Miracle-dz/UniFAR-FTUs huggingface dataset:
A New Photometric Technique for the Joint Selection of Star-forming and Passive Galaxies at 1.4 ≲ z ≲ 2.5

A simple two-color selection based on B-, z-, and K-band photometry is proposed for culling galaxies at 1.4 ≲ z ≲ 2.5 in K-selected samples and classifying them as star-forming or passive systems. The method is calibrated on the highly complete spectroscopic redshift database of the K20 survey, verified with simulations and tested on other data sets. Requiring BzK = (z - K)AB - (B - z)AB > -0.2 allows us to select actively star-forming galaxies at z ≳ 1.4, independently of their dust reddening. On the other hand, objects with BzK < -0.2 and (z - K)AB > 2.5 colors include passively evolving galaxies at z ≳ 1.4, often with spheroidal morphologies. Simple recipes to estimate the reddening, star formation rates (SFRs), and masses of BzK-selected galaxies are derived and are calibrated on K < 20 galaxies. These K < 20 galaxies have typical stellar masses of ~1011 M☉ and sky and volume densities of ~1 arcmin-2 and ~10-4 Mpc-3, respectively. Based on their UV (reddening-corrected), X-ray, and radio luminosities, the BzK-selected star-forming galaxies with K < 20 turn out to have average SFR ≈ 200 M☉ yr-1 and median reddening E(B - V) ~ 0.4. This SFR is a factor of 10 higher than that of z ~ 1 dusty extremely red objects, and a factor of 3 higher than found for z ~ 2 UV-selected galaxies, both at similar K limits. Besides missing the passively evolving galaxies, the UV selection appears to miss some relevant fraction of the z ~ 2 star-forming galaxies with K < 20, and hence of the (obscured) SFR density at this redshift. The high SFRs and masses add to other existing evidence that these z = 2 star-forming galaxies may be among the precursors of z = 0 early-type galaxies. A V/Vmax test suggests that such a population may be increasing in number density with increasing redshift. Theoretical models cannot reproduce simultaneously the space density of both passively evolving and highly star-forming galaxies at z = 2. In view of Spitzer Space Telescope observations, an analogous technique based on RJL photometry is proposed to complement the BzK selection and to identify massive galaxies at 2.5 ≲ z ≲ 4.0. By selecting passively evolving galaxies as well as actively star-forming galaxies (including strongly dust-reddened ones), these color criteria should help in completing the census of the stellar mass and of the SFR density at high redshift.
Interbank Trading in a Segmented OTC Market∗

We present a core-periphery model of trading in the overnight interbank market. We model periods of crises as an increase in the number of peripheral banks that lose access to core dealers, resulting in segmentation between core and peripheral markets. Our model implies that such an increase in segmentation raises (i) the market power of periphery banks connected to the core, (ii) the dispersion of rates in the interbank market, and (iii) ineffi cient recourse to the central bank standing facilities. We argue that these implications are consistent with stylised facts about the interbank market and propose new predictions about trading in a segmented OTC market.
Atomic and molecular gas in IllustrisTNG galaxies at low redshift

We have recently developed a post-processing framework to estimate the abundance of atomic and molecular hydrogen (H i and H2, respectively) in galaxies in large-volume cosmological simulations. Here we compare the H i and H2 content of IllustrisTNG galaxies to observations. We mostly restrict this comparison to z ≈ 0 and consider six observational metrics: the overall abundance of H i and H2, their mass functions, gas fractions as a function of stellar mass, the correlation between H2 and star formation rate, the spatial distribution of gas, and the correlation between gas content and morphology. We find generally good agreement between simulations and observations, particularly for the gas fractions and the H i mass–size relation. The H2 mass correlates with star formation rate as expected, revealing an almost constant depletion time that evolves up to z = 2 as observed. However, we also discover a number of tensions with varying degrees of significance, including an overestimate of the total neutral gas abundance at z = 0 by about a factor of 2 and a possible excess of satellites with no or very little neutral gas. These conclusions are robust to the modelling of the H i/H2 transition. In terms of their neutral gas properties, the IllustrisTNG simulations represent an enormous improvement over the original Illustris run. All data used in this paper are publicly available as part of the IllustrisTNG data release.
ZOMG - III. The effect of halo assembly on the satellite population

