Miracle-dz/UniFAR-FTUs huggingface dataset:
GALAXIES IN X-RAY GROUPS. I. ROBUST MEMBERSHIP ASSIGNMENT AND THE IMPACT OF GROUP ENVIRONMENTS ON QUENCHING

Understanding the mechanisms that lead dense environments to host galaxies with redder colors, more spheroidal morphologies, and lower star formation rates than field populations remains an important problem. As most candidate processes ultimately depend on host halo mass, accurate characterizations of the local environment, ideally tied to halo mass estimates and spanning a range in halo mass and redshift, are needed. In this work, we present and test a rigorous, probabilistic method for assigning galaxies to groups based on precise photometric redshifts and X-ray-selected groups drawn from the COSMOS field. The groups have masses in the range 1013 ≲ M200c/M☉ ≲ 1014 and span redshifts 0 < z < 1. We characterize our selection algorithm via tests on spectroscopic subsamples, including new data obtained at the Very Large Telescope, and by applying our method to detailed mock catalogs. We find that our group member galaxy sample has a purity of 84% and completeness of 92% within . We measure the impact of uncertainties in redshifts and group centering on the quality of the member selection with simulations based on current data as well as future imaging and spectroscopic surveys. As a first application of our new group member catalog which will be made publicly available, we show that member galaxies exhibit a higher quenched fraction compared to the field at fixed stellar mass out to z ∼ 1, indicating a significant relationship between star formation and environment at group scales. We also address the suggestion that dusty star-forming galaxies in such groups may impact the high-ℓ power spectrum of the cosmic microwave background and find that such a population cannot explain the low power seen in recent Sunyaev–Zel'dovich measurements.
Decay of turbulence in a liquid metal duct flow with transverse magnetic field

Decay of honeycomb-generated turbulence in a duct with a static transverse magnetic field is studied via direct numerical simulations. The simulations follow the revealing experimental study of Sukoriansky et al. (Exp. Fluids, vol. 4 (1), 1986, pp. 11–16), in particular the paradoxical observation of high-amplitude velocity fluctuations, which exist in the downstream portion of the flow when the strong transverse magnetic field is imposed in the entire duct including the honeycomb exit, but not in other configurations. It is shown that the fluctuations are caused by the large-scale quasi-two-dimensional structures forming in the flow at the initial stages of the decay and surviving the magnetic suppression. Statistical turbulence properties, such as the energy decay curves, two-point correlations and typical length scales are computed. The study demonstrates that turbulence decay in the presence of a magnetic field is a complex phenomenon critically depending on the state of the flow at the moment the field is introduced.
Radius Inflation at Low Rossby Number in the Hyades Cluster

Radius inflation continues to be explored as a peculiar occurrence among magnetically active, low-mass stars. Recently, Somers & Stassun showed that radius inflation among low-mass stars in the young open cluster M45 (Pleiades Cluster) is correlated to the rotation rate: faster rotators are more inflated. Here we extend that work to a sample of 68 stars of the older open Hyades Cluster. We derive the stars’ spectral energy distributions to measure their bolometric fluxes. With spectroscopically defined Teff and Gaia distances we calculate stellar radii using the Stefan–Boltzmann relation. We find numerous stars that exhibit significant (3–4σ) radius inflation relative to a nominal cluster isochrone. We compare these results to that of the younger Pleiades and consider radius inflation as a function of open cluster evolution. We find that unlike the Pleiades, there is not a statistically significant correlation between radius inflation and stellar rotation period. However, we do find that most inflated stars have (rapid) rotational Rossby numbers of 0.1–0.2, such that the correlation of radius inflation with Rossby number is statistically significant at 99.98% confidence. Because the canonical rotation-activity relation of low-mass stars is understood to result from the connection between magnetic activity and surface convection, our results imply that magnetic activity within the convective layers of low-mass stars is what preferentially drives radius inflation.
Clustering of luminous red galaxies – IV. Baryon acoustic peak in the line-of-sight direction and a direct measurement of H(z)

