Miracle-dz/UniFAR-FTUs huggingface dataset:
Follow-up observations of extremely metal-poor stars identified from SDSS

The most metal-poor stars in the Milky Way witnessed the early phases of formation of the Galaxy, and have chemical compositions that are close to the pristine mixture from Big Bang nucleosynthesis, polluted by one or few supernovae. Only two dozen stars with ([Fe/H]< -4) are known, and they show a wide range of abundance patterns. It is therefore important to enlarge this sample. We present the first results of an effort to identify new extremely metal-poor stars in the Milky Way halo. Our targets have been selected from low-resolution spectra obtained as part of the Sloan Digital Sky Survey, and followed-up with medium resolution spectroscopy on the 4.2 m William Herschel Telescope and, in a few cases, at high resolution on the the 9.2 m Hobby-Eberly Telescope. Stellar parameters and the abundances of magnesium, calcium, iron, and strontium have been inferred from the spectra using classical model atmospheres. We have also derived carbon abundances from the G band. We find consistency between the metallicities estimated from SDSS and those from new data at the level of 0.3 dex. The analysis of medium resolution data obtained with ISIS on the WHT allow us to refine the metallicities and in some cases measure other elemental abundances. Our sample contains 11 new metal-poor stars with [Fe/H] < -3.0, one of them with an estimated metallicity of [Fe/H] ~ -4.0. We also discuss metallicity discrepancies of some stars in common with previous works in the literature. Only one of these stars is found to be C-enhanced at about [C/Fe]~+1, whereas the other metal-poor stars show C abundances at the level of [C/Fe]~+0.45.
Which Hydrogen Balmer Lines Are Most Reliable for Determining White Dwarf Atmospheric Parameters

Our preliminary results from laboratory experiments studying white dwarf (WD) photospheres show a systematic difference between experimental plasma conditions inferred from measured H$\beta$ absorption line profiles versus those from H$\gamma$. One hypothesis for this discrepancy is an inaccuracy in the relative theoretical line profiles of these two transitions. This is intriguing because atmospheric parameters inferred from H Balmer lines in observed WD spectra show systematic trends such that inferred surface gravities decrease with increasing principal quantum number, $n$. If conditions inferred from lower-$n$ Balmer lines are indeed more accurate, this suggests that spectroscopically determined DA WD masses may be greater than previously thought and in better agreement with the mean mass determined from gravitational redshifts.
Surface density of dark matter haloes on galactic and cluster scales

In this paper, in the framework of the secondary infall model, the correlation between the central surface density and the halo core radius of galaxy, and cluster of galaxies, dark matter haloes was analyzed, this having recently been studied on a wide range of scales. We used Del Popolo (2009) secondary infall model taking into account ordered and random angular momentum, dynamical friction, and dark matter (DM) adiabatic contraction to calculate the density profile of haloes, and then these profiles are used to determine the surface density of DM haloes. The main result is that $r_\ast$ (the halo characteristic radius) is not an universal quantity as claimed by Donato et al. (2009) and Gentile et al. (2009). On the contrary, we find a correlation with the halo mass $M_{200}$ in agreement with Cardone & Tortora (2010), Boyarsky at al. (2009) and Napolitano et al. (2010), but with a significantly smaller scatter, namely $0.16 \pm 0.05$. We also consider the baryon column density finding this latter being indeed a constant for low mass systems such as dwarfs, but correlating with mass with a slope $\alpha= 0.18 \pm 0.05$. In the case of the surface density of dark matter for a system composed only of dark matter, as in dissipationless simulations, we get $\alpha=0.20 \pm 0.05$. These results leave little room for the recently claimed universality of (dark and stellar) column density.
Cutaneous Eruptions in the Course of COVID-19 Among Geriatric Patients in a Nursing Home in Poland

