Miracle-dz/UniFAR-FTUs huggingface dataset:
STAR FORMATION AND UV COLORS OF THE BRIGHTEST CLUSTER GALAXIES IN THE REPRESENTATIVE XMM-NEWTON CLUSTER STRUCTURE SURVEY

We present UV broadband photometry and optical emission-line measurements for a sample of 32 brightest cluster galaxies (BCGs) in clusters of the Representative XMM-Newton Cluster Structure Survey (REXCESS) with z = 0.06–0.18. The REXCESS clusters, chosen to study scaling relations in clusters of galaxies, have X-ray measurements of high quality. The trends of star formation and BCG colors with BCG and host properties can be investigated with this sample. The UV photometry comes from the XMM-Newton Optical Monitor, supplemented by existing archival Galaxy Evolution Explorer photometry. We detected Hα and forbidden line emission in seven (22%) of these BCGs, in optical spectra obtained using the Southern Astrophysical Research Goodman spectrograph. All of these emission-line BCGs occupy clusters classified as cool cores (CCs) based on the central cooling time in the cluster core, for an emission-line incidence rate of 70% for BCGs in REXCESS CC clusters. Significant correlations between the Hα equivalent widths, excess UV production in the BCG, and the presence of dense, X-ray bright intracluster gas with a short cooling time are seen, including the fact that all of the Hα emitters inhabit systems with short central cooling times and high central intracluster medium densities. Estimates of the star formation rates based on Hα and UV excesses are consistent with each other in these seven systems, ranging from 0.1to8 solar masses per year. The incidence of emission-line BCGs in the REXCESS sample is intermediate, somewhat lower than in other X-ray-selected samples (∼35%), and somewhat higher than but statistically consistent with optically selected, slightly lower redshift BCG samples (∼10%–15%). The UV–optical colors (UVW1 − R ∼4.7 ± 0.3) of REXCESS BCGs without strong optical emission lines are consistent with those predicted from templates and observations of ellipticals dominated by old stellar populations. We see no trend in UV–optical colors with optical luminosity, R–K color, X-ray temperature, redshift, or offset between X-ray centroid and X-ray peak (〈w〉). The lack of such trends in these massive galaxies, particularly the ones lacking emission lines, suggests that the proportion of UV-emitting (200–300 nm) stars is insensitive to galaxy mass, cluster mass, cluster relaxation, and recent evolution, over the range of this sample.
Incoherent thermal transport from dirty black holes

We study thermal transport in strongly disordered, strongly interacting quantum field theories without quasiparticles using gauge-gravity duality. We analyze linear perturbations of black holes with broken translational symmetry in Einstein-Maxwell-dilaton theories of gravity. Using general geometric arguments in the bulk, we derive bounds on thermal conductivity for the dual disordered field theories in one and two spatial dimensions. In the latter case, the thermal conductivity is always non-zero at finite temperature, so long as the dilaton potential is bounded from below. Hence, generic holographic models make non-trivial predictions about the thermal conductivity in a strongly disordered, strongly coupled metal in two spatial dimensions.
The first full orbit of η Carinae seen by Fermi

Aims. The binary system η Carinae has completed its first 5.54 y orbit since the beginning of science operation of the Fermi Large Area Telescope (LAT). We are now able to investigate the high-energy γ-ray source at the position of η Carinae over its full orbital period. By this, we can address and confirm earlier predictions for temporal and spectral variability. Methods. Newer versions of the LAT datasets, instrument response functions and background models allow for a more accurate analysis. Therefore it is important to re-evaluate the previously analyzed time period along with the new data to further constrain location, spectral shape, and flux time history of the γ-ray source. Results. We confirm earlier predictions of increasing flux values above 10 GeV toward the next periastron passage. For the most recent part of the data sample, flux values as high as those before the first periastron passage in 2008 are recorded. A comparison of spectral energy distributions around periastron and apastron passages reveals strong variation in the high-energy band. This is due to a second spectral component that is present only around periastron. Conclusions. Improved spatial consistency with the γ-ray source at the position of η Carinae along with the confirmation of temporal variability above 10 GeV in conjunction with the orbital period strengthens the argument for unambiguous source identification. Spectral variability provides additional constraints for future modeling of the particle acceleration and γ-ray emission in colliding-wind binary systems.
Aspects of Current Correlators in Holographic Theories with Hyperscaling Violation