We use zoom hydrodynamical simulations to investigate the properties of satellites within galaxy-sized dark-matter haloes with different assembly histories. We consider two classes of haloes at redshift $z=0$: `stalled' haloes that assembled at $z>1$ and `accreting' ones that are still forming nowadays. Previously, we showed that the stalled haloes are embedded within thick filaments of the cosmic web while the accreting ones lie where multiple thin filaments converge. We find that satellites in the two classes have both similar and different properties. Their mass spectra, radial count profiles, baryonic and stellar content, and the amount of material they shed are indistinguishable. However, the mass fraction locked in satellites is substantially larger for the accreting haloes as they experience more mergers at late times. The largest difference is found in the satellite kinematics. Substructures fall towards the accreting haloes along quasi-radial trajectories whereas an important tangential velocity component is developed, before accretion, while orbiting the filament that surrounds the stalled haloes. Thus, the velocity anisotropy parameter of the satellites ($\beta$) is positive for the accreting haloes and negative for the stalled ones. This signature enables us to tentatively categorize the Milky Way halo as stalled based on a recent measurement of $\beta$. Half of our haloes contain clusters of satellites with aligned orbital angular momenta corresponding to flattened structures in space. These features are not driven by baryonic physics and are only found in haloes hosting grand-design spiral galaxies, independently of their assembly history.
A Multi-ringed, Modestly Inclined Protoplanetary Disk around AA Tau

AA Tau is the archetype for a class of stars with a peculiar periodic photometric variability thought to be related to a warped inner disk structure with a nearly edge-on viewing geometry. We present high resolution (∼0.″2) ALMA observations of the 0.87 and 1.3 mm dust continuum emission from the disk around AA Tau. These data reveal an evenly spaced three-ringed emission structure, with distinct peaks at 0. ″34, 0. ″66, and 0. ″99, all viewed at a modest inclination of 59. °1 ± 0. °3 (decidedly not edge-on). In addition to this ringed substructure, we find non-axisymmetric features, including a “bridge” of emission that connects opposite sides of the innermost ring. We speculate on the nature of this “bridge” in light of accompanying observations of HCO+ and 13CO (J = 3–2) line emission. The HCO+ emission is bright interior to the innermost dust ring, with a projected velocity field that appears rotated with respect to the resolved disk geometry, indicating the presence of a warp or inward radial flow. We suggest that the continuum bridge and HCO+ line kinematics could originate from gap-crossing accretion streams, which may be responsible for the long-duration dimming of optical light from AA Tau.
The Event Horizon General Relativistic Magnetohydrodynamic Code Comparison Project

Recent developments in compact object astrophysics, especially the discovery of merging neutron stars by LIGO, the imaging of the black hole in M87 by the Event Horizon Telescope, and high- precision astrometry of the Galactic Center at close to the event horizon scale by the GRAVITY experiment motivate the development of numerical source models that solve the equations of general relativistic magnetohydrodynamics (GRMHD). Here we compare GRMHD solutions for the evolution of a magnetized accretion flow where turbulence is promoted by the magnetorotational instability from a set of nine GRMHD codes: Athena++, BHAC, Cosmos++, ECHO, H-AMR, iharm3D, HARM-Noble, IllinoisGRMHD, and KORAL. Agreement among the codes improves as resolution increases, as measured by a consistently applied, specially developed set of code performance metrics. We conclude that the community of GRMHD codes is mature, capable, and consistent on these test problems.
Modeling of Periodic Array of Cut-through Slits with Periodic Surface Conductivity at the Interfaces of an Anisotropic Medium

