Miracle-dz/UniFAR-FTUs huggingface dataset:
Super-Eddington accretion; flow regimes and conditions in high-z galaxies

We review and discuss theoretical studies addressing the possibility of gas accretion onto black holes occurring at rates exceeding the Eddington limit. Our focus is on the applications to the growth of black hole seeds at high redshift. We first present the general notion of Super-Eddington accretion, and then summarize the different models and numerical simulations developed to study such regime. We consider optically thick flows in accretion disks as well as in spherically symmetric envelopes, and devote particular attention to the widely adopted model based on the SLIM disk solution. While attractive for its simplicity, the SLIM disk solution is challenged by the latest generation of three-dimensional radiation (magneto)-hydrodynamical simulations, in which radiative losses can be an order of magnitude higher, and the mechanisms of radiation transport is more complex than straight advection as it takes place in a complex turbulent regime. We then discuss the gas supply rate to the sub-pc scale accretion disk or envelope from larger scales, revisiting gas inflow rates in protogalaxies under various conditions. We conclude that in the dense gaseous nuclei of high-z galaxies the conditions necessary for the onset of Super Eddington accretion regimes, such as a high optical depth and high gas supply rates from large scales, should be naturally met. Feedback from the growing BH seed should not alter significantly such conditions according to the results of radiation magneto-hydrodynamical simulations of super-critical flows in accretion disks. Furthermore, based on the required nuclear gas inflow rates and the tendency of stellar feedback to remove efficiently gas in low mass halos, we argue that super-critical accretion will be more easily achieved in relatively sizable halos, with virial masses $M_{\rm vir} > 10^{10}$ M$_{\odot}$, which become more common at $z < 15$.
The Imperial IRAS-FSC Redshift Catalogue: luminosity functions, evolution and galaxy bias

We present the luminosity function and selection function of 60 μm galaxies selected from the Imperial IRAS-FSC Redshift Catalogue. Three methods, including the 1/V max and the parametric and non-parametric maximum-likelihood estimators, are used and the results agree well with each other. A density evolution α (1 + z) 3.4±0.9 or a luminosity evolution α exp( 1.7 t L /τ), where t L is the look-back time, is detected in the full sample in the redshift range [0.02, 0.1], consistent with previous analyses. Of the four infrared subpopulations, cirrus-type galaxies and M82-type starbursts show similar evolutionary trends, galaxies with significant active galactic nucleus contributions show stronger positive evolution and Arp 220-type starbursts exhibit strong negative evolution. The dominant subpopulation changes from cirrus-type galaxies to M82-type starbursts at log 10 (L 60 /L ⊙ ) ≈ 10.3. In the second half of the paper, we derive the projected two-point spatial correlation function for galaxies of different infrared template types. The mean relative bias between cirrus-type galaxies and M82-type starbursts, which correspond to quiescent galaxies with optically thin interstellar dust and actively star-forming galaxies, respectively, is calculated to be b cirrus /b M82 = 1.25 ± 0.07. The relation between the current star formation rate (SFR) in star-forming galaxies and environment is investigated by looking at the dependence of clustering on infrared luminosity. We found that M82-type actively star-forming galaxies show stronger clustering as infrared luminosity/SFR increases. The correlation between the clustering strength and SFR in the local Universe seems to echo the basic trend seen in star-forming galaxies in the Great Observatories Origins Deep Survey fields (at z ∼ 1).
Submillimeter absorption from SH+, a new widespread interstellar radical, 13CH+ and HCl