We study the clustering of luminous red galaxies in the latest spectroscopic Sloan Digital Sky Survey data releases (DR), DR6 and DR7, which sample over 1 Gpc 3 h ―3 to z = 0.47. The two-point correlation function ξ(σ, π) is estimated as a function of perpendicular σ and line-of-sight π (radial) directions. We find significant detection of a peak at r ≃ 110 Mpc h ―1 , which shows as a circular ring in the σ―π plane. There is also significant evidence of a peak along the radial direction whose shape is consistent with its origination from the recombination-epoch baryon acoustic oscillations (BAO). A ξ (σ, π) model with no radial BAO peak is disfavoured at 3. 2σ, whereas a model with no magnification bias is disfavoured at 2σ. The radial data enable, for the first time, a direct measurement of the Hubble parameter H(z) as a function of redshift. This is independent of earlier BAO measurements which used the spherically averaged (monopole) correlation to constrain an integral of H(z). Using the BAO peak position as a standard ruler in the radial direction, we find H(z = 0.24) = 79.69 ± 2.32 (±1.29) km s ―1 Mpc ―1 for z = 0.15-0.30 and H(z = 0.43) = 86.45 ± 3.27 (±1.69) km s ―1 Mac ―1 for z = 0.40-0.47. The first error is a model-independent statistical estimation and the second accounts for systematics both in the measurements and in the model. For the full sample, z = 0.15-0.47, we find H(z = 0.34) = 83.80 ± 2.96 (±1.59) km s ―1 Mpc ―1 .
USING MEMBER GALAXY LUMINOSITIES AS HALO MASS PROXIES OF GALAXY GROUPS

Reliable halo mass estimation for a given galaxy system plays an important role in both cosmology and galaxy formation studies. Here we set out to find a way to improve halo mass estimation of those galaxy systems in which a limited number of brightest member galaxies have been observed. Using four mock galaxy samples constructed from semi-analytical formation models, the subhalo abundance matching method, and the conditional luminosity functions, respectively, we find that the luminosity gap between the brightest and the subsequent brightest member galaxies in a halo (group) can be used to reduce significantly the scatter in the halo mass estimation based on the luminosity of the brightest galaxy alone. Tests show that these corrections can significantly reduce the scatter in the halo mass estimations by ∼50% to ∼70% in massive halos depending on which member galaxies are considered. Compared to the traditional ranking method, we find that this method works better for groups with less than five members, or in observations with a very bright magnitude cutoff.
THE TW Hya DISK AT 870 μm: COMPARISON OF CO AND DUST RADIAL STRUCTURES

We present high-resolution (0.″3 = 16 AU), high signal-to-noise ratio Submillimeter Array observations of the 870 μm (345 GHz) continuum and CO J = 3 − 2 line emission from the protoplanetary disk around TW Hya. Using continuum and line radiative transfer calculations, these data and the multiwavelength spectral energy distribution are analyzed together in the context of simple two-dimensional parametric disk structure models. Under the assumptions of a radially invariant dust population and gas-to-dust mass ratio, we are unable to simultaneously reproduce the CO and dust observations with model structures that employ either a single, distinct outer boundary or a smooth (exponential) taper at large radii. Instead, we find that the distribution of millimeter-sized dust grains in the TW Hya disk has a relatively sharp edge near 60 AU, contrary to the CO emission (and optical/infrared scattered light) that extends to a much larger radius of at least 215 AU. We discuss some possible explanations for the observed radial distribution of millimeter-sized dust grains and the apparent CO-dust size discrepancy, and suggest that they may be hallmarks of substructure in the dust disk or natural signatures of the growth and radial drift of solids that might be expected for disks around older pre-main-sequence stars like TW Hya.
CONSTRAINING SUB-PARSEC BINARY SUPERMASSIVE BLACK HOLES IN QUASARS WITH MULTI-EPOCH SPECTROSCOPY. II. THE POPULATION WITH KINEMATICALLY OFFSET BROAD BALMER EMISSION LINES