A periodic arrangement of one-dimensional slits carved in perfect electric conductor is investigated and an equivalent model based on the effective medium theory is derived. The proposed model is no longer fully homogeneous and features periodic surface conductivity on its upper and lower interfaces. Therefore, and in sheer contrast to all the previous attempts that were successful in mimicking only the zeroth-order diffracted waves, it is capable of emulating both specular and non-specular diffraction orders. The parameters of the equivalent model are found by comparing the scattered waves of the proposed model against those of the original structure obtained by invoking the rigorous mode matching technique based on the single mode approximation inside the slits. The proposed model is characterized by diagonal anisotropic permittivity and permeability tensors together with a periodic surface conductivity at the interfaces of the metallic grating and the ambient environment. The accuracy of the model is verified by the full-wave simulations. The proposed approach might be useful for devising applications which work based on the characteristics of higher Floquet orders.
Whittaker vector, Wheeler-DeWitt equation, and the gravity dual of conformal quantum mechanics

We study the energy representation of conformal quantum mechanics as the Whittaker vector without specifying classical Lagrangian. We show that a generating function of expectation values among two excited states of the dilatation operator in conformal quantum mechanics is a solution to the Wheeler-DeWitt equation and it corresponds to the AdS2 partition function evaluated as the minisuperspace wave function in Liouville field theory. We also show that the dilatation expectation values in conformal quantum mechanics lead to the asymptotic smoothed counting function of the Riemann zeros.
Geometric structure of pseudo-plane quadratic flows

Quadratic flows have the unique property of uniform strain and are commonly used in turbulence modeling and hydrodynamic analysis. While previous applications focused on two-dimensional homogeneous fluid, this study examines the geometric structure of three-dimensional quadratic flows in stratified fluid by solving a steady-state pseudo-plane flow model. The complete set of exact solutions reveals that steady quadratic flows have an invariant conic type in the non-rotating frame and a non-rotatory vertical structure in the rotating frame. Three baroclinic solutions with vertically non-aligned formulation disprove an earlier conjecture. All elliptic and hyperbolic solutions, except for the inertial ones, exhibit vertical concentricity. The rich geometry of quadratic flows stands in contrast to the depleted geometry of high-degree polynomial flows. A paradox in the steady solutions of shallow-water reduced-gravity models is also explained.
Stability of rotating shear flows in shallow water

Asymptotic methods are used to determine the dispersion equation for disturbances of rotating parallel flows in shallow water. From this equation the unstable modes and their growth rates are determined. The solution involves seven asymptotic expansions which are matched together. The results supplement and extend those which have been obtained previously using numerical methods by Griffiths, Killworth & Stern (1982) and by Hayashi & Young (1987).
Group galaxy number density profiles far out: Is the ‘one-halo’ term NFW out to >10 virial radii?

While the density profiles (DPs) of $\Lambda$CDM haloes obey the NFW law out to roughly one virial radius, $r_{\rm vir}$, the structure of their outer parts is still poorly understood, since the 1-halo term describing the halo itself is dominated by the 2-halo term representing the other haloes picked up. Using a semi-analytical model, we measure the real-space `1-halo' number DP of groups out to $20\,r_{\rm vir}$ by assigning each galaxy to its nearest group with mass above $M_{\rm a}$, in units of the group $r_{\rm vir}$. If $M_{\rm a}$ is small (large), the outer DP of groups falls rapidly (slowly). We find that there is an optimal $M_{\rm a}$ for which the stacked DP resembles the NFW model to $0.1$ dex accuracy out to $\simeq 13\,r_{\rm vir}$. We find similar long-range NFW surface DPs (out to $\simeq 10\,r_{\rm vir}$) in the SDSS observations using a galaxy assignment scheme that combines the non-linear virialized regions of groups with their linear outer parts. The optimal $M_{\rm a}$ scales as the minimum mass of the groups that are stacked to the power $0.25-0.3$. Our results suggest that the NFW model does not solely originate from violent relaxation. Moreover, populating haloes with galaxies using HOD models must proceed out to larger radii than usually done.
Scattering Cancellation-Based Cloaking for the Maxwell-Cattaneo Heat Waves

