Miracle-dz/UniFAR-FTUs huggingface dataset:
PECULIAR TRANSVERSE VELOCITIES OF GALAXIES FROM QUASAR MICROLENSING. TENTATIVE ESTIMATE OF THE PECULIAR VELOCITY DISPERSION AT Z ∼ 0.5

We propose to use the flux variability of lensed quasar images induced by gravitational microlensing to measure the transverse peculiar velocity of lens galaxies over a wide range of redshift. Microlensing variability is caused by the motions of the observer, the lens galaxy (including the motion of the stars within the galaxy), and the source. Hence, its frequency is directly related to the galaxy’s transverse peculiar velocity. The idea is to count time-event rates (e.g., peak or caustic crossing rates) in the observed microlensing light curves of lensed quasars that can be compared with model predictions for different values of the transverse peculiar velocity. To compensate for the large timescale of microlensing variability, we propose to count and model the number of events in an ensemble of gravitational lenses. We develop the methodology to achieve this goal and apply it to an ensemble of 17 lensed quasar systems. In spite of the shortcomings of the available data, we have obtained tentative estimates of the peculiar velocity dispersion of lens galaxies at z ∼ 0.5, . Scaling at zero redshift, we derive , consistent with peculiar motions of nearby galaxies and with recent N-body nonlinear reconstructions of the Local Universe based on ΛCDM. We analyze the different sources of uncertainty of the method and find that for the present ensemble of 17 lensed systems the error is dominated by Poisson noise, but that for larger ensembles the impact of the uncertainty on the average stellar mass may be significant.
Spectroscopy of new brown dwarf members of ρ Ophiuchi and an updated initial mass function

Aims. To investigate the universality hypothesis of the initial mass function in the substellar regime, the population of the ρ Ophiuchi molecular cloud is analysed by including a new sample of low-mass spectroscopically confirmed members. To that end, we have conducted a large spectroscopic follow-up of young substellar candidates uncovered in our previous photometric survey. Methods. The spectral types and extinction were derived for a newly found population of substellar objects, and its masses estimated by comparison to evolutionary models. A thoroughly literature search was conducted to provide an up-to-date census of the cluster, which was then used to derive the luminosity and mass functions, as well as the ratio of brown dwarfs to stars in the cluster. These results were then compared to other young clusters. Results. It is shown that the study of the substellar population of the ρ Ophiuchi molecular cloud is hampered only by the high extinction in the cluster ruling out an apparent paucity of brown dwarfs. The discovery of 16 new members of ρ Ophiuchi, 13 of them in the substellar regime, reveals the low-mass end of its population and shows the success of our photometric candidate selection with the WIRCam survey. The study of the brown dwarf population of the cluster reveals a high disk fraction of 76 +5 −8 %. Conclusions. Taking the characteristic peak mass of the derived mass function and the ratio of brown dwarfs to stars into account, we conclude that the mass function of ρ Ophiuchi is similar to other nearby young clusters.
Kinematics and chemical properties of the Galactic stellar populations - The HARPS FGK dwarfs sample

(Abridged) We analyze chemical and kinematical properties of about 850 FGK solar neighborhood long-lived dwarfs observed with the HARPS high-resolution spectrograph. The stars in the sample have logg > 4 dex, 5000 < Teff < 6500 K, and -1.39 < [Fe/H] < 0.55 dex. We apply a purely chemical analysis approach based on the [alpha/Fe] vs. [Fe/H] plot to separate Galactic stellar populations into the thin disk, thick disk and high-alpha metal-rich (hamr). Our analysis shows a negative gradient of the rotational velocity of the thin disk stars with [Fe/H] (-17 km s^-1 dex^-1), and a steep positive gradient for both the thick disk and hamr stars with the same magnitude of about +42 km s^-1 dex^-1. For the thin disk stars we observed no correlation between orbital eccentricities and metallicity, but observed a steep negative gradient for the thick disk and hamr stars with practically the same magnitude (about -0.18 dex^-1). Our results suggest that radial migration played an important role in the formation and evolution of the thin disk. For the thick disk stars it is not possible to reach a firm conclusion about their origin. Based on the eccentricity distribution of the thick disk stars only their accretion origin can be ruled out, and the heating and migration scenario could explain the positive steep gradient of V_phi with [Fe/H]. Analyzing the hamr stellar population we found that they share properties of both the thin and thick disk population. A comparison of the properties of the hamr stars with that of the subsample of stars from the N-body/SPH simulation using radial migration suggest that they may have originated from the inner Galaxy. Further detailed investigations would help to clarify their exact nature and origin.
Improved Predictions of Reactor Antineutrino Spectra