We study the low energy and low momentum behavior of current correlators in a class of holographic zero-temperature finite density critical theories which do not respect the hyperscaling relation. The dual holographic description is assumed to be given by probe D-branes embedded in background geometries characterized by a dynamical critical exponent $z$ and a hyperscaling violation exponent $\theta$. We show that a subset of these theories with $1\leq z<2(1-\theta/d)$ exhibit a stable linearly-dispersing mode in their low energy spectrum of excitations. This mode, which appears as a pole in the retarded correlators of charge density and longitudinal currents, has some characteristics similar to that of the zero sound in Fermi liquids. Given some reasonable assumptions, we argue that the class of theories with $\theta =d-1$ that logarithmically violate the area law in the entanglement entropy in a manner reminiscent of theories with Fermi surfaces, does \emph {not} exhibit a zero sound-like mode in the low energy spectrum of the probe sector. Furthermore, utilizing the holographic Wilsonian approach, we explicitly show that such a mode has a natural interpretation as a Goldston boson arising from the spontaneous breaking of a specific symmetry.
MODELING SELF-SUBTRACTION IN ANGULAR DIFFERENTIAL IMAGING: APPLICATION TO THE HD 32297 DEBRIS DISK

We present a new technique for forward-modeling self-subtraction of spatially extended emission in observations processed with angular differential imaging (ADI) algorithms. High-contrast direct imaging of circumstellar disks is limited by quasi-static speckle noise, and ADI is commonly used to suppress those speckles. However, the application of ADI can result in self-subtraction of the disk signal due to the disk's finite spatial extent. This signal attenuation varies with radial separation and biases measurements of the disk's surface brightness, thereby compromising inferences regarding the physical processes responsible for the dust distribution. To compensate for this attenuation, we forward model the disk structure and compute the form of the self-subtraction function at each separation. As a proof of concept, we apply our method to 1.6 and 2.2 μm Keck adaptive optics NIRC2 scattered-light observations of the HD 32297 debris disk reduced using a variant of the “locally optimized combination of images” algorithm. We are able to recover disk surface brightness that was otherwise lost to self-subtraction and produce simplified models of the brightness distribution as it appears with and without self-subtraction. From the latter models, we extract radial profiles for the disk's brightness, width, midplane position, and color that are unbiased by self-subtraction. Our analysis of these measurements indicates a break in the brightness profile power law at r ≈ 110 AU and a disk width that increases with separation from the star. We also verify disk curvature that displaces the midplane by up to 30 AU toward the northwest relative to a straight fiducial midplane.
SMALL-SCALE STRUCTURE IN THE SLOAN DIGITAL SKY SURVEY AND ΛCDM: ISOLATED ∼L* GALAXIES WITH BRIGHT SATELLITES

We use a volume-limited spectroscopic sample of isolated galaxies in the Sloan Digital Sky Survey to investigate the frequency and radial distribution of luminous (Mr ≲ −18.3) satellites like the Large Magellanic Cloud (LMC) around ∼L* Milky Way (MW) analogs and compare our results object-by-object to ΛCDM predictions based on abundance matching in simulations. We show that 12% of MW-like galaxies host an LMC-like satellite within 75 kpc (projected), and 42% within 250 kpc (projected). This implies ∼10% have a satellite within the distance of the LMC, and ∼40% of L* galaxies host a bright satellite within the virialized extent of their dark matter halos. Remarkably, the simulation reproduces the observed frequency, radial dependence, velocity distribution, and luminosity function of observed secondaries exceptionally well, suggesting that ΛCDM provides an accurate reproduction of the observed universe to galaxies as faint as L ∼ 109 L☉ on ∼50 kpc scales. When stacked, the observed projected pairwise velocity dispersion of these satellites is σ ≃ 160 km s−1, in agreement with abundance-matching expectations for their host halo masses. Finally, bright satellites around L* primaries are significantly redder than typical galaxies in their luminosity range, indicating that environmental quenching is operating within galaxy-size dark matter halos that typically contain only a single bright satellite. This redness trend is in stark contrast to the MW's LMC, which is unusually blue even for a field galaxy. We suggest that the LMC's discrepant color might be further evidence that it is undergoing a triggered star formation event upon first infall.
Free motion around black holes with discs or rings: between integrability and chaos - II: Chaos around black holes with discs or rings

