Planet eccentricities are restricted below a small value, ∼0.04, for long-term stability, but planet masses can be more than twice their reported values (thus allowing for the possibility of mass loss by past photoevaporation). Based on our frequency maps, we speculate on the origin of instability in closely packed systems. We then proceed to investigate how the system could have been assembled. The stability constraints on Kepler-11 (mainly eccentricity constraints) suggest that if the system were assembled in situ, a dissipation mechanism must have been at work to neutralize the eccentricity excitation. On the other hand, if migration was responsible for assembling the planets, there has to be little differential migration among the planets to avoid them either getting trapped into mean motion resonances, or crashing into each other.