Purpose The aim of this study was to assess the incidence and characteristics of COVID-19 cutaneous manifestations among geriatric patients infected with the SARS-CoV-2 virus. Patients and Methods Sixty-four nursing home residents in Dobre Miasto, Poland (mean age: 79 years) infected with SARS-CoV-2 were monitored for skin lesions during the epidemic outbreak in 2020. Only five of them presented COVID-19 dermatological manifestation: vesicular (4 cases) and erythematous (1 case) skin lesions, which appeared after the remaining symptoms of the disease had resolved. Results The average time between COVID-19 onset and cutaneous manifestation was 22 days. Skin lesions persisted in five cases 112, 17, 21,19 and 27 days, respectively, and were often accompanied by pruritus and neuropathic pain. Conclusion Skin manifestations of SARS-CoV-2 infection might be misdiagnosed or overlooked, particularly among elderly patients with chronic diseases. The recognition of skin lesions due to COVID-19 might improve patients’ quality of life by reducing the intensity of symptoms such as pruritus or neuropathic pain.
Young and middle age pulsar light-curve morphology: Comparison of Fermi observations with γ-ray and radio emission geometries

Thanks to the huge amount of gamma-ray pulsar photons collected by the Fermi Large Area Telescope since June 2008, it is now possible to constrain gamma-ray geometrical models by comparing simulated and observed light-curve morphological characteristics. We assumed vacuum-retarded dipole pulsar magnetic field and tested simulated and observed morphological light-curve characteristics in the framework of two pole emission geometries, Polar Cap (PC), radio, and Slot Gap (SG), and Outer Gap (OG)/One Pole Caustic (OPC) emission geometries. We compared simulated and observed/estimated light-curve morphological parameters as a function of observable and non-observable pulsar parameters. The PC model gives the poorest description of the LAT pulsar light-curve morphology. The OPC best explains both the observed gamma-ray peak multiplicity and shape classes. The OPC and SG models describe the observed gamma-ray peak-separation distribution for low- and high-peak separations, respectively. This suggests that the OPC geometry best explains the single-peak structure but does not manage to describe the widely separated peaks predicted in the framework of the SG model as the emission from the two magnetic hemispheres. The OPC radio-lag distribution shows higher agreement with observations suggesting that assuming polar radio emission, the gamma-ray emission regions are likely to be located in the outer magnetosphere. The larger agreement between simulated and LAT estimations in the framework of the OPC suggests that the OPC model best predicts the observed variety of profile shapes. The larger agreement between observations and the OPC model jointly with the need to explain the abundant 0.5 separated peaks with two-pole emission geometries, calls for thin OPC gaps to explain the single-peak geometry but highlights the need of two-pole caustic emission geometry to explain widely separated peaks.
Contribution of ultracompact dark matter minihalos to the isotropic radio background

The ultracompact minihalos could be formed during the earlier epoch of the Universe. The dark matter annihilation within them is very strong due to the steep density profile, rho similar to r(-2.25). The high-energy electrons and positrons from the dark matter annihilation can inverse Compton scatter with the background photons, such as cosmic microwave background photons, to acquire higher energy. On the other hand, the synchrotron radiation can also be produced when they meet the magnetic field. In this paper, we study the signals from the ultracompact minihalos (UCMHs) due to the dark matter annihilation for the radio, x-ray and gamma-ray band. We found that for the radio emission, the UCMHs can provide one kind of source for the radio excess observed by ARCADE 2. But the x-ray signals due to the inverse Compton scatter effect or the gamma-ray signals mainly due to the prompt emission from dark matter would exceed the present observations, such as Fermi, COMPTEL, and CHANDRA. We found that the strongest limits on the fraction of UCMHs come from the x-ray observations, and the constraints from the radio data are the weakest. DOI: 10.1103/PhysRevD.87. 083519
Smoothed particle magnetohydrodynamics with a Riemann solver and the method of characteristics

