Miracle-dz/UniFAR-FTUs huggingface dataset:
On the thermal sensitivity of binary formation in collapsing molecular clouds

We report the results of a numerical study on the initial formation stages of low-mass protostellar binary systems. We determine the separation of protostellar binaries formed as a function of the initial thermal state by varying the initial temperature in a slightly modified version of the Burkert and Bodenheimer collapse test. We find that the outcome is highly sensitive to both the initial temperature of the cloud and the initial amplitude of azimuthal density perturbation A. For A=10 %, variations of only 1 unit Kelvin below 10 K lead to changes of up to 100 AU ( i.e. of order 30 %) in the instantaneous separation, whereas for this small A the initial temperatures above 10 K yield, instead of a binary, a single low-mass fragment that never reaches protostellar densities. Protostellar binaries, however, do emerge when the perturbation amplitude is increased from 10 % to 25 %. We also investigate the impact of the critical density which governs the transition from isothermal to adiabatic thermodynamic behaviour of the collapsing gas. We find that the critical density not only affects the overall structural evolution of the gas envelope, but also the size of the rotating disk structures formed during collapse as well as the number of protostellar fragments resulting from the final fragmentation of the disks. This mechanism can give rise to young protostellar objects constituting bound multiple stellar systems.
On the interaction between tides and convection

We study the interaction between tides and convection in astrophysical bodies by analysing the effect of a homogeneous oscillatory shear on a fluid flow. This model can be taken to represent the interaction between a large-scale periodic tidal deformation and a smaller scale convective motion. We first consider analytically the limit in which the shear is of low amplitude and the oscillation period is short compared to the time-scales of the unperturbed flow. In this limit there is a viscoelastic response and we obtain expressions for the effective elastic modulus and viscosity coefficient. The effective viscosity is inversely proportional to the square of the oscillation frequency, with a coefficient that can be positive, negative or zero depending on the properties of the unperturbed flow. We also carry out direct numerical simulations of Boussinesq convection in an oscillatory shearing box and measure the time-dependent Reynolds stress. The results indicate that the effective viscosity of turbulent convection falls rapidly as the oscillation frequency is increased, attaining small negative values in the cases we have examined, although significant uncertainties remain because of the turbulent noise. We discuss the implications of this analysis for astrophysical tides.
Trans-Planckian issues for inflationary cosmology

The accelerated expansion of space during the cosmological inflation period leads to trans-Planckian issues which need to be addressed. Most importantly, the physical wavelength of fluctuations which are studied at the present time by means of cosmological observations may well originate with a wavelength smaller than the Planck length at the beginning of the inflationary phase. Thus, questions arise as to whether the usual predictions of inflationary cosmology are robust considering our ignorance of physics on trans-Planckian scales, and whether the imprints of Planck-scale physics are at the present time observable. These and other related questions are reviewed in this paper.
Molecular clouds under the influence of massive stars in the Galactic Hii region G353.2+0.9

Aims. We investigate the structure of the Galactic Hii region G353.2+0.9, by analyzing (sub-)mm molecular-line and -continuum observations. This region is excited by the massive open cluster Pismis-24. We study the detailed morphology, distribution, and physical parameters (column and volume densities, masses, temperatures and opacities) of the molecular gas and dust. We are also interested in the variation in these parameters across the photon-dominated region. Methods. We observed various molecules and transitions to derive the physical properties of the molecular gas through line ratios, and both LTE and non-LTE analyses. The physical properties of the gas were derived with a Bayesian approach for the non-LTE analysis. Based on the continuum data at 870 μm, we derived the column density of molecular hydrogen from the surface brightness and thus molecular abundances from the molecular column densities. We determined the mass of the dust from the integrated flux. We also carried out the simplest possible analysis to identify the clump candidates for gravitational instability, determining their virial parameter α. Results. The total mass of the gas in the region is ∼2000 M� , while that of the dust is ∼21 M� . The presence of a velocity gradient in the region, with clumps with redder VLSR nearer Pis-24 suggests that the expansion of the ionized gas is pushing the molecular gas away from the observer. We unambiguously identify the ionization front in G353.2+0.9, at the location of which we detect an increase in gas density and temperature. Its location and position angle is consistent with Pis-24 being the main ionization source. Almost no molecular gas is found south of the ionization front, at the location of the intense, elongated continuum and atomic-line emission, strengthening the hypothesis that Pis-24 is associated with G353.2+0.9. We find at least 14 clumps at different positions and LSR velocities, and we determine their physical conditions. The typical excitation temperatures are in the range of about 10−25 K, while H2 column densities are in the range ∼10 20 −10 23 cm −2 . From the non-LTE analysis, we derive kinetic temperatures in the ranges 11−45 K (CS) and 20−45 K (CN). The H2 number density is typically around ∼10 5 cm −3 from CS and few × 10 5 cm −3 from CN, with maxima above 10 6 cm −3 . The abundances of the molecules observed are found to vary across the region, and appear to be higher
Theoretical modelling of emission-line galaxies: new classification parameters for mid-infrared and optical spectroscopy