We have used the Atacama Pathfinder Experiment 12 m telescope (APEX) to carry out an absorption study of submillimeter wavelength rotational ground-state lines of H 35 Cl, H 37 Cl, 13 CH + , and, for the first time, of the SH + radical (sulfoniumylidene or sulfanylium). We detected the quartet of ground-state hyperfine structure lines of SH + near 683 GHz with the CHAMP+ array receiver against the strong continuum source Sagittarius B2, which is located close to the center of our Galaxy. In addition to absorption from various kinematic components of Galactic center gas, we also see absorption at the radial velocities belonging to intervening spiral arms. This demonstrates that SH + is a ubiquitous component of the diffuse interstellar medium. We do not find clear evidence for other SH + lines we searched for, which is partially due to blending with lines from other molecules. In addition to SH + , we observed absorption from H 35 Cl, H 37 Cl, and 13 CH + . The observed submillimeter absorption is compared in detail with absorption in 3 mm transitions of H 13 CO + and c-C3H2 and the CO J = 1− 0a nd 3−2 transitions.
Thick discs, and an outflow, of dense gas in the nuclei of nearby Seyfert galaxies

We discuss the dense molecular gas in central regions of nearby Seyfert galaxies, and report new arcsec resolution observations of HCN(1-0) and HCO$^+$(1-0) for 3 objects. In NGC 3079 the lines show complex profiles as a result of self-absorption and saturated continuum absorption. H$^{13}$CN reveals the continuum absorption profile, with a peak close to the galaxy's systemic velocity that traces disk rotation, and a second feature with a blue wing extending to $-350$km s$^{-1}$ that most likely traces a nuclear outflow. The morphological and spectral properties of the emission lines allow us to constrain the dense gas dynamics. We combine our kinematic analysis for these 3 objects, as well as another with archival data, with a previous comparable analysis of 4 other objects, to create a sample of 8 Seyferts. In 7 of these, the emission line kinematics imply thick disk structures on radial scales of $\sim$100pc, suggesting such structures are a common occurrence. We find a relation between the circumnuclear LHCN and Mdyn that can be explained by a gas fraction of 10% and a conversion factor {\alpha}HCN $\sim$ 10 between gas mass and HCN luminosity. Finally, adopting a different perspective to probe the physical properties of the gas around AGN, we report on an analysis of molecular line ratios which indicates that the clouds in this region are not self-gravitating.
A FAR-ULTRAVIOLET ATLAS OF LOW-RESOLUTION HUBBLE SPACE TELESCOPE SPECTRA OF T TAURI STARS

We present a far-ultraviolet (FUV) spectral atlas consisting of spectra of 91 pre-main-sequence stars. Most stars in this sample were observed with the Space Telescope Imaging Spectrograph and Advanced Camera for Surveys on the Hubble Space Telescope (HST). A few archival spectra from the International Ultraviolet Explorer and the Goddard High Resolution Spectrograph on HST are included for completeness. We find strong correlations among the O i λ1304 triplet, the Si iv λλ1394/1403 doublet, the C iv λ1549 doublet, and the He ii λ1640 line luminosities. For classical T Tauri stars (CTTSs), we also find strong correlations between these lines and the accretion luminosity, suggesting that these lines form in processes related to accretion. These FUV line fluxes and X-ray luminosity correlate loosely with large scatters. The FUV emission also correlates well with Hα, Hβ, and Ca ii K line luminosities. These correlations between FUV and optical diagnostics can be used to obtain rough estimates of FUV line fluxes from optical observations. Molecular hydrogen (H2) emission is generally present in the spectra of actively accreting CTTSs but not the weak-lined T Tauri stars that are not accreting. The presence of H2 emission in the spectrum of HD 98800 N suggests that the disk should be classified as actively accreting rather than a debris disk. We discuss the importance of FUV radiation, including the hydrogen Lyα line, on the photoevaporation of exoplanet atmospheres. We find that the Ca ii/C iv flux ratios for more evolved stars are lower than those for less evolved accretors, indicating preferential depletion of refractory metals into dust grains.
Statistically convex-cocompact actions of groups with contracting elements