Geodesic dynamics is regular in the fields of isolated statio n ry black holes. However, due to the presence of unstable periodic orbits, it easily becomes chaotic under various perturbations. Here we examine what amount of stochasticity is induced in Sc hwarzschild space-time by a presence of an additional source. Following astrophysical motivation, we specifically consider thin rings or discs lying symmetrically around the hole, and describe the total field in terms of exact static and axially symmetric solutions of Einstein ’s equations. The growth of chaos in time-like geodesic motion is illustrated on Poincaré se ctions, on time series of position or velocity and their Fourier spectra, and on time evolution of the orbital “latitudinal action”. The results are discussed in dependence on the mass and position f the ring/disc and on geodesic parameters (energy and angular momentum). In the Introduct ion, we also add an overview of the literature.
Multiwavelength Light Curves of Two Remarkable Sagittarius A* Flares

Sgr A*, the supermassive black hole (SMBH) at the center of our Milky Way Galaxy, is known to be a variable source of X-ray, near-infrared (NIR), and submillimeter radiation and therefore a prime candidate to study the electromagnetic radiation generated by mass accretion flow onto a black hole and/or a related jet. Disentangling the power source and emission mechanisms of this variability is a central challenge to our understanding of accretion flows around SMBHs. Simultaneous multiwavelength observations of the flux variations and their time correlations can play an important role in obtaining a better understanding of possible emission mechanisms and their origin. This paper presents observations of two flares that both apparently violate the previously established patterns in the relative timing of submillimeter/NIR/X-ray flares from Sgr A*. One of these events provides the first evidence of coeval structure between NIR and submillimeter flux increases, while the second event is the first example of the sequence of submillimeter/X-ray/NIR flux increases all occurring within ∼1 hr. Each of these two events appears to upend assumptions that have been the basis of some analytic models of flaring in Sgr A*. However, it cannot be ruled out that these events, even though unusual, were just coincidental. These observations demonstrate that we do not fully understand the origin of the multiwavelength variability of Sgr A* and show that there is a continued and important need for long-term, coordinated, and precise multiwavelength observations of Sgr A* to characterize the full range of variability behavior.
Temperature response in nonequilibrium stochastic systems

The linear response to temperature changes is derived for systems with overdamped stochastic dynamics. Holding both in transient and steady-state conditions, the results allow to compute nonequilibrium thermal susceptibilities from unperturbed correlation functions. These correlations contain a novel form of entropy flow due to temperature unbalances, next to the standard entropy flow of stochastic energetics and to complementary time-symmetric dynamical aspects. Our derivation hinges on a time rescaling, which is a key procedure for comparing apparently incommensurable path weights. An interesting notion of thermal time emerges from this approach.
A new X-ray nova MAXI J1910-057 (=Swift J1910.2-0546) and mass accretion inflow

We report on a long-term monitoring of a newly discovered X-ray nova, MAXI J1910-057 (= Swift J1910.2-0546), by MAXI and Swift. The new X-ray transient was first detected on 2012 May 31 by MAXI Gas Slit Camera (GSC) and Swift Burst Alert Telescope (BAT) almost simultaneously. We analyzed X-ray and UV data for 270 days since the outburst onset taken by repeated MAXI scans and Swift pointing observations. The obtained X-ray light curve for the inital 90 days is roughly represented by a fast-rise and exponential-decay profile. However, it re-brightened on the ~110 days after the onset and finally went down below both GSC and BAT detec- tion limits on the 240 day. All the X-ray energy spectra are fitted well with a model consisting of a multi-color-disk blackbody and its Comptonized hard tail. During the soft-state periods, the inner-disk radius of the best-fit model were almost constant. If the radius represents the innermost stable circular orbit of a non-spinning black hole and the soft-to-hard transitions occur at 1-4% of the Eddington luminosity, the mass of the compact object is estimated to be > 2.9Mo and the distance to be > 1.70 kpc. The inner-disk radius became larger in the hard / hard-intermediate state. This suggests that the accretion disk would be truncated. We detected an excess of the UV flux over the disk blackbody component extrapolated from the X-ray data, which can be modelled as reprocessed emission irradiated by the inner disk. We also found that the UV light curve mostly traced the X-ray curve, but a short dipping event was observed in both the UV and the X-ray bands with a 3.5-day X-ray time lag. This can be interpreted as the radial inflow of accreting matter from the outer UV region to the inner X-ray region.
Applying constrained simulations for low temperature lattice QCD at finite baryon chemical potential