We have carried out extensive and detailed photoionization modeling to successfully constrain the locations of different emission-line galaxies in optical and mid-infrared diagnostic diagrams. Our model grids cover a wide range in parameter space for the active galaxy continuum and starburst galaxies with different stellar population laws and metallicities. We compare the predicted AGN and star-formation mid-infrared line ratios [Ne III]15.56mm/[Ne II]12.81mm and [O IV]25.89mm/[Ne III]15.56mm to the observed values, and find that the best fit for the AGN is via a two-zone approximation. This two-zone approximation is a combination of a matter-bounded component, where [Ne III] and [O IV] are emitted efficiently, and a radiation-bounded component that maximizes [Ne II] emission. We overlay the predictions from this two-zone approximation onto the optical [O III]l5007/Hbeta and [N II]l6583/Halpha diagnostic diagram derived from the Sloan Digital Sky Survey, to find that the high-density and low-ionization radiation-bounded component in our two-zone AGN approximation model provides a good lower limit for [N II] emission. This establishes a new theoretical demarcation line for the minimum AGN contribution in this diagram. This new classification results by a factor of ~1.4 in a higher AGN population than predictions derived from previous divisions of star-forming galaxies. Similarly, we define a maximum AGN contribution in the [O III]/Hbeta and [N II]/Halpha diagram by using a two-zone approximation within a parameter range typical of the narrow-line region.
A flexible method to evolve collisional systems and their tidal debris in external potentials

We introduce a numerical method to integrate tidal effects on collisional systems, using any definition of the external potential as a function of space and time. Rather than using a linearisation of the tidal field, this new method follows a differential technique to numerically evaluate the tidal acceleration and its time derivative. Theses are then used to integrate the motions of the components of the collisional systems, like stars in star clusters, using a predictor-corrector scheme. The versatility of this approach allows the study of star clusters, including their tidal tails, in complex, multi-components, time-evolving external potentials. The method is implemented in the code nbody6 (Aarseth 2003).
Interplay between omega-nucleon interaction and nucleon mass in dense baryonic matter

The dilaton-limit fixed point and the scaling properties of hadrons in the close vicinity of the fixed point in dense baryonic matter uncovered in hidden local symmetry implemented with spontaneously broken scale symmetry are shown to reveal a surprisingly intricate interplay, hitherto unsuspected, between the origin of the bulk of proton mass and the renormalization-group flow of the \omega-nuclear interactions. This rends a theoretical support to the previous (phenomenologically) observed correlation between the dropping nucleon mass and the behavior of the \omega-nuclear interactions in dense matter described in terms of half skyrmions that appear at a density denoted $n_{1/2}$ in skyrmion crystals. The role of the \omega-meson degree of freedom in the source for nucleon mass observed in this paper is highly reminiscent of its important role in the skyrmion description of nucleon mass in hidden local symmetric theory. One of the most notable novel results found in this paper is that the nucleon mass in dense baryonic medium undergoes a drop roughly linear in density up to a density (denoted $\tilde{n}$) slightly above nuclear matter density ($n_0$) and then stays more or less constant up to the dilaton limit fixed point. The possibility that we entertain is that $\tilde{n}$ coincides with or at least close to $n_{1/2}$. We note that this feature can be economically captured by the parity-doublet model for nucleons with the chiral-invariant mass $m_0\sim (0.7-0.8) m_N$. It is found in one-loop renormalization-group analysis with the Lagrangian adopted that while the \rho-NN coupling "runs" in density, the \omega-NN coupling does not scale: it will scale at two-loop or higher-loop order, but at a slower pace, so it is more appropriate to say it "walks" rather than runs.
High efficiency, hybrid electrochromic device on polycarbonate substrates with neon sputtered WO3-x thin films