This paper presents a study of the asymptotic geometry of groups with contracting elements, with emphasis on a subclass of statistically convex-cocompact (SCC) actions. The class of SCC actions includes relatively hyperbolic groups, CAT(0) groups with rank-1 elements and mapping class groups, among others. We exploit an extension lemma to prove that a group with SCC actions contains large free sub-semigroups, has purely exponential growth and contains a class of barrier-free sets with a growth-tight property. Our study produces new results and recovers existing ones for many interesting groups through a unified and elementary approach.
Decay constants and form factors of s-wave and p-wave mesons in the covariant light-front quark model

We reanalyze the decay constants of s-wave and p-wave mesons and the D, B ? M form factors, where M represents a pseudoscalar meson, a vector meson, a scalar meson or an axial vector meson within a covariant light-front quark model. The parameter ? for wavefunctions of most of s-wave mesons and that of a few axial-vector mesons are fixed with the latest experimental information, wherever available or using the lattice calculations. The treatment of masses and mixing angles for strange axial vector mesons is improved for the purpose. We extend our analysis to determine the form factors appearing in the Ds, Bs ? M transitions, and to the isoscalar final state mesons. Numerical results of the form factors for transitions between a heavy pseudoscalar meson and an s-wave or a p-wave light meson and their momentum dependence are presented in detail. Further, their sensitivity to uncertainties of the ? parameters of the initial as well as the final mesons is investigated. Some experimental measurements of the charmed and bottom meson decays are employed to compare the decay constants and transition form factors obtained in this and other works.
Pulsar current revisited

The pulsar current, in the P– u P plane where P is the pulsar period and u P is the period derivative, is used as a supposedly “model free” way to estimate the pulsar birthrate from statistical data on pulsars. We reconsider the derivation of the kinetic equation on which this is based, and argue that the interpretation of the pulsar current is strongly model dependent, being sensitive to the form of the assumed evolution law for pulsars. We discuss the case where the trajectory of a pulsar is assumed to be of the form u P = KP 2 n with K and n constant, and show that (except for n = 2) one needs to introduce a pseudo source term in order to infer the birthrate from the pulsar current. We illustrate the effect of this pseudo source term using pulsar data to estimate the birthrate for different choices of n. We define and discuss an alternative “potential” class of evolution laws for which this complication is avoided due to the pseudo source term being identically zero.
Predicting politicians’ misconduct: Evidence from Colombia

Abstract Corruption has pervasive effects on economic development and the well-being of the population. Despite being crucial and necessary, fighting corruption is not an easy task because it is a difficult phenomenon to measure and detect. However, recent advances in the field of artificial intelligence may help in this quest. In this article, we propose the use of machine-learning models to predict municipality-level corruption in a developing country. Using data from disciplinary prosecutions conducted by an anti-corruption agency in Colombia, we trained four canonical models (Random Forests, Gradient Boosting Machine, Lasso, and Neural Networks), and ensemble their predictions, to predict whether or not a mayor will commit acts of corruption. Our models achieve acceptable levels of performance, based on metrics such as the precision and the area under the receiver-operating characteristic curve, demonstrating that these tools are useful in predicting where misbehavior is most likely to occur. Moreover, our feature-importance analysis shows us which groups of variables are most important in predicting corruption.
A comparative study of experiments with numerical simulations of free-stream turbulence transition

Abstract To date, very few careful and direct comparisons between experiments and direct numerical simulations (DNS) have been published on free-stream turbulence (FST) induced boundary layer transition, whilst there exist numerous published works on the comparison of canonical turbulent boundary layers. The primary reason is that the former comparison is vastly more difficult to carry out simply because all known transition scenarios have large energy gradients and are extremely sensitive to surrounding conditions. This paper presents a detailed comparison between new experiments and available DNS data of the complex FST transition scenario in a flat plate boundary layer at turbulence intensity level about $Tu = 3\,\%$ and FST Reynolds number about $Re_{{fst}} = 67$. The leading edge (LE) pressure gradient distribution and the full energy spectrum at the LE are identified as the two most important parameters for a satisfying comparison. Matching the LE characteristic FST parameters is not enough as previously thought, which is illustrated by setting up two experimental FST cases with about the same FST integral parameters at the LE but with different energy spectra. Finally, an FST boundary layer penetration depth (PD) measure is defined using DNS, which suggests that the PD grows with the downstream distance and stays around 20 % of the boundary layer thickness down to transition onset. With this result, one cannot rule out the significance of the continuous FST forcing along the boundary layer edge in this transition scenario, as indicated in previous studies.
Is decision-making impairment an endophenotype of anorexia nervosa?