We study the density of states method as well as reweighting to explore the low temperature phase diagram of QCD at finite baryon chemical potential. We use four flavors of staggered quarks, a tree-level Symanzik improved gauge action and four stout smearing steps on lattices with $N_s=4,6,8$ and $N_t=6 - 16$. We compare our results to that of the phase quenched ensemble and also determine the pion and nucleon masses. In the density of states approach we applied pion condensate or gauge action density fixing. We found that the density of states method performs similarly to reweighting. At $T \approx 100$ MeV, we found an indication of the onset of the quark number density at around $\mu/m_N \sim 0.16 - 0.18$ on $6^4$ lattices at $\beta=2.9$.
Ionization of the atomic gas in redshifted radio sources

We report the results of a survey for H I 21-cm absorption at z ≲ 0.4 in a new sample of radio sources with the Giant Metrewave Radio Telescope. Of the 11 sources for which there are good data, we obtain zero detections, where four are expected upon accounting for the ionizing photon rates and sensitivity. Adding these to the previously published values, we confirm that the non-detection of 21-cm absorption in active sources at high redshift is due to photo-ionization of the gas rather than excitation by 21-cm photons (significant at 6.09σ and 2.90σ, respectively). We also confirm a strong correlation between the absorption strength and the reddening of the source, suggesting that dust plays a significant role in shielding the gas from the ambient ultraviolet field. An anticorrelation between the 21-cm detection rate and the radio turnover frequency is also found, which runs contrary to what is expected on the basis that the higher the turnover frequency, the more compact the source. It is, however, consistent with the hypothesis that the turnover frequency is related to the electron density, supported by a correlation between the turnover frequency and ionizing photon rate.
Measurements and Models of 915 MHz LoRa Radio Propagation in an Underground Gold Mine

Underground mining increasingly relies on wireless communications for its operations. The move to automating many underground mining processes makes an understanding of the propagation characteristics of key wireless technologies underground a topic of considerable importance. LoRa has great potential for communications in underground mines, but data on its propagation are quite scarce. In this paper, we describe our measurements of LoRa radio propagation in an underground gold mine. We took measurements in an extraction tunnel with line of sight and in extraction and access tunnels without line of sight. We observed excellent propagation, both with and without line of sight. Our observations support claims by others that the steel-lined tunnels act as a waveguide. As well as reporting measurements, we also developed models of propagation. For line of sight, we show that pathloss is well modelled by a power law with pathloss index of 1.25 and that variability of signal strength is well modelled by a lognormal distribution. We also successfully modelled propagation without line of sight over short distances using a Fresnel Diffraction and Free Space model.
Modeling the Effects of Drift Orbit Bifurcation on Radiation Belt Electrons

Drift orbit bifurcation (DOB) has been suggested to play a major role in the loss and transport of radiation belt electrons since it violates the second adiabatic invariants of particles and makes the third invariant undefined. Results from our guiding‐center test particle simulations using the Tsyganenko‐1989c magnetic field model show that the DOB could affect a broad region of the outer radiation belt, which can penetrate inside the geosynchronous orbit at Kp ≥ 3, and its effects are more significant further away from the Earth, at a higher Kp and for higher electron energies. Specifically, the short‐term simulation results after one electron drift show both traditional and nontraditional DOB transport of electrons, with the nontraditional DOB, caused by a third minimum of the magnetic field strength near the equator, reported here for the first time. Moreover, our results show large ballistic jumps in the second invariant and radial distance for electrons at high equatorial pitch angles after one drift. In addition, long‐term DOB transport coefficients of electrons over many drifts are calculated based on our simulation results. We find that the pitch angle and radial diffusion coefficients of electrons due to DOB could be comparable to or even larger than those caused by electron interactions with chorus and Ultra‐Low‐Frequency waves, respectively. In sum, our results demonstrate that DOB could cause effective loss and transport of radiation belt electrons even in the absence of waves.
Hadron plus photon production in polarized hadronic collisions at next-to-leading order accuracy

