Miracle-dz/UniFAR-FTUs huggingface dataset:
LATE-TIME LIGHT CURVES OF TYPE II SUPERNOVAE: PHYSICAL PROPERTIES OF SUPERNOVAE AND THEIR ENVIRONMENT

We present BVRIJHK-band photometry of six core-collapse supernovae, SNe 1999bw, 2002hh, 2003gd, 2004et, 2005cs, and 2006bc, measured at late epochs (>2 yr) based on the Hubble Space Telescope (HST), and the Gemini North, and WIYN telescopes. We also show the JHK light curves of supernova impostor SN 2008S up to day 575 because it was serendipitously in our SN 2002hh field of view. Of our 43 HST observations in total, 36 observations are successful in detecting the light from the SNe alone and measuring magnitudes of all the targets. HST observations show a resolved scattered light echo around SN 2003gd at day 1520 and around SN 2002hh at day 1717. Our Gemini and WIYN observations detected SNe 2002hh and 2004et as well. Combining our data with previously published data, we show VRIJHK-band light curves and estimate decline magnitude rates at each band in four different phases. Our prior work on these light curves and other data indicate that dust is forming in our targets from days ∼300 to 400, supporting SN dust formation theory. In this paper we focus on other physical properties derived from late-time light curves. We estimate 56Ni masses for our targets (0.5–14 × 10−2 M☉) from the bolometric light curve of each of days ∼150–300 using SN 1987A as a standard (7.5 × 10−2 M☉). The flattening or sometimes increasing fluxes in the late-time light curves of SNe 2002hh, 2003gd, 2004et, and 2006bc indicate the presence of light echoes. We estimate the circumstellar hydrogen density of the material causing the light echo and find that SN 2002hh is surrounded by relatively dense materials (n(H) >400 cm−3) and SNe 2003gd and 2004et have densities more typical of the interstellar medium (∼1 cm−3). We analyze the sample as a whole in the context of physical properties derived in prior work. The 56Ni mass appears well correlated with progenitor mass with a slope of 0.31 × 10−2, supporting the previous work by Maeda et al., who focus on more massive Type II SNe. The dust mass does not appear to be correlated with progenitor mass.
The nature and energetics of AGN-driven perturbations in the hot gas in the Perseus Cluster

In this paper, cores of relaxed galaxy clusters are often disturbed by AGN. Their Chandra observations revealed a wealth of structures induced by shocks, subsonic gas motions, bubbles of relativistic plasma, etc. In this paper, we determine the nature and energy content of gas fluctuations in the Perseus core by probing statistical properties of emissivity fluctuations imprinted in the soft- and hard-band X-ray images. About 80 per cent of the total variance of perturbations on ~8–70 kpc scales in the core have an isobaric nature, i.e. are consistent with subsonic displacements of the gas in pressure equilibrium with the ambient medium. The observed variance translates to the ratio of energy in perturbations to thermal energy of ~13 per cent. In the region dominated by weak ‘ripples’, about half of the total variance is associated with isobaric perturbations on scales of a few tens of kpc. If these isobaric perturbations are induced by buoyantly rising bubbles, then these results suggest that most of the AGN-injected energy should first go into bubbles rather than into shocks. Using simulations of a shock propagating through the Perseus atmosphere, we found that models reproducing the observed features of a central shock have more than 50more » per cent of the AGN-injected energy associated with the bubble enthalpy and only about 20 per cent is carried away with the shock. Such energy partition is consistent with the AGN-feedback model, mediated by bubbles of relativistic plasma, and supports the importance of turbulence in the cooling–heating balance. « less
Model of Liver Fibrosis Induction by Thioacetamide in Rats for Regenerative Therapy Studies