Electrochromic materials change color reversibly by applying an external DC voltage. One among the many emerging application of electro-chromics is the smart windows. The coloration efficiency, the optical colour modulation and the cyclability are the factors that bench mark the device. Tungsten oxide (WO3-x) is versatile material and reactive DC magnetron sputtering (with argon as sputter gas) technique is common for electro-chromics. In the present communication we have prepared tungsten oxide thin films by reactive DC magnetron sputtering technique (at room temperature 300 K) using Neon as the sputter gas. The thickness of the WO3 thin films are varied from 190 nm to 712 nm. These WO3 thin films are subjected for electrochemical measurements with three electrode electrochemical cell in presence of 1M HCl, 1M Li2SO4 aqueous electrolyte and we have prepared a solid state electrochromic device with nafion thin film. The highest coloration efficiency of the neon sputtered WO3 is observed as 187.9 cm2/C by lithium intercalation.
A Galaxy Redshift Survey Near HST/COS AGN Sight Lines

To establish the connection between galaxies and UV-detected absorption systems in the local universe, a deep (g ≤ 20) and wide (∼20′ radius) galaxy redshift survey is presented around 47 sight lines to UV-bright AGNs observed by the Cosmic Origins Spectrograph (COS). Specific COS science team papers have used this survey to connect absorbers to galaxies, groups of galaxies, and large-scale structures, including voids. Here we present the technical details of the survey and the basic measurements required for its use, including redshifts for individual galaxies and uncertainties determined collectively by spectral class (emission-line, absorption-line, and composite spectra) and completeness for each sight line as a function of impact parameter and magnitude. For most of these sight lines, the design criteria of >90% completeness over a >1 Mpc region down to ≲0.1 L* luminosities at z ≤ 0.1 allows a plausible association between low-z absorbers and individual galaxies. Lyα covering fractions are computed to approximate the star-forming and passive galaxy populations using the spectral classes above. In agreement with previous results, the covering fraction of star-forming galaxies with L ≥ 0.3 L* is consistent with unity inside one virial radius and declines slowly to >50% at four virial radii. On the other hand, passive galaxies have lower covering fractions (∼60%) and a shallower decline with impact parameter, suggesting that their gaseous halos are patchy but have a larger scale-length than star-forming galaxies. All spectra obtained by this project are made available electronically for individual measurement and use.
UV INSIGHTS INTO THE COMPLEX POPULATIONS OF M87 GLOBULAR CLUSTERS

We have imaged with Hubble Space Telescope WFC3/UVIS the central 2 &farcm; 7 × 2 &farcm; 7 ? > region of the giant elliptical galaxy M87, using the ultraviolet filter F275W. In combination with archival ACS/WFC data taken through the F606W and F814W filters, covering the same field, we have constructed integrated-light UV–optical colors and magnitudes for 1460 objects, most of which are believed to be globular clusters (GCs) belonging to M87. The purpose was to ascertain whether the multiple-populations syndrome, ubiquitous among Galactic GCs, also exists among the M87 family of clusters. To achieve this goal, we sought those GCs with exceptionally blue UV-to-optical colors because helium-enriched sub-populations produce a horizontal-branch morphology that is well populated at high effective temperature. For comparison, integrated, synthetic UV–optical and purely optical colors and magnitudes have been constructed for 45 Galactic GCs, starting from individual-star photometry obtained with the same instruments and the same filters. We identify a small group of M87 clusters exhibiting a radial UV–optical color gradient, representing our best candidate GCs hosting multiple populations with extreme helium content. We also find that the central spatial distribution of the bluer GCs is flattened in a direction parallel to the jet, while the distribution of redder GCs is more spherical. We release to the astronomical community our photometric catalog in F275W, F606W, and F814W bands and the high-quality image stacks in the same bands.
Higher-order-in-spin interaction Hamiltonians for binary black holes from Poincaré invariance