A small fraction of quasars have long been known to show bulk velocity offsets (of a few hundred to thousands of km s−1) in the broad Balmer lines with respect to the systemic redshift of the host galaxy. Models to explain these offsets usually invoke broad-line region gas kinematics/asymmetry around single black holes (BHs), orbital motion of massive (∼sub-parsec (sub-pc)) binary black holes (BBHs), or recoil BHs, but single-epoch spectra are unable to distinguish between these scenarios. The line-of-sight (LOS) radial velocity (RV) shifts from long-term spectroscopic monitoring can be used to test the BBH hypothesis. We have selected a sample of 399 quasars with kinematically offset broad Hβ lines from the Sloan Digital Sky Survey (SDSS) Seventh Data Release quasar catalog, and have conducted second-epoch optical spectroscopy for 50 of them. Combined with the existing SDSS spectra, the new observations enable us to constrain the LOS RV shifts of broad Hβ lines with a rest-frame baseline of a few years to nearly a decade. While previous work focused on objects with extreme velocity offset (>103 km s−1), we explore the parameter space with smaller (a few hundred km s−1) yet significant offsets (99.7% confidence). Using cross-correlation analysis, we detect significant (99% confidence) radial accelerations in the broad Hβ lines in 24 of the 50 objects, of ∼10–200 km s−1 yr−1 with a median measurement uncertainty of ∼10 km s−1 yr−1, implying a high fraction of variability of the broad-line velocity on multi-year timescales. We suggest that 9 of the 24 detections are sub-pc BBH candidates, which show consistent velocity shifts independently measured from a second broad line (either Hα or Mg ii) without significant changes in the broad-line profiles. Combining the results on the general quasar population studied in Paper I, we find a tentative anti-correlation between the velocity offset in the first-epoch spectrum and the average acceleration between two epochs, which could be explained by orbital phase modulation when the time separation between two epochs is a non-negligible fraction of the orbital period of the motion causing the line displacement. We discuss the implications of our results for the identification of sub-pc BBH candidates in offset-line quasars and for the constraints on their frequency and orbital parameters.
HD 35502: a hierarchical triple system with a magnetic B5IVpe primary

We present our analysis of HD~35502 based on high- and medium-resolution spectropolarimetric observations. Our results indicate that the magnetic B5IVsnp star is the primary component of a spectroscopic triple system and that it has an effective temperature of $18.4\pm0.6\,{\rm kK}$, a mass of $5.7\pm0.6\,M_\odot$, and a polar radius of $3.0^{+1.1}_{-0.5}\,R_\odot$. The two secondary components are found to be essentially identical A-type stars for which we derive effective temperatures ($8.9\pm0.3\,{\rm kK}$), masses ($2.1\pm0.2\,M_\odot$), and radii ($2.1\pm0.4\,R_\odot$). We infer a hierarchical orbital configuration for the system in which the secondary components form a tight binary with an orbital period of $5.66866(6)\,{\rm d}$ that orbits the primary component with a period of over $40\,{\rm yrs}$. Least-Squares Deconvolution (LSD) profiles reveal Zeeman signatures in Stokes $V$ indicative of a longitudinal magnetic field produced by the B star ranging from approximately $-4$ to $0\,{\rm kG}$ with a median uncertainty of $0.4\,{\rm kG}$. These measurements, along with the line variability produced by strong emission in H$\alpha$, are used to derive a rotational period of $0.853807(3)\,{\rm d}$. We find that the measured $v\sin{i}=75\pm5\,{\rm km\,s}^{-1}$ of the B star then implies an inclination angle of the star's rotation axis to the line of sight of $24^{+6}_{-10}\degree$. Assuming the Oblique Rotator Model, we derive the magnetic field strength of the B star's dipolar component ($14^{+9}_{-3}\,{\rm kG}$) and its obliquity ($63\pm13\degree$). Furthermore, we demonstrate that the calculated Alfven radius ($41^{+17}_{-6}\,R_\ast$) and Kepler radius ($2.1^{+0.4}_{-0.7}\,R_\ast$) place HD~35502's central B star well within the regime of centrifugal magnetosphere-hosting stars.
SuperNNova: an open-source framework for Bayesian, neural network-based supernova classification