Hepatic fibrosis is caused by chronic injury due to toxic, infectious, or metabolic causes, and it may progress to cirrhosis and hepatocellular carcinoma. There is currently no antifibrotic therapy authorized for human use; however, there are promising studies using cell therapies. There are also no animal models that exactly reproduce human liver fibrosis that can be used to better understand the mechanisms of its regression and identify new targets for treatment and therapeutic approaches. On the other hand, mesenchymal stem cells (MSC) have experimentally demonstrated fibrosis regression effects, but it is necessary to have an animal model of advanced liver fibrosis to evaluate the effect of these cells. The aim of this work was to establish a protocol for the induction of advanced liver fibrosis in rats using thioacetamide (TAA), which will allow us to perform trials using MSC as a possible therapy for fibrosis regression. For this purpose, we selected 24 female rats and grouped them into three experimental groups: the control group (G-I) without treatment and groups II (G-II) and III (G-III) that received TAA by intraperitoneal injection for 24 weeks. Then, 1 × 106/kg adipose mesenchymal stem cells (ASCs) were infused intravenously. Groups G-I and G-II were sacrificed 7 days after the last dose of ASC, and G-III was sacrificed 8 weeks after the last ASC infusion, all with xylazine/ketamine (40 mg/kg). The protocol used in this work established a model of advanced hepatic fibrosis as corroborated by METAVIR tests of the histological lesions; by the high levels of the markers α-SMA, CD68, and collagen type I; by functional alterations due to elevated markers of the hepatic lesions; and by alterations of the leukocytes, lymphocytes, and platelets. Finally, transplanted cells in the fibrous liver were detected. We conclude that TAA applied using the protocol introduced in this study induces a good model of advanced liver fibrosis in rats.
Small Bites: star formation recipes in extreme dwarfs

We study the relationship between the gas column density (∑ HI ) and the star formation rate surface density (∑ SSFR ) for a sample of extremely small (M B ~−13, ΔV 50 ~ 30 km s −1 ) dwarf irregular galaxies. We find a clear stochasticity in the relation between the gas column density and star formation. All gas with ∑ HI ≳ 10 M ⊙ pc −2 has some ongoing star formation, but the fraction of the gas with ongoing star formation decreases as the gas column density decreases and falls to about 50 per cent at ∑ HI ~ 3 M ⊙ pc −2 . Further, even for the most dense gas, the star formation efficiency is at least a factor of ~ 2 smaller than typical of star-forming regions in spirals. We also find that the ratio of H emission to far-ultraviolet emission increases with the increasing gas column density. This is unlikely to be due to increasing dust extinction because the required dust-to-gas ratios are too high. We suggest instead that this correlation arises because massive (i.e. Hα-producing) stars are formed preferentially in regions with high gas density.
Geometrical complexity of the antidots unit cell effect on the spin wave excitations spectra

Three types of antidot lattices (ADLs) based on a permalloy thin film, with increasing complexity of the unit cell: simple square, bi-component square, and wave-like ADLs were studied experimentally using both ferromagnetic resonance and Brillouin light scattering spectroscopy techniques. An additional small antidot placed in the center of the square unit cell induces significant modification of the ADL spin-wave spectrum and changes its dependence on the orientation of the in-plane applied magnetic field. The introduction of air-gaps connecting small and large antidots transforms the system into the wave-like ADL and results in further changes in the spin-wave spectrum, including a strong discrimination between two mutually orthogonal principal directions of the ADL in terms of spin-wave propagation. We also point out the impact of defected holes on the obtained spectra. The micromagnetic simulations and the calculation based on the plane wave method satisfactorily confirmed the experimental results.
On the universality of interstellar filaments: theory meets simulations and observations

Filaments are ubiquitous in the universe. Recent observations have revealed that stars and star clusters form preferentially along dense filaments. Understanding the formation and properties of filaments is therefore a crucial step in understanding star formation. Here we perform three-dimensional high-resolution magnetohydrodynamical simulations that follow the evolution of molecular clouds and the formation of filaments and stars. We apply a filament detection algorithm and compare simulations with different combinations of physical ingredients: gravity, turbulence, magnetic fields and jet/outflow feedback. We find that gravity-only simulations produce significantly narrower filament profiles than observed, while simulations that include turbulence produce realistic filament properties. For these turbulence simulations, we find a remarkably universal filament width of 0.10 +/- 0.02 pc, which is independent of the star formation history of the clouds. We derive a theoretical model that provides a physical explanation for this characteristic filament width, based on the sonic scale (lambda_sonic) of molecular cloud turbulence. Our derivation provides lambda_sonic as a function of the cloud diameter L, the velocity dispersion sigma_v, the gas sound speed c_s, and the ratio of thermal to magnetic pressure, plasma beta. For typical cloud conditions in the Milky Way spiral arms, we find lambda_sonic = 0.04-0.16 pc, in excellent agreement with the filament width of 0.05-0.15 pc from observations. Consistent with the theoretical model assumptions, we find that the velocity dispersion inside the filaments is subsonic and supersonic outside. We further explain the observed p=2 scaling of the filament density profile, rho ~ r^(-p) with the collision of two planar shocks forming a filament at their intersection.
Common envelope events with low-mass giants: understanding the transition to the slow spiral-in