In this paper, we develop a new method for magnetohydrodynamics (MHD) using smoothed particle hydrodynamics (SPH). To describe MHD shocks accurately, the Godunov method is applied to SPH instead of artificial dissipation terms. In the interaction between particles, we solve a non-linear Riemann problem with magnetic pressure for compressive waves and apply the method of characteristics for Alfven waves. An extensive series of MHD test calculations is performed. In all test calculations, we compare the results of our SPH code with those of a finite-volume method with an approximate Riemann solver, and confirm excellent agreement.
COMPARISON OF CONVECTIVE OVERSHOOTING MODELS AND THEIR IMPACT ON ABUNDANCES FROM INTEGRATED LIGHT SPECTROSCOPY OF YOUNG (<3 Gyr) STAR CLUSTERS

As part of an ongoing program to measure detailed chemical abundances in nearby galaxies, we use a sample of young- to intermediate-age clusters in the Large Magellanic Cloud with ages of 10 Myr–2 Gyr to evaluate the effect of isochrone parameters, specifically core convective overshooting, on Fe abundance results from high-resolution, integrated light spectroscopy. In this work we also obtain fiducial Fe abundances from high-resolution spectroscopy of the cluster individual member stars. We compare the Fe abundance results for the individual stars to the results from isochrones and integrated light spectroscopy to determine whether isochrones with convective overshooting should be used in our integrated light analysis of young- to intermediate-age (10 Myr–3 Gyr) star clusters. We find that when using the isochrones from the Teramo group, we obtain more accurate results for young- and intermediate-age clusters over the entire age range when using isochrones without convective overshooting. While convective overshooting is not the only uncertain aspect of stellar evolution, it is one of the most readily parameterized ingredients in stellar evolution models, and thus important to evaluate for the specific models used in our integrated light analysis. This work demonstrates that our method for integrated light spectroscopy of star clusters can provide unique tests for future constraints on stellar evolution models of young- and intermediate-age clusters.
Quantum metrology with imperfect states and detectors

Quantum enhancements of precision in metrology can be compromised by system imperfections. These may be mitigated by appropriate optimization of the input state to render it robust, at the expense of making the state difficult to prepare. In this paper, we identify the major sources of imperfection of an optical sensor: input state preparation inefficiency, sensor losses, and detector inefficiency. The second of these has received much attention; we show that it is the least damaging to surpassing the standard quantum limit in a optical interferometric sensor. Further, we show that photonic states that can be prepared in the laboratory using feasible resources allow a measurement strategy using photon-number-resolving detectors that not only attain the Heisenberg limit for phase estimation in the absence of losses, but also deliver close to the maximum possible precision in realistic scenarios including losses and inefficiencies. In particular, we give bounds for the tradeoff between the three sources of imperfection that will allow true quantum-enhanced optical metrology
Knowledge, Attitude and Practice (KAP) on Nutrition among Rural Farm Women of Chickballapur District of Karnataka, India