We compute the next-to-leading order QCD corrections to the polarized (and unpolarized) cross sections for the production of a hadron accompanied by an opposite-side prompt photon. This process, being studied at RHIC, permits us to reconstruct partonic kinematics using experimentally measurable variables. We study the correlation between the reconstructed momentum fractions and the true partonic ones, which in the polarized case might allow us to reveal the spin-dependent gluon distribution with a higher precision.
Three-dimensional Simulation of Double Detonations in the Double-degenerate Model for Type Ia Supernovae and Interaction of Ejecta with a Surviving White Dwarf Companion

We study the hydrodynamics and nucleosynthesis in the double-detonation model of Type Ia supernovae (SNe Ia) and the interaction between the ejecta and a surviving white dwarf (WD) companion in the double-degenerate scenario. We set up a binary star system with 1.0 and 0.6 M⊙ carbon–oxygen (CO) WDs, where the primary WD consists of a CO core and helium (He) shell with 0.95 and 0.05 M⊙, respectively. We follow the evolution of the binary star system from the initiation of an He detonation, ignition and propagation of a CO detonation, and the interaction of SN ejecta with the companion WD. The companion (or surviving) WD gets a flung-away velocity of ∼1700 km s−1 and captures 56Ni of ∼0.03 M⊙ and He of . Such He can be detected on the surface of surviving WDs. The SN ejecta contains a “companion-origin stream” and unburned materials stripped from the companion WD ( ), although the stream compositions would depend on the He shell mass of the companion WD. The ejecta has also a velocity shift of ∼1000 km s−1 due to the binary motion of the exploding primary WD. These features would be prominent in nebular-phase spectra of oxygen emission lines from the unburned materials like SN 2010lp and iPTF14atg and of blue- or redshifted Fe-group emission lines from the velocity shift like a part of subluminous SNe Ia. We expect that SN Ia counterparts to the D6 model would leave these fingerprints for SN Ia observations.
A PARALLAX DISTANCE AND MASS ESTIMATE FOR THE TRANSITIONAL MILLISECOND PULSAR SYSTEM J1023+0038

The recently discovered transitional millisecond pulsar system J1023+0038 exposes a crucial evolutionary phase of recycled neutron stars for multiwavelength study. The system, comprising the neutron star itself, its stellar companion, and the surrounding medium, is visible across the electromagnetic spectrum from the radio to X-ray/gamma-ray regimes and offers insight into the recycling phase of millisecond pulsar evolution. Here, we report on multiple-epoch astrometric observations with the Very Long Baseline Array (VLBA) which give a system parallax of 0.731 ± 0.022 milliarcseconds (mas) and a proper motion of 17.98 ± 0.05 mas yr−1. By combining our results with previous optical observations, we are able to use the parallax distance of 1368+42 − 39 pc to estimate the mass of the pulsar to be 1.71 ± 0.16 M☉, and we are also able to measure the three-dimensional space velocity of the system to be 126 ± 5 km s−1. Despite the precise nature of the VLBA measurements, the remaining ∼3% distance uncertainty dominates the 0.16 M☉ error on our mass estimate.
Far infrared and terahertz spectroscopy of ferroelectric soft modes in thin films: A review

ABSTRACT Far-infrared and terahertz spectroscopy of ferroelectric soft and central modes in thin films on substrates is reviewed. In addition to classical displacive proper ferroelectrics, also incipient and relaxor ferroelectrics and multiferroics are discussed. Special attention is paid to differences between the soft-mode behavior in thin films and bulk materials (ceramics and single crystals) and their influence on the low-frequency permittivity. Particularly the effects of the thin film strains and depolarizing electric fields of the probing waves on the grain boundaries are emphasized. The soft-mode spectroscopy is shown to be a very sensitive tool to reveal the thin film quality.