We present a three-dimensional (3D) study of common envelope events (CEEs) to provide a foundation for future one-dimensional (1D) methods to model the self-regulated phase of a CEE. The considered CEEs with a low-mass red giant end with one of three different outcomes -- merger, slow spiral-in, or prompt formation of a binary. To understand which physical processes determine different outcomes, and to evaluate how well 1D simulations model the self-regulated phase of a CEE, we introduce tools that map our 3D models to 1D profiles. We discuss the differences in the angular momentum and energy redistribution in 1D and 3D codes. We identified four types of ejection processes: the pre-plunge-in ejection, the outflow during the plunge-in, the outflow driven by recombination, and the ejection triggered by a contraction of the circumbinary envelope. Significant mass is lost in all cases, including the mergers. Therefore a self-regulated spiral-in can start only with a strongly reduced envelope mass. We derive the condition to start a recombination outflow, which can proceed either as a runaway or a stationary outflow. We show that the way the energy of the inspiraling companion is added to the envelope in 1D studies intensifies the envelope's entropy increase, alters the start of the recombination outflow, and leads to different outcomes in 1D and 3D studies. The steady recombination outflow may dispel most of the envelope in all slow spiral-in cases, making the existence of a long-term self-regulated phase debatable, at least for low-mass giant donors.
A LINK BETWEEN STAR FORMATION QUENCHING AND INNER STELLAR MASS DENSITY IN SLOAN DIGITAL SKY SURVEY CENTRAL GALAXIES

We study the correlation between galaxy structure and the quenching of star formation using a sample of Sloan Digital Sky Survey central galaxies with stellar masses 9.75 < log M*/M☉ < 11.25 and redshifts z < 0.075. Galaxy Evolution Explorer UV data are used to cleanly divide the sample into star-forming and quenched galaxies and to identify galaxies in transition (the green valley). Despite a stark difference in visual appearance between blue and red galaxies, their average radial stellar mass density profiles are remarkably similar (especially in the outer regions) at fixed mass. The inner stellar mass surface density within a radius of 1 kpc, Σ1, is used to quantify the growth of the bulge as galaxies evolve. When galaxies are divided into narrow mass bins, their distribution in the color-Σ1 plane at fixed mass forms plausible evolutionary tracks. Σ1 seems to grow as galaxies evolve through the blue cloud, and once it crosses a threshold value, galaxies are seen to quench at fixed Σ1. The Σ1 threshold for quenching grows with stellar mass, . However, the existence of some star-forming galaxies above the threshold Σ1 implies that a dense bulge is necessary but not sufficient to quench a galaxy fully. This would be consistent with a two-step quenching process in which gas within a galaxy is removed or stabilized against star formation by bulge-driven processes (such as a starburst, active galactic nucleus feedback, or morphological quenching), whereas external gas accretion is suppressed by separate halo-driven processes (such as halo gas shock heating). Quenching thus depends on an interplay between the inner structure of a galaxy and its surrounding dark matter halo, and lack of perfect synchrony between the two could produce the observed scatter in color versus Σ1.
Triple excitations in perturbed relativistic coupled-cluster theory and electric dipole polarizability of group-IIB elements