Precise predictions of the antineutrino spectra emitted by nuclear reactors is a key ingredient in measurements of reactor neutrino oscillations as well as in recent applications to the surveillance of power plants in the context of nonproliferation of nuclear weapons. We report new calculations including the latest information from nuclear databases and a detailed error budget. The first part of this work is the so-called ab initio approach where the total antineutrino spectrum is built from the sum of all {beta} branches of all fission products predicted by an evolution code. Systematic effects and missing information in nuclear databases lead to final relative uncertainties in the 10-20% range. A prediction of the antineutrino spectrum associated with the fission of {sup 238}U is given based on this ab initio method. For the dominant isotopes we developed a more accurate approach combining information from nuclear databases and reference electron spectra associated with the fission of {sup 235}U, {sup 239}Pu, and {sup 241}Pu, measured at Institut Laue-Langevin (ILL) in the 1980s. We show how the anchor point of the measured total {beta} spectra can be used to suppress the uncertainty in nuclear databases while taking advantage of all the information they contain. Wemore » provide new reference antineutrino spectra for {sup 235}U, {sup 239}Pu, and {sup 241}Pu isotopes in the 2-8 MeV range. While the shapes of the spectra and their uncertainties are comparable to those of the previous analysis of the ILL data, the normalization is shifted by about +3% on average. In the perspective of the reanalysis of past experiments and direct use of these results by upcoming oscillation experiments, we discuss the various sources of errors and their correlations as well as the corrections induced by off-equilibrium effects. « less
Vortex structures in the wake of a marine propeller operating close to a free surface

Abstract The present paper analyses the vortical structures in the wake of a naval propeller operating underneath a free surface using detached-eddy simulation. We investigate the flow topology for several loading conditions and compare it with analogous observations behind a propeller operating in open water. We show that the wake topology is similar to that observed in open water only for low-loading conditions. For mild blade loading, the free surface's presence seems to stabilize the flow. On the contrary, for high blade loading, the mutual interaction between the vortex system and the free surface leads to vortex breakdown that overshadows the multiple pairing mechanisms observed in open-water conditions.
Transitional hypersonic flow over slender cone/flare geometries

Abstract Experiments are performed in a Mach-6 shock tunnel to examine the laminar-to-turbulent transition process associated with a sudden increase in surface angle on a slender body. A cone/flare geometry with a 5$^\circ$ frustum and compression angles ranging from 5$^\circ$ to 15$^\circ$ allow a range of mean flow configurations, spanning an attached shock-wave/boundary-layer interaction to a fully separated one; the unit Reynolds number of the flow is also varied to modify the state of incoming second-mode boundary-layer disturbances. Ultra-high-speed schlieren visualizations provide a global picture of the flow development, supplemented by high-frequency surface pressure measurements. For the 5$^\circ$ compression, the unsteady flow field is dominated by the second-mode waves, whose breakdown to turbulence is generally accelerated (compared with the straight-cone configuration) by encountering the angle change. As the compression angle is increased to induce separation, lower-frequency disturbances appear along the separated shear layer that exhibit much larger amplification rates than the incoming second-mode waves; the latter effectively freeze in amplitude downstream of the separation point before rapidly breaking down upon reattachment. The shear-layer disturbances become dominant at the largest compression angle tested. Radiation of disturbance energy to the external flow is consistently observed: this generally occurs along mean flow features (flare, separation or reattachment shocks) for the second-mode disturbances and spontaneously for the shear-layer waves. The combined application of spectral proper orthogonal decomposition and a global bispectral analysis allows the identification of important unsteady flow structures and the association of these with prominent nonlinear interactions in the various configurations.
Star formation and dust heating in the FIR bright sources of M83