The present study was carried out with the objectives to assess Knowledge, Attitude, and Practice (KAP) of rural farm women on nutrition along with personal, socio economic profile. A total of 200 rural farm women from five villages of Shidlaghatta block, Chickballapur district, Karnataka, India were selected purposively for the study as Chikkaballapur district falls in the Eastern dry climatic zone and about 76% of the net sown area is under rainfed condition. Random sampling technique was used for the selection of the respondents. The data on socio-economic status, personnel characteristics and nutritional Knowledge, Attitude and Practice of the subjects were collected through a pre tested questionnaire. Study results reveals that 44.5% of the rural farm women belongs to middle age, 28.0% had high school education followed by 24.0% illiterate. Majority (93.0%) are married, most (63.5%) of them have agriculture as main occupation, More than half (53.0%) belongs to nuclear family, 47.5% have small family, nearly three fourth (69.0%) have 2-4 earners in the family. About 53.5% have marginal land holdings followed by 27.5% small, 65.0% belong to medium family income, 65.5% had medium mass media exposure, and 70.5% had medium level of extension contact. More than one third (34.5 %) of the rural farm women had high knowledge, followed by low (33.5%) and medium (32.0%). Thirty six percent had less favorable attitude towards nutrition, whereas 34.0% had favorable attitude and 30.0% had more favorable attitude. In case of nutrition practice 40.0% had poor practice, 35.5% had fair practice, and 24.5% had good practice. From present study it is concluded that there was more knowledge of rural farm women on nutritional aspects, less favorable attitude and poor practice of nutrition. Hence, intervention strategies like promotion of Nutri-gardens in Schools, Households and the rural Community, promotion of Nutri-sensitive crops or biofortified crops to address the malnutrition, promotion of Nutrition Thali through integrated farming system model, Awareness programmes or modules to educate the farm families for cultivation of nutri crops or bio-fortified crops and their nutritional importance and Nutritional deficiencies and its prevention through ICT, skill trainings for development of value added products or Nutrification of traditional recipes, encourage farm families to develop value added products and establish microenterprises to achieve economic security, convergence with all line departments (Women and Child welfare, Agriculture, Horticulture, Fisheries, livestock departments, health department etc.) for achieving the food, nutrition and health security of rural farm women.
GAS ACCRETION FROM A CIRCUMBINARY DISK

A new computational scheme is developed to study gas accretion from a circumbinary disk. The scheme decomposes the gas velocity into two components one of which denotes the Keplerian rotation and the other of which does the deviation from it. This scheme enables us to solve the centrifugal balance of a gas disk against gravity with better accuracy, since the former inertia force cancels the gravity. It is applied to circumbinary disk rotating around binary of which primary and secondary has mass ratio, 1.4:0.95. The gravity is reduced artificially softened only in small circular regions around the primary and secondary. The radii are 7% of the binary separation and much smaller than those in the previous grid based simulations. Seven models are constructed to study dependence on the gas temperature and the initial inner radius of the disk. The gas accretion shows both fast and slow time variations while the binary is assumed to have a circular orbit. The time variation is due to oscillation of spiral arms in the circumbinary disk. The masses of primary and secondary disks increase while oscillating appreciably. The mass accretion rate tends to be higher for the primary disk although the secondary disk has a higher accretion rate in certain periods. The accretion rates onto the two components are similar within the fluctuations in late times, i.e., after the binary rotates more than 20 times. The primary disk is perturbed intensely by the impact of gas flow so that the outer part is removed. The secondary disk is quiet in most of time on the contrary. Both the primary and secondary disks have traveling spiral waves which transfer angular momentum within them.
Timeline of Oxygen Demand in Patients with COVID-19 Pneumonia

Objective In patients with coronavirus disease 2019 (COVID-19), understanding the timeline of oxygen demand and severe respiratory failure, such as intensive care unit (ICU) admission, may clarify the therapeutic window when home-care treatment is possible and help determine the timing of treatment in hospitalized patients to improve the respiratory status. We examined the timeline of respiratory status in hospitalized patients with moderate-to-severe COVID-19 in terms of oxygen demand and ICU admission. Methods We retrospectively assessed all patients with COVID-19 who were admitted to our hospital between February 2020 and February 2021 and required supplemental oxygen. This study included 66 patients who were transferred to the ICU (ICU patients) and 144 patients who were not transferred to the ICU (non-ICU patients). Results In the total cohort, the median duration from symptom onset to the need for supplemental oxygen was 8 [interquartile range (IQR) 6-10] days. This duration was significantly shorter in ICU patients than in non-ICU patients [8 (IQR 6-9) vs. 9 (IQR 6-10) days, p=0.02]. The median duration from symptom onset to ICU admission was 9 (IQR 8-11) days in severely ill patients. The median duration from the initiation of supplemental oxygen to ICU admission was 1.0 (IQR 1-2.75) days. Only 2 of 66 patients (3.0%) were admitted to the ICU six days or later after the initiation of supplemental oxygen. Conclusion Physicians should carefully monitor each patient's condition after eight days from symptom onset. New therapies and their early administration are needed to reduce the frequency of respiratory failure in COVID-19 patients.
Kinetic simulations of magnetic reconnection in presence of a background O+ population