We introduce SuperNNova, an open-source supernova photometric classification framework that leverages recent advances in deep neural networks. Our core algorithm is a recurrent neural network (RNN) that is trained to classify light curves using only photometric information. Additional information such as host-galaxy redshift can be incorporated to improve performance. We evaluate our framework using realistic supernova simulations that include survey detection. We show that our method, for the type Ia versus non-Ia supernova classification problem, reaches accuracies greater than 96.92 ± 0.09 without any redshift information and up to 99.55 ± 0.06 when redshift, either photometric or spectroscopic, is available. Further, we show that our method attains unprecedented performance for the classification of incomplete light curves, reaching accuracies >86.4 ± 0.1 (>93.5 ± 0.8) without host-galaxy redshift (with redshift information) 2 d before maximum light. In contrast with previous methods, there is no need for time-consuming feature engineering and we show that our method scales to very large data sets with a modest computing budget. In addition, we investigate often neglected pitfalls of machine learning algorithms. We show that commonly used algorithms suffer from poor calibration and overconfidence on out-of-distribution samples when applied to supernova data. We devise extensive tests to estimate the robustness of classifiers and cast the learning procedure under a Bayesian light, demonstrating a much better handling of uncertainties. We study the benefits of Bayesian RNNs for SN Ia cosmology. Our code is open sourced and available on github1.
Thermodynamics of Micro- and Nano-Systems Driven by Periodic Temperature Variations

We introduce a general framework for analyzing the thermodynamics of small systems that are driven by both a periodic temperature variation and some external parameter modulating their energy. This set-up covers, in particular, periodic micro and nano-heat engines. In a first step, we show how to express total entropy production by properly identified time-independent affinities and currents without making a linear response assumption. In linear response, kinetic coefficients akin to Onsager coefficients can be identified. Specializing to a Fokker-Planck type dynamics, we show that these coefficients can be expressed as a sum of an adiabatic contribution and one reminiscent of a Green-Kubo expression that contains deviations from adiabaticity. Furthermore, we show that the generalized kinetic coefficients fulfill an Onsager-Casimir type symmetry tracing back to microscopic reversibility. This symmetry allows for non-identical off-diagonal coefficients if the driving protocols are not symmetric under time-reversal. We then derive a novel constraint on the kinetic coefficients that is sharper than the second law and provides an efficiency-dependent bound on power. As one consequence, we can prove that the power vanishes at least linearly when approaching Carnot efficiency. We illustrate our general framework by explicitly working out the paradigmatic case of a Brownian heat engine realized by a colloidal particle in a time-dependent harmonic trap subject to a periodic temperature profile. This case study reveals inter alia that our new general bound on power is asymptotically tight.
THE HALO OCCUPATION DISTRIBUTION OF SDSS QUASARS

We present an estimate of the projected two-point correlation function (2PCF) of quasars in the Sloan Digital Sky Survey (SDSS) over the full range of one- and two-halo scales, 0.02 h −1 Mpc < rp < 120 h −1 Mpc. This was achieved by combining data from SDSS DR7 on large scales and Hennawi et al. (with appropriate statistical corrections) on small scales. Our combined clustering sample is the largest spectroscopic quasar clustering sample to date, containing ∼48, 000 quasars in the redshift range 0.4 ≲ z ≲ 2.5 with median redshift 1.4. We interpret these precise 2PCF measurements within the halo occupation distribution (HOD) framework and constrain the occupation functions of central and satellite quasars in dark matter halos. In order to explain the small-scale clustering, the HOD modeling requires that a small fraction of z ∼ 1.4 quasars, f sat = (7.4 ± 1.4) × 10−4, be satellites in dark matter halos. At z ∼ 1.4, the median masses of the host halos of central and satellite quasars are constrained to be M cen = 4.1+0.3 − 0.4 × 1012 h −1 M ☉ and M sat = 3.6+0.8 − 1.0 × 1014 h −1 M ☉, respectively. To investigate the redshift evolution of the quasar-halo relationship, we also perform HOD modeling of the projected 2PCF measured by Shen et al. for SDSS quasars with median redshift 3.2. We find tentative evidence for an increase in the mass scale of quasar host halos—the inferred median mass of halos hosting central quasars at z ∼ 3.2 is M cen = 14.1+5.8 − 6.9 × 1012 h −1 M ☉. The cutoff profiles of the mean occupation functions of central quasars reveal that quasar luminosity is more tightly correlated with halo mass at higher redshifts. The average quasar duty cycle around the median host halo mass is inferred to be f q = 7.3+0.6 − 1.5 × 10−4 at z ∼ 1.4 and f q = 8.6+20.4 − 7.2 × 10−2 at z ∼ 3.2. We discuss the implications of our results for quasar evolution and quasar–galaxy co-evolution.
Radio haloes from simulations and hadronic models - II. The scaling relations of radio haloes