The fulfillment of the space-asymptotic Poincare algebra is used to derive new higher-order-in-spin interaction Hamiltonians for binary black holes in the Arnowitt-Deser-Misner canonical formalism almost completing the set of the formally 1/c{sup 4} spin-interaction Hamiltonians involving nonlinear spin terms. To linear order in G, the expressions for the S{sup 3}p and the S{sup 2}p{sup 2} Hamiltonians are completed. It is also shown that there are no quartic nonlinear S{sup 4} Hamiltonians to linear order in G.
Genetic Characterization of the Poultry Red Mite (Dermanyssus gallinae) in Poland and a Comparison with European and Asian Isolates

(1) Background: The blood-feeding mite Dermanyssus gallinae (De Geer 1778) continues to attract wide interest from researchers and bird breeders. The aim of this study was to evaluate the genetic diversity of D. gallinae populations in five commercial laying hen farms in Poland and to determine their similarity with isolates from other countries. The study involved an analysis of a fragment of the cytochrome c oxidase subunit I gene (COI). A total of 38 isolates obtained from Polish farms and 338 sequences deposited in GenBank were analyzed. (2) Results: Haplotype No. 46 was dominant (90%) in Polish isolates and was homologous with the isolates from Great Britain, the Netherlands, Belgium, Japan, and South Korea. These results are indicative of high genetic homogeneity and common ancestry of the poultry red mite and point to a common source of infestation in the examined farms. (3) Conclusions: The genetic diversity of D. gallinae should be further studied to promote a better understanding of how this parasite is disseminated within and between countries.
Increase of magnetic hyperthermia efficiency due to dipolar interactions in low-anisotropy magnetic nanoparticles: Theoretical and experimental results

When magnetic nanoparticles (MNPs) are single-domain and magnetically independent, their magnetic properties and the conditions to optimize their efficiency in magnetic hyperthermia applications are now well-understood. However, the influence of magnetic interactions on magnetic hyperthermia properties is still unclear. Here, we report hyperthermia and high-frequency hysteresis loop measurements on a model system consisting of MNPs with the same size but a varying anisotropy, which is an interesting way to tune the relative strength of magnetic interactions. A clear correlation between the MNP anisotropy and the squareness of their hysteresis loop in colloidal solution is observed : the larger the anisotropy, the smaller the squareness. Since low anisotropy MNPs display a squareness higher than the one of magnetically independent nanoparticles, magnetic interactions enhance their heating power in this case. Hysteresis loop calculations of independent and coupled MNPs are compared to experimental results. It is shown that the observed features are a natural consequence of the formation of chains and columns of MNPs during hyperthermia experiments: in these structures, when the MNP magnetocristalline anisotropy is small enough to be dominated by magnetic interactions, the hysteresis loop shape tends to be rectangular, which enhance their efficiency. On the contrary, when MNPs do not form chains and columns, magnetic interactions reduces the hysteresis loop squareness and the efficiency of MNPs compared to independent ones. The present work should improve the understanding and interpretation of magnetic hyperthermia experiments.
Magnification Bias of Distant Galaxies in the Hubble Frontier Fields: Testing Wave Versus Particle Dark Matter Predictions