In this work we theoretically propose scattering cancellation-based cloaks for heat waves that obey the Maxwell-Cattaneo equation. The proposed cloaks possess carefully tailored diffusivity to cancel the dipole scattering from the object that they surround, and thus can render a small object invisible in the near and far fields, as demonstrated by full-wave finite-element simulations. Mantle heat cloaking is further analyzed and proposed to simplify the design and bring this cloaking technology one step closer to its practical implementation, with promising applications in nanoelectronics and defense related applications.
Gauge Fixing and the Semiclassical Interpretation of Quantum Cosmology

Abstract We make a critical review of the semiclassical interpretation of quantum cosmology and emphasise that it is not necessary to consider that a concept of time emerges only when the gravitational field is (semi)classical. We show that the usual results of the semiclassical interpretation and its generalisation known as the Born–Oppenheimer approach to quantum cosmology can be obtained by gauge fixing, both at the classical and quantum levels. By “gauge fixing,” we mean a particular choice of the time coordinate, which determines the arbitrary Lagrange multiplier that appears in Hamilton’s equations. In the quantum theory, we adopt a tentative definition of the (Klein–Gordon) inner product, which is positive definite for solutions of the quantum constraint equation found via an iterative procedure that corresponds to a weak coupling expansion in powers of the inverse Planck mass. We conclude that the wave function should be interpreted as a state vector for both gravitational and matter degrees of freedom, the dynamics of which is unitary with respect to the chosen inner product and time variable.
Quenching Low-mass Satellite Galaxies: Evidence for a Threshold ICM Density

We compile a sample of Sloan Digital Sky Survey (SDSS) galaxy clusters with high-quality Chandra X-ray data to directly study the influence of the dense intracluster medium (ICM) on the quenching of satellite galaxies. We study the quenched fractions of satellite galaxies as a function of ICM density for low- (109 ≲ M⋆ ≲ 1010 M⊙), intermediate- (1010 ≲ M⋆ ≲ 1010.5 M⊙), and high-mass (M⋆ ≳ 1010.5 M⊙) satellite galaxies with >3000 satellite galaxies across 24 low-redshift (z < 0.1) clusters. For low-mass galaxies we find evidence for a broken power-law trend between satellite quenched fraction and local ICM density. The quenched fraction increases modestly at ICM densities below a threshold before increasing sharply beyond this threshold toward the cluster center. We show that this increase in quenched fraction at high ICM density is well matched by a simple, analytic model of ram pressure stripping. These results are consistent with a picture where low-mass cluster galaxies experience an initial, slow-quenching mode driven by steady gas depletion, followed by rapid quenching associated with ram pressure of cold-gas stripping near (one-quarter of the virial radius, on average) the cluster center.
Probability distribution for omega in open universe inflation

The problem of making predictions in eternally inflating universe that thermalizes by bubble nucleation is considered. A recently introduced regularization procedure is applied to find the probability distribution for the ensemble of thermalized bubbles. The resulting probabilities are shown to be independent of the choice of the time parametrization. This formalism is applied to models of open ``hybrid'' inflation with $\Omega <1$. Depending on the parameters of the model, the probability distribution for $\Omega $ is found to have a peak either very close to $\Omega =1$, or at an intermediate value of $\Omega $ in the range $0.03\lesssim \Omega <1$.
Molecular dynamics studies of granular flow through an aperture

Molecular dynamics methods are used to study two-dimensional gravity-driven granular flow through a horizontal aperture. Two distinct approaches to modeling the granular particles are studied. ~a! Circular particles subject to a strongly repulsive short-range interaction, together with normal and tangential frictional damping forces. ~b! Rigid nonconvex particles, each consisting of disks arranged as an equilateral triangle, suitably spaced to provide a tangible indentation along each edge; the same repulsive interactions between disks in different grains and normal frictional damping forces are incorporated, but transverse damping is omitted, with the model relying on grain shape to resist sliding motion. In order to allow accurate measurements under steady-state conditions, a continuous-feed approach is adopted, in which grains exiting through the hole are returned to the top of the material in the container. For both models the output flow is measured as a function of aperture size, and the observed behavior is compared with previous theoretical and experimental results. Tests of the degree to which the models reproduce the depth independence of the flow are reported, and the influence of the container width and the nature of the walls are studied. The depth dependence of the pressure, the local stress distribution, and the particle flow patterns are also examined. @S1063-651X~97! 05710-3#
Electronic structures of normal and inverse spinel ferrites from first principles