Abstract Background Patients with anorexia nervosa (AN) show impaired decision-making ability, but it is still unclear if this is a trait marker (i.e., being associated with AN at any stage of the disease) or a state parameter of the disease (i.e., being present only in acutely ill patients), and if it has endophenotypic characteristics. The aim of this study was to determine the endophenotypic, and state- or trait-associated nature of decision-making impairment in AN. Methods Ninety-one patients with acute AN (A-AN), 90 unaffected relatives (UR), 23 patients remitted from AN (R-AN), and 204 healthy controls (HC) carried out the Iowa gambling task (IGT). Prospective valence learning (PVL) model was employed to distinguish the cognitive dimensions underlying the decision-making process, that is, learning, consistency, feedback sensitivity, and loss aversion. IGT performance and decision-making dimensions were compared among groups to assess whether they had endophenotypic (i.e., being present in A-AN, UR, and R-AN, but not in HC) and/or trait-associated features (i.e., present in A-AN and R-AN but not in HC). Results Patients with A-AN had lower performance at the IGT (p < 0.01), while UR, R-AN, and HC had comparable results. PVL-feedback sensitivity was lower in patients with R-AN and A-AN than in HC (p < 0.01). Conclusions Alteration of decision-making ability did not show endophenotypic features. Impaired decision-making seems a state-associated characteristic of AN, resulting from the interplay between trait-associated low feedback sensitivity and state-associated features of the disease.
Approaches To Quantum Gravity

One of the main challenges in theoretical physics over the last five decades has been to reconcile quantum mechanics with general relativity into a theory of quantum gravity. However, such a theory has been proved to be hard to attain due to i) conceptual difficulties present in both the component theories (General Relativity (GR) and Quantum Theory); ii) lack of experimental evidence, since the regimes at which quantum gravity is expected to be applicable are far beyond the range of conceivable experiments. Despite these difficulties, various approaches for a theory of Quantum Gravity have been developed. In this thesis we focus on two such approaches: Loop Quantum Gravity and the Topos theoretic approach. The choice fell on these approaches because, although they both reject the Copenhagen interpretation of quantum theory, their underpinning philosophical approach to formulating a quantum theory of gravity are radically different. In particular LQG is a rather conservative scheme, inheriting all the formalism of both GR and Quantum Theory, as it tries to bring to its logical extreme consequences the possibility of combining the two. On the other hand, the Topos approach involves the idea that a radical change of perspective is needed in order to solve the problem of quantum gravity, especially in regard to the fundamental concepts of `space' and `time'. Given the partial successes of both approaches, the hope is that it might be possible to find a common ground in which each approach can enrich the other.
Carbon Impurities on Graphene Synthesized by Chemical Vapor Deposition on Platinum

We report nanocrystalline carbon impurities coexisting with graphene synthesized via chemical vapor deposition (CVD) on platinum. We observe micron-size island-like impurity layers, which can easily be mistaken for second graphene layers in optical microscopy or secondary electron microscopy (SEM). The island orientation depends on the crystalline orientation of the Pt, as shown by electron backscatter diffraction(EBSD), indicating growth of amorphous carbon below graphene. Dark-field TEM indicates that in addition to uniform single-crystal graphene, our sample is decorated with nanocrystalline carbon impurities with a spatially inhomogeneous distribution. Raman spectra show a large D peak, however electrical characterization shows high mobility (~6,000 cm2/Vs), indicating a limitation for Raman spectroscopy in characterizing the electronic quality of graphene.
On the metallicity of open clusters - I. Photometry