[1] Particle-in-Cell simulations of magnetic reconnection with an H+ current sheet and a mixed background plasma of H+ and O+ ions are completed using physical mass ratios. Four main results are shown. First, the O+ presence slightly decreases the reconnection rate and the magnetic reconnection evolution depends mainly on the lighter H+ ion species in the presented simulations. Second, the Hall magnetic field is characterized by a two-scale structure in presence of O+ ions: it reaches sharp peak values in a small area in proximity of the neutral line, and then decreases slowly over a large region. Third, the two background species initially separate in the outflow region because H+ and O+ ions are accelerated by different mechanisms occurring on different timescales and with different strengths. Fourth, the effect of a guide field on the O+ dynamics is studied: the O+ presence does not change the reconnected flux and all the characteristic features of guide field magnetic reconnection are still present. Moreover, the guide field introduces an O+ circulation pattern between separatrices that enhances high O+ density areas and depletes low O+ density regions in proximity of the reconnection fronts. The importance and the validity of these results are finally discussed.
FRAGMENTATION OF MASSIVE DENSE CORES DOWN TO ≲ 1000 AU: RELATION BETWEEN FRAGMENTATION AND DENSITY STRUCTURE

In order to shed light on the main physical processes controlling fragmentation of massive dense cores, we present a uniform study of the density structure of 19 massive dense cores, selected to be at similar evolutionary stages, for which their relative fragmentation level was assessed in a previous work. We inferred the density structure of the 19 cores through a simultaneous fit of the radial intensity profiles at 450 and 850 μm (or 1.2 mm in two cases) and the spectral energy distribution, assuming spherical symmetry and that the density and temperature of the cores decrease with radius following power-laws. Even though the estimated fragmentation level is strictly speaking a lower limit, its relative value is significant and several trends could be explored with our data. We find a weak (inverse) trend of fragmentation level and density power-law index, with steeper density profiles tending to show lower fragmentation, and vice versa. In addition, we find a trend of fragmentation increasing with density within a given radius, which arises from a combination of flat density profile and high central density and is consistent with Jeans fragmentation. We considered the effects of rotational-to-gravitational energy ratio, non-thermal velocity dispersion, and turbulence mode on the density structure of the cores, and found that compressive turbulence seems to yield higher central densities. Finally, a possible explanation for the origin of cores with concentrated density profiles, which are the cores showing no fragmentation, could be related with a strong magnetic field, consistent with the outcome of radiation magnetohydrodynamic simulations.
DISTRIBUTION OF CCS AND HC3N IN L1147, AN EARLY PHASE DARK CLOUD

We used the Nobeyama 45 m radio telescope to reveal spatial distributions of CCS and HC3N in L1147, one of the carbon-chain producing region (CCPR) candidates, where carbon-chain molecules are dominant rather than NH3. We found that three cores (two CCS cores and one HC3N core), which are away from a very low luminosity object (a source that may turn into a sub-stellar mass brown dwarf), exist along the NE–SW filament traced by the 850 μm dust continuum. The column densities of CCS are 3–7 × 1012 cm−2 and those of HC3N are 2–6 × 1012 cm−2, respectively, much lower than those previously reported toward other CCPRs. We also found that two CCS peaks are displaced from the peaks of HC3N. In order to interpret such interleaved distributions, we conducted chemical reaction network simulations and found that slightly different gas densities could lead to large variation of the CCS-to-HC3N ratio in the early phase of dark cloud evolution. Such a chemical “variation” may be seen in other CCPRs. Finally, we were able to confirm that the L1147 filament can be regarded as a CCPR.