We use perturbed relativistic coupled-cluster (PRCC) theory to compute the electric dipole polarizabilities $\alpha$ of Zn, Cd and Hg. The computations are done using the Dirac-Coulomb-Breit Hamiltonian with Uehling potential to incorporate vacuum polarization corrections. The triple excitations are included perturbatively in the PRCC theory, and in the unperturbed sector, it is included non-perturbatively. Our results of $\alpha$, for all the three elements, are in excellent agreement with the experimental data. The other highlight of the results is the orbital energy corrections from Breit interactions. In the literature we could only get the data of Hg {E. Lindroth et al., J. Phys. B 22, 2447 (1989)} and are near perfect match with our results. We also present the linearized equations of the cluster amplitudes, including the triple excitations, with the angular factors.
Maximum population transfer in a periodically driven quantum system

We study the dynamics of a two-level quantum system under the influence of sinusoidal driving in the intermediate frequency regime. Analyzing the Floquet quasienergy spectrum, we find combinations of the field parameters for which population transfer is optimal and takes place through a series of well defined steps of fixed duration. We also show how the corresponding evolution operator can be approximated at all times by a very simple analytical expression. We propose this model as being specially suitable for treating periodic driving at avoided crossings found in complex multi-level systems, and thus show a relevant application of our results to designing a control protocol in a realistic molecular model
Majorana edge modes with gain and loss

We consider a non-Hermitian generalization of the Kitaev model and study the existence of stable Majorana zero energy modes. We show that they exist in the limit of zero chemical potential even if balanced gain and loss are randomly distributed along the lattice. We show that Majorana zero modes also appear if the chemical potential is different from zero provided that not the full Hamiltonian but the non-Hermitian part of the Hamiltonian is $\mathcal{PT}$ symmetric.
Nice triples and the Grothendieck–Serre conjecture concerning principal G-bundles over reductive group schemes

In a series of papers [Pan0], [Pan1], [Pan2], [Pan3] we give a detailed and better structured proof of the Grothendieck--Serre's conjecture for semi-local regular rings containing a finite field. The outline of the proof is the same as in [P1],[P2],[P3]. If the semi-local regular ring contains an infinite field, then the conjecture is proved in [FP]. Thus the conjecture is true for regular local rings containing a field. The present paper is the one [Pan1] in that new series. Theorem 1.1 is one of the main result of the paper. It is also one of the key steps in the proof of the Grothendieck--Serre's conjecture for semi-local regular rings containing a field (see [Pan3]). The proof of Theorem 1.1 is completely geometric.
Homogenization of high order elliptic operators with periodic coefficients

In $L_2({\mathbb R}^d;{\mathbb C}^n)$, we study a selfadjoint strongly elliptic operator $A_\varepsilon$ of order $2p$ given by the expression $b({\mathbf D})^* g({\mathbf x}/\varepsilon) b({\mathbf D})$, $\varepsilon >0$. Here $g({\mathbf x})$ is a bounded and positive definite $(m\times m)$-matrix-valued function in ${\mathbb R}^d$; it is assumed that $g({\mathbf x})$ is periodic with respect to some lattice. Next, $b({\mathbf D})=\sum_{|\alpha|=p}^d b_\alpha {\mathbf D}^\alpha$ is a differential operator of order $p$ with constant coefficients; $b_\alpha$ are constant $(m\times n)$-matrices. It is assumed that $m\ge n$ and that the symbol $b({\boldsymbol \xi})$ has maximal rank. For the resolvent $(A_\varepsilon - \zeta I)^{-1}$ with $\zeta \in {\mathbb C} \setminus [0,\infty)$, we obtain approximations in the norm of operators in $L_2({\mathbb R}^d;{\mathbb C}^n)$ and in the norm of operators acting from $L_2({\mathbb R}^d;{\mathbb C}^n)$ to the Sobolev space $H^p({\mathbb R}^d;{\mathbb C}^n)$, with error estimates depending on $\varepsilon$ and $\zeta$.
The StEllar Counterparts of COmpact high velocity clouds (SECCO) survey - II. Sensitivity of the survey and the atlas of synthetic dwarf galaxies