We apply the self-interaction corrected local spin density approximation to study the electronic structure and magnetic properties of the spinel ferrites $\mathrm{Mn}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$, ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$, $\mathrm{Co}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$, and $\mathrm{Ni}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$. We concentrate on establishing the nominal valence of the transition metal elements and the ground state structure, based on the study of various valence scenarios for both the inverse and normal spinel structures for all the systems. For both structures we find all the studied compounds to be insulating, but with smaller gaps in the normal spinel scenario. On the contrary, the calculated spin magnetic moments and the exchange splitting of the conduction bands are seen to increase dramatically when moving from the inverse spinel structure to the normal spinel kind. We find substantial orbital moments for $\mathrm{Ni}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$ and $\mathrm{Co}{\mathrm{Fe}}_{2}{\mathrm{O}}_{4}$.
Magnetic Field Control of Optical Transmission and Narrow Linewidth Superradiant Lasing by Strontium Atoms

We study the magnetic field controlled optical transmission observed in [Phys. Rev. Lett. 118, 263601 (2017)] with ultra-cold ${}^{88} {\rm Sr}$ atoms trapped in a one-dimensional optical lattice inside an optical cavity. We show that this phenomenon can be understood with a Jaynes-Cumming-like model for the atoms with two Zeeman-split excited states. This model yields three peaks in the transmission spectrum associated with three singly excited dressed states. The transmission is controlled by adjusting the photonic components in the dressed states via the Zeeman splitting of the atomic levels. If the atomic ensemble is incoherently pumped, lasing can be achieved in a superradiant crossover regime. Without the magnetic field the lasing relies on bright dressed states featuring a spectrum with line-width down to $5$ kHz. However, in the presence of the magnetic field, the lasing relies on the dressed states, which are originally uncoupled but acquire photonic component due to the Zeeman splitting, and can yield a spectrum with line-width down to $2$ Hz.
The Hubble Space Telescope Quasar Absorption Line Key Project: The Unusual Absorption-Line System in the Spectrum of PG 2302+029—Ejected or Intervening?

We report the discovery of a high-ionization broad absorption line system at a redshift of zabs = 0.695 in the spectrum of the zem = 1.052 radio-quiet quasar PG 2302+029. Broad absorption with FWHM from 3000 to 5000 km s-1 is detected from C IV, N V, and O VI in Hubble Space Telescope (HST) Faint Object Spectrograph spectra of the quasar. A narrow-line system (FWHM ~ 250 km s-1) at zabs = 0.7016 is resolved from the broad blend and includes absorption by Lyα and the C IV, N V, and O VI doublets. No absorption by low-ionization metal species (e.g., Si II and Mg II) is detected in the HST or ground-based spectra for either the broad or the narrow system. The centroids of the broad system lines are displaced by ~56,000 km s-1 to the blue of the quasar's broad emission lines. The reddest extent of the broad-line absorption is more than 50,000 km s-1 from the quasar. The properties of this system are unprecedented, whether it is an intervening or an ejected system.
Enhanced cosmological GRB rates and implications for cosmogenic neutrinos

Gamma-ray bursts, which are among the most violent events in the Universe, are one of the few viable candidates to produce ultra high-energy cosmic rays. Recently, observations have revealed that GRBs generally originate from metal-poor, low-luminosity galaxies and do not directly trace cosmic star formation, as might have been assumed from their association with core-collapse supernovae. Several implications follow from these findings. The redshift distribution of observed GRBs is expected to peak at higher redshift (compared to cosmic star formation), which is supported by the mean redshift of the Swift GRB sample, {approx}3. If GRBs are, in fact, the source of the observed UHECR, then cosmic-ray production would evolve with redshift in a stronger fashion than has been previously suggested. This necessarily leads, through the GZK process, to an enhancement in the flux of cosmogenic neutrinos, providing a near-term approach for testing the gamma-ray burst-cosmic-ray connection with ongoing and proposed UHE neutrino experiments.