Context. Metallicity is one of four free parameters typically considered when fitting isochrones to the cluster sequence. Unfortunately, this parameter is often ignored or assumed to be solar in most papers. Hence an unknown bias is introduced in the estimation of the other three cluster parameters (age, reddening and distance). Furthermore, studying the metallicity of open clusters allows us not only to derive the Galactic abundance gradient on a global scale, but also to trace the local solar environment in more detail. Aims. In a series of three papers, we investigate the current status of published metallicities for open clusters from widely different photometric and spectroscopic methods. A detailed comparison of the results allows us to establish more reliable photometric calibrations and corrections for isochrone fitting techniques. Well established databases such as WEBDA help us to perform a homogeneous analysis of available measurements for a significant number of open clusters. Methods. The literature was searched for [Fe/H] estimates on the basis of photometric calibrations in any available filter system. On the basis of results published by Tadross, we demonstrate the caveats of the calibration choice and its possible impact. In total, we find 406 individual metallicity values for 188 open clusters within 64 publications. The values were, finally, unweightedly averaged. Results. Our final sample includes [Fe/H] values for 188 open clusters. Tracing the solar environment within 4000 x 4000 pc(2) we identify a patchy metallicity distribution as an extension to the Local Bubble that significantly influences the estimation of the Galactic metallicity gradient, even on a global scale. In addition, further investigations of more distant open clusters are clearly needed to obtain a more profound picture at Galactocentric distances beyond 10 000 pc. Conclusions. Only a combination of all available photometric and spectroscopic data will shed more light on how the local and global Galactic properties are correlated with metallicity.
The dynamics of Andromeda's dwarf galaxies and stellar streams

Abstract As part of the Z-PAndAS Keck II DEIMOS survey of resolved stars in our neighboring galaxy, Andromeda (M31), we have built up a unique data set of measured velocities and chemistries for thousands of stars in the Andromeda stellar halo, particularly probing its rich and complex substructure. In this contribution, we will discuss the structural, dynamical and chemical properties of Andromeda's dwarf spheroidal galaxies, and how there is no observational evidence for a difference in the evolutionary histories of those found on and off M31's vast plane of satellites. We will also discuss a possible extension to the most significant merger event in M31 - the Giant Southern Stream - and how we can use this feature to refine our understanding of M31's mass profile, and its complex evolution.
DAMA and CoGeNT without astrophysical uncertainties

The CoGeNT collaboration has reported evidence of an annual modulation in its first fifteen months of data. Here we compare the amplitude and phase of this signal to the modulation observed by the DAMA collaboration, assuming that both arise due to elastically scattering dark matter (DM). We directly map the CoGeNT signal to the DAMA detector without specifying any astrophysical parameters and compare this with the signal measured by DAMA. We also compare with constraints from CDMS II and XENON10. We find that DM of mass 5-14 GeV that couples equally to protons and neutrons is strongly disfavoured. Isospin-violating DM fares better but requires a boosted modulation fraction.
Self-consistent microscopic description of neutron scattering by 16 O based on the continuum particle-vibration coupling method

The microscopic description of neutron scattering by $^{16}$O below 30 MeV is carried out by means of the continuum particle-vibration coupling (cPVC) method with the Skyrme nucleon-nucleon ($NN$) effective interaction. In the cPVC method, a proper boundary condition on a nucleon in continuum states is imposed, which enables one to evaluate the transition matrix in a straightforward manner. Experimental data of the total and total-elastic cross sections are reproduced quite well by the cPVC method. An important feature of the result is the fragmentation of the single-particle resonance into many peaks as well as the shift of its centroid energy. Thus, some part of the fine structure of the experimental cross sections at lower energies is well described by the cPVC framework. The cPVC method based on a real $NN$ effective interaction is found to successfully explain about 85% of the reaction cross section, through explicit channel-coupling effects.