The searching for StEllar Counterparts of COmpact high velocity clouds (SECCO) survey is devoted to the search for stellar counterparts within ultra compact high velocity clouds that are candidate low-mass, low-luminosity galaxies. We present the results of a set of simulations aimed at the quantitative estimate of the sensitivity of the survey as a function of the total luminosity, size, and distance of the stellar systems we are looking for. For all of our synthetic galaxies we assumed an exponential surface brightness profile and an old and metal-poor population. The synthetic galaxies are simulated both on the images and on the photometric catalogues, taking all the observational effects into account. In the fields where the available observational material is of top quality (≃36% of the SECCO fields), we detect synthetic galaxies as ≥5 σ over-densities of resolved stars down to μ V, h ≃ 30.0 mag/arcsec 2 , for D ≤ 1.5 Mpc, and down to μ V, h ≃ 29.5 mag/arcsec 2 , for D ≤ 2.5 Mpc. In the field with the worst observational material of the whole survey, we detect synthetic galaxies with μ V, h ≤ 28.8 mag/arcsec 2 out to D ≤ 1.0 Mpc, and those with μ V, h ≤ 27.5 mag/arcsec 2 out to D ≤ 2.5 Mpc. Dwarf galaxies with M V = −10.0, with sizes in the range spanned by known dwarfs, are detected by visual inspection of the images up to D = 5 Mpc independent of the image quality. In the best quality images, dwarfs are partially resolved into stars up to D = 3.0 Mpc and completely unresolved at D = 5 Mpc. As an independent test of the sensitivity of our images to low surface brightness galaxies, we report on the detection of several dwarf spheroidal galaxies probably located in the Virgo cluster with M V ≲ −8.0 and μ V, h ≲ 26.8 mag/arcsec 2 . The nature of the previously discovered SECCO 1 stellar system, also likely located in the Virgo cluster, is rediscussed in comparison with these dwarfs. While specific for the SECCO survey, our study may also provide general guidelines for the detection of faint stellar systems with 8 m class telescopes.
HOW DEAD ARE DEAD GALAXIES? MID-INFRARED FLUXES OF QUIESCENT GALAXIES AT REDSHIFT 0.3 < z < 2.5: IMPLICATIONS FOR STAR FORMATION RATES AND DUST HEATING

We investigate star formation rates (SFRs) of quiescent galaxies at high redshift (0.3 < z < 2.5) using 3D-HST WFC3 grism spectroscopy and Spitzer mid-infrared data. We select quiescent galaxies on the basis of the widely used UVJ color–color criteria. Spectral energy distribution (SED) fitting (rest-frame optical and near-IR) indicates very low SFRs for quiescent galaxies (sSFR ∼ 10−12 yr−1). However, SED fitting can miss star formation if it is hidden behind high dust obscuration and ionizing radiation is re-emitted in the mid-infrared. It is therefore fundamental to measure the dust-obscured SFRs with a mid-IR indicator. We stack the MIPS 24 μm images of quiescent objects in five redshift bins centered on z = 0.5, 0.9, 1.2, 1.7, 2.2 and perform aperture photometry. Including direct 24 μm detections, we find sSFR ∼ 10−11.9 × (1 + z)4 yr−1. These values are higher than those indicated by SED fitting, but at each redshift they are 20–40 times lower than those of typical star-forming galaxies. The true SFRs of quiescent galaxies might be even lower, as we show that the mid-IR fluxes can be due to processes unrelated to ongoing star formation, such as cirrus dust heated by old stellar populations and circumstellar dust. Our measurements show that star formation quenching is very efficient at every redshift. The measured SFR values are at z > 1.5 marginally consistent with the ones expected from gas recycling (assuming that mass loss from evolved stars refuels star formation) and well below that at lower redshifts.
Ordered spectral statistics in one-dimensional disordered supersymmetric quantum mechanics and Sinai diffusion with dilute absorbers

Some results on the ordered statistics of eigenvalues for one-dimensional random Schrödinger Hamiltonians are reviewed. In the case of supersymmetric quantum mechanics with disorder, the existence of low-energy delocalized states induces eigenvalue correlations and makes the ordered statistics problem non-trivial. The resulting distributions are used to analyze the problem of classical diffusion in a random force field (Sinai problem) in the presence of weakly concentrated absorbers. It is shown that the slowly decaying averaged return probability of the Sinai problem, , is converted into a power-law decay, , where g is the strength of the random force field and ρ the density of absorbers.