Acting as powerful gravitational lenses, the strong lensing galaxy clusters of the deep Hubble Frontier Fields (HFF) program permit access to lower-luminosity galaxies lying at higher redshifts than hitherto possible. We analyzed the HFF to measure the volume density of Lyman-break galaxies at z > 4.75 by identifying a complete and reliable sample up to z ≃ 10. A marked deficit of such galaxies was uncovered in the highly magnified regions of the clusters relative to their outskirts, implying that the magnification of the sky area dominates over additional faint galaxies magnified above the flux limit. This negative magnification bias is consistent with a slow rollover at the faint end of the UV luminosity function and it indicates a preference for Bose–Einstein condensate dark matter with a light boson mass of m B ≃ 10 − 22 eV over standard cold dark matter. We emphasize that measuring the magnification bias requires no correction for multiply-lensed images (with typically three or more images per source), whereas directly reconstructing the luminosity function will lead to an overestimate unless such images can be exhaustively matched up, especially at the faint end that is only accessible in the strongly lensed regions. In addition, we detected a distinctive downward transition in galaxy number density at z ≳ 8, which may be linked to the relatively late reionization reported by Planck. Our results suggests that JWST will likely peer into an “abyss” with essentially no galaxies detected in deep NIR imaging at z > 10.
Detection of H i in distant galaxies using spectral stacking

Using the Parkes radio telescope, we study the 21cm neutral hydrogen (H i) properties of a sample of galaxies with redshifts z < 0.13 extracted from the optical 2dF Galaxy Redshift Survey (2dFGRS). Galaxies at 0.04 < z < 0.13 are studied using new Parkes observations of a 42deg 2 field near the South Galactic Pole (SGP). A spectral stacking analysis of the 3,277 2dFGRS objects within this field results in a convincing 12σ detection. For the low-redshift sample at 0 < z < 0.04, we use the 15,093 2dFGRS galaxies observed by the H i Parkes All-Sky Survey (HIPASS) and find a 31σ stacked detection. We measure average H i masses of (6.93± 0.17)× 10 9 h −2 M⊙ and (1.48 ± 0.03) × 10 9 h −2 M⊙ for the SGP and HIPASS samples, respectively. Accounting for source confusion and sample bias, we find a cosmic H i mass density of H i = (3.19 +0.43 −0.59 ) × 10 −4 h −1 for the SGP sample and (2.82 +0.30 −0.59 ) × 10 −4 h −1 for the HIPASS sample. This suggests no (12±23%) evolution in the cosmic H i density over the last �1h −1 Gyr. Due to the very large effective volumes, cosmic variance in our determination of H i is considerably lower than previous estimates. Our stacking analysis reproduces and quantifies the expected trends in the H i mass and mass-to-light ratio of galaxies with redshift, luminosity and colour.
The X-ray luminous cluster underlying the bright radio-quiet quasar H1821+643

We present a Chandra observation of the only low redshift, z = 0.299, galaxy cluster to contain a highly luminous radio-quiet quasar, H1821+643. By simulating the quasar point spread function, we subtract the quasar contribution from the cluster core and determine the physical properties of the cluster gas down to 3 arcsec (15 kpc) from the point source. The temperature of the cluster gas decreases from 9.0 ± 0.5 down to 1.3 ± 0.2 keV in the centre, with a short central radiative cooling time of 1.0 ± 0.1 Gyr, typical of a strong cool-core cluster. The X-ray morphology in the central 100 kpc shows extended spurs of emission from the core, a small radio cavity and a weak shock or cold front forming a semicircular edge at ~15 arcsec radius. The quasar bolometric luminosity was estimated to be ~2 x 10 47 erg s -1 , requiring a mass accretion rate of ~40 M ⊙ yr -1 , which corresponds to half the Eddington accretion rate. We explore possible accretion mechanisms for this object and determine that Bondi accretion, when boosted by Compton cooling of the accretion material, could provide a significant source of the fuel for this outburst. We consider H1821+643 in the context of a unified active galactic nucleus (AGN) accretion model and, by comparing H1821+643 with a sample of galaxy clusters, we show that the quasar has not significantly affected the large-scale cluster gas properties.
The cosmological constant and the black hole equation of state

The thermodynamics of black holes in various dimensions are described in the presence of a negative cosmological constant which is treated as a thermodynamic variable, interpreted as a pressure in the equation of state. The black hole mass is then identified with the enthalpy, rather than the internal energy, and heat capacities are calculated at constant pressure not at constant volume. The Euclidean action is associated with a bridge equation for the Gibbs free energy and not the Helmholtz free energy. Quantum corrections to the enthalpy and the equation of state of the BTZ black hole are studied.