We use results from a constrained, cosmological magnetohydrodynamic (MHD) simulation of the Local Universe to predict radio haloes and their evolution for a volume-limited set of galaxy clusters and compare to current observations. The simulated magnetic field inside the clusters is a result of turbulent amplification within them, with the magnetic seed originating from starburst-driven, galactic outflows. We evaluate three models, where we choose different normalizations for the cosmic ray proton population within clusters. Similar to our previous analysis of the Coma cluster, the radial profile and the morphological properties of observed radio haloes cannot be reproduced, even with a radially increasing energy fraction within the cosmic ray proton population. Scaling relations between X-ray luminosity and radio power can be reproduced by all models; however all models fail in the prediction of clusters with no radio emission. Also the evolutionary tracks of our largest clusters in all models fail to reproduce the observed bi-modality in radio luminosity. This provides additional evidence that the framework of hadronic, secondary models is disfavoured to reproduce the large-scale diffuse radio emission of galaxy clusters. We also provide predictions for the unavoidable emission of γ-rays from the hadronic models for the full cluster set. None of such secondary models is yet excluded by the observed limits in γ-ray emission, emphasizing that large-scale diffuse radio emission is a powerful tool to constrain the amount of cosmic ray protons in galaxy clusters.
Ultraviolet variability of quasars: dependence on the accretion rate

Aims. Although the variability in the ultraviolet and optical domain is one of the major characteristics of quasars, the dominant underlying mechanisms are still poorly understood. There is a broad consensus on the relationship between the strength of the variability and such quantities as time-lag, wavelength, luminosity, and redshift. However, evidence on a dependence on the fundamental parameters of the accretion process is still inconclusive. This paper is focused on the correlation between the ultraviolet quasar long-term variability and the accretion rate. Methods. We compiled a catalogue of about 4000 quasars including individual estimators for the variability strength derived from the multi-epoch photometry in the SDSS Stripe 82, virial black hole masses M derived from the Mgii line, and mass accretion rates ˙ M from the Davis-Laor scaling relation. Several statistical tests were applied to evaluate the correlations of the variability with luminosity, mass, Eddington ratio, and accretion rate. Results. We confirm the existence of significant anti-correlations between the variability estimator V and the accretion rate ˙ M, the Eddington ratio ", and the bolometric luminosity Lbol, respectively. The Eddington ratio is tightly correlated with ˙ M. A weak, statistically not significant positive trend is indicated for the dependence of V on M. As a side product, we find a strong correlation of the radiative e ciency with M in our sample. We show via numerical simulations that this trend is most likely produced by selection e ects in combination with the mass errors and the use of the scaling relation for ˙ M. The anti-correlations of V with ˙ M, ", and Lbol cannot be explained in such a way. The strongest anti-correlation is found between V and ˙ M. However, it is di cult to decide which of the quantities L;", and ˙ M is intrinsically correlated with V and which of the observed correlations of V are produced by the L " ˙ M relation. A V ˙ M anti-correlation is qualitatively expected for the strongly inhomogeneous accretion disks. We argue that the observed amplitudes of the variability at far UV wavelengths, the stochastic nature of variability, and the variability time-scales are not adequately explained by the simple multi-temperature black-body model of a standard disk and suggest to check whether the strongly inhomogeneous disk model is capable of reproducing these observations better.
Mach's principle and higher‐dimensional dynamics

We briefly discuss the current status of Mach's principle in general relativity and point out that its last vestige, namely, the gravitomagnetic field associated with rotation, has recently been measured for the earth in the GP‐B experiment. Furthermore, in his analysis of the foundations of Newtonian mechanics, Mach provided an operational definition for inertial mass and pointed out that time and space are conceptually distinct from their operational definitions by means of masses. Mach recognized that this circumstance is due to the lack of any a priori connection between the inertial mass of a body and its Newtonian state in space and time. One possible way to improve upon this situation in classical physics is to associate mass with an extra dimension. Indeed, Einstein's theory of gravitation can be locally embedded in a Ricci‐flat 5D manifold such that the 4D energy‐momentum tensor appears to originate from the existence of the extra dimension. An outline of such a 5D Machian extension of Einstein's general relativity is presented.