We investigate star formation and dust heating in the compact far-infrared (FIR) bright sources detected in the Herschel maps of M83. We use the source extraction code getsources to detect and extract sources in the FIR, as well as their photometry in the mid-infrared and H alpha. By performing infrared spectral energy distribution fitting and applying an H alpha-based star formation rate (SFR) calibration, we derive the dust masses and temperatures, SFRs, gas masses and star formation efficiencies (SFEs). The detected sources lie exclusively on the spiral arms and represent giant molecular associations, with gas masses and sizes of 10(6)-10(8) M-circle dot and 200-300 pc, respectively. The inferred parameters show little to no radial dependence and there is only a weak correlation between the SFRs and gas masses, which suggests that more massive clouds are less efficient at forming stars. Dust heating is mainly due to local star formation. However, although the sources are not optically thick, the total intrinsic young stellar population luminosity can almost completely account for the dust luminosity. This suggests that other radiation sources also contribute to the dust heating and approximately compensate for the unabsorbed fraction of UV light.
Topotype-Based Chromosomal Diversity among Five Species of Freshwater Armored Catfishes in the Hypostomus auroguttatus Supergroup (Actinopterygii: Siluriformes)

Freshwater catfishes from the genus Hypostomus have been models for several cytogenetic studies, due to their intense variability in diploid number, chromosome morphology, and the distribution of repetitive DNAs. Taking into consideration the taxonomic complexity inherent to this group, the present study aims to describe the karyotypes of five species of Hypostomus collected in their type localities: Hypostomus albopunctatus (Regan, 1908), Hypostomus hermanni (Ihering, 1905), Hypostomus iheringii (Regan, 1908), and Hypostomus paulinus (Ihering, 1905) from the Piracicaba River (the Upper Paraná River Basin); and Hypostomus mutucae Knaack, 1999 from the Claro River (the Upper Paraguay River Basin). Our results evidenced a great inter-specific diploid-number variation: 2n = 72 (H. hermanni); 2n = 74 (H. albopunctatus); 2n = 76 (H. paulinus); 2n = 80 (H. iheringii); and 2n = 82 (H. mutucae), which reflects the important role of Robertsonian rearrangements in the karyotypic differentiation among these species. The distribution of heterochromatin also varied considerably among species, making it possible to distinguish each analyzed species, as well as to detect microstructural variations among populations of the same species. These data can support taxonomic revisions when further associated with molecular markers and morphological analyses to delimit, more consistently, the taxonomic status of these Hypostomus species, which have a complex taxonomic diagnosis history.
Structure Formation in Modified Gravity Scenarios

We study the growth of structures in modified gravity models where the Poisson equation and the relationship between the two Newtonian potentials are modified by explicit functions of space and time. This parameterisation applies to the $f(R)$ models and more generally to screened modified gravity models. We investigate the linear and weakly nonlinear regimes using the "standard" perturbative approach and a resummation technique, while we use the spherical dynamics to go beyond low-order results. This allows us to estimate the matter density power spectrum and bispectrum from linear to highly nonlinear scales, the full probability distribution of the density contrast on weakly nonlinear scales, and the halo mass function. We analyse the impact of modifications of gravity on these quantities for a few realistic models. In particular, we find that the standard one-loop perturbative approach is not sufficiently accurate to probe these effects on the power spectrum and it is necessary to use resummation methods even on weakly nonlinear scales which provide the best observational window for modified gravity as relative deviations from General Relativity do not grow significantly on smaller scales where theoretical predictions become increasingly difficult.
THE EDDINGTON LIMIT IN COSMIC RAYS: AN EXPLANATION FOR THE OBSERVED LACK OF LOW-MASS RADIO-LOUD QUASARS AND THE M•–M⋆ RELATION

We present a feedback mechanism for supermassive black holes and their host bulges that operates during epochs of radio-loud quasar activity. In the radio cores of relativistic quasar jets, internal shocks convert a fraction of ordered bulk kinetic energy into randomized relativistic ions, or in other words cosmic rays. By employing a phenomenologically motivated jet model, we show that enough 1–100 GeV cosmic rays escape the radio core into the host galaxy to break the Eddington limit in cosmic rays. As a result, hydrostatic balance is lost and a cosmic ray momentum-driven wind develops, expelling gas from the host galaxy and thus self-limiting the black hole and bulge growth. Although the interstellar cosmic ray power is much smaller than the quasar photon luminosity, cosmic rays provide a stronger feedback than UV photons, since they exchange momentum with the galactic gas much more efficiently. The amount of energy released into the host galaxy as cosmic rays, per unit of black hole rest mass energy, is independent of black hole mass. It follows that radio-loud jets should be more prevalent in relatively massive systems since they sit in galaxies with relatively deep gravitational potentials. Therefore, jet-powered cosmic ray feedback not only self-regulates the black hole and bulge growth, but also provides an explanation for the lack of radio-loud activity in relatively small galaxies. By employing basic known facts regarding the physical conditions in radio cores, we approximately reproduce both the slope and the normalization of the M•–M⋆ relation.
Gas expulsion by quasar-driven winds as a solution to the overcooling problem in galaxy groups and clusters

Galaxy groups are not scaled down versions of massive galaxy clusters - the hot gas in groups (known as the intragroup medium, IGrM for short) is, on average, less dense than the intracluster medium, implying that one or more non-gravitational processes (e.g., radiative cooling, star formation, and/or feedback) has had a relatively larger effect on groups. In the present study, we compare a number of cosmological hydrodynamic simulations that form part of the OverWhelmingly Large Simulations project to isolate and quantify the effects of cooling and feedback from supernovae (SNe) and active galactic nuclei (AGN) on the gas. This is achieved by comparing Lagrangian thermal histories of the gas in the different runs, which were all started from identical initial conditions. While radiative cooling, star formation, and SN feedback are all necessary ingredients, only runs that also include AGN feedback are able to successfully reproduce the optical and X-ray properties of groups and low-mass clusters. We isolate how, when, and exactly what gas is heated by AGN. Interestingly, we find that the gas that constitutes the present-day IGrM is that which was not strongly heated by AGN. Instead, the low median density/high median entropy of the gas in present-day groups is achieved by the ejection of lower entropy gas from low-mass progenitor galaxies at high redshift (primarily 2 . z . 4). This corresponds to the epoch when supermassive black holes accreted most of their mass, typically at a rate that is close to the Eddington limit (i.e., when the black holes are in a ‘quasar mode’).
X-ray properties of BzK-selected galaxies in the deepest X-ray fields

We investigate the X-ray properties of BzK-selected galaxies at z $\sim$ 2 using deep X-ray data in the Chandra Deep Field South and North (CDFS and CDFN). Of these we directly detect in X-rays 49 sBzKs in CDFS and 32 sBzKs in CDFN. Stacking the undetected sources also reveals a significant X-ray signal. Investigating the X-ray detection rate and stacked flux versus the IR excess parameter (i.e. SFRtotal/SFRUV,corr), we find no strong evidence for an increased X-ray detection rate, or a harder X-ray spectrum in IR Excess sBzKs. This is particularly the case when one accounts for the strong correlation between the IR excess parameter and the bolometric IR luminosity (LIR), e.g. when controlling for LIR, the IR Non-Excess sBzKs show a detection rate at least as high. While both direct detections and stacking suggest that the AGN fraction in sBzK galaxies is high, there is no clear evidence for widespread Compton thick activity in either the sBzK population generally, or the IR Excess sBzK subsample. The very hard X-ray signal obtained for the latter in earlier work was most likely contaminated by a few hard X-ray sources now directly detected in deeper X-ray data. The X-ray detection fraction of passive BzK galaxies in our sample is if anything higher than that of sBZKs, so there is no evidence for coeval black hole growth and star formation from X-ray analysis of the BzK populations. Because increased AGN activity in the IR excess population is not indicated by our X-ray analysis, it appears that the bulk of the IR Excess sBzK population are luminous star-forming galaxies whose SFRs are either overestimated at 24 microns, underestimated in the UV, or both. This conclusion reinforces recent results from Herschel which show similar effects.
MICROLENSING OF QUASAR ULTRAVIOLET IRON EMISSION

We measure the differential microlensing of the UV Fe ii and Fe iii emission line blends between 14 quasar image pairs in 13 gravitational lenses. We find that the UV iron emission is strongly microlensed in four cases with amplitudes comparable to that of the continuum. Statistically modeling the magnifications, we infer a typical size of light-days for the Fe line-emitting regions, which is comparable to the size of the region generating the UV continuum (∼3–7 light-days). This may indicate that a significant part of the UV Fe ii and Fe iii emission originates in the quasar accretion disk.
ELECTROFACIES DEFINITION AND ZONATION OF THE LOWER CRETACEOUS BARRA VELHA FORMATION CARBONATE RESERVOIR IN THE PRE‐SALT SEQUENCE OF THE SANTOS BASIN, SE BRAZIL

Lower Cretaceous carbonates in the pre‐salt succession in the Santos Basin, eastern Brazil, are highly heterogeneous in terms of their reservoir characteristics as a result of depositional and diagenetic factors. Electrofacies have widely been used for reservoir zonation and, when allied with computer‐based methods such as neural networks, may help with the study of such complex reservoir rocks and with the identification of high‐quality reservoir zones. In this work, an unsupervised artificial neural network known as a self‐organizing map (SOM) was used to carry out a zonation of the pre‐salt carbonates in the Aptian Barra Velha Formation, the main reservoir unit in the Santos Basin. Available data included gramma‐ray, neutron porosity, resistivity deep, sonic, density, photoelectric factor, total porosity and effective porosity profiles from 21 wells together with mineralogical models. Core descriptions and thin section images were used as additional data for the lithological characterization of the electrofacies and consequently for reservoir zonation. A total of four electrofacies were defined from the SOM application, and five reservoir zones were identified.
Progress towards the UNAIDS 90‐90‐90 targets among persons aged 50 and older living with HIV in 13 African countries

Achieving optimal HIV outcomes, as measured by global 90‐90‐90 targets, that is awareness of HIV‐positive status, receipt of antiretroviral (ARV) therapy among aware and viral load (VL) suppression among those on ARVs, respectively, is critical. However, few data from sub‐Saharan Africa (SSA) are available on older people (50+) living with HIV (OPLWH). We examined 90‐90‐90 progress by age, 15–49 (as a comparison) and 50+ years, with further analyses among 50+ (55–59, 60–64, 65+ vs. 50–54), in 13 countries (Cameroon, Cote d'Ivoire, Eswatini, Ethiopia, Kenya, Lesotho, Malawi, Namibia, Rwanda, Tanzania, Uganda, Zambia and Zimbabwe).
ASTROMETRIC EXOPLANET DETECTION WITH GAIA

We provide a revised assessment of the number of exoplanets that should be discovered by Gaia astrometry, extending previous studies to a broader range of spectral types, distances, and magnitudes. Our assessment is based on a large representative sample of host stars from the TRILEGAL Galaxy population synthesis model, recent estimates of the exoplanet frequency distributions as a function of stellar type, and detailed simulation of the Gaia observations using the updated instrument performance and scanning law. We use two approaches to estimate detectable planetary systems: one based on the signal-to-noise ratio of the astrometric signature per field crossing, easily reproducible and allowing comparisons with previous estimates, and a new and more robust metric based on orbit fitting to the simulated satellite data. With some plausible assumptions on planet occurrences, we find that some 21,000 (±6000) high-mass (∼1–15MJ) long-period planets should be discovered out to distances of ∼500 pc for the nominal 5 yr mission (including at least 1000–1500 around M dwarfs out to 100 pc), rising to some 70,000 (±20, 000) for a 10 yr mission. We indicate some of the expected features of this exoplanet population, amongst them ∼25–50 intermediate-period (P ∼ 2–3 yr) transiting systems.
Nodal and spectral minimal partitions -- The state of the art in 2015 --

In this article, we propose a state of the art concerning the nodal and spectral minimal partitions. First we focus on the nodal partitions and give some examples of Courant sharp cases. Then we are interested in minimal spectral partitions. Using the link with the Courant sharp situation, we can determine the minimal k-partitions for some particular domains. We also recall some results about the topology of regular partitions and Aharonov-Bohm approach. The last section deals with the asymptotic behavior of minimal k-partition.