Miracle-dz/UniFAR-FTUs huggingface dataset:
Testing different methods for atmospheric parameters determination. The case study of the Am star HD 71297

In this paper we present a detailed spectroscopic analysis of the suspected marginal Am star HD71297. Our goal is to test the accuracy of two different approaches to determine the atmospheric parameters effective temperature, gravity, projected rotational velocity, and chemical abundances. The methods used in this paper are: classical spectral synthesis and the Versatile Wavelength Analysis (VWA) software. Since our star is bright and very close to the Sun, we were able to determine its effective temperature and gravity directly through photometric, interferometric, and parallax measurements. The values found were taken as reference to which we compare the values derived by spectroscopic methods. Our analysis leads us to conclude that the spectroscopic methods considered in this study to derive fundamental parameters give consistent results, if we consider all the sources of experimental errors, that have been discussed in the text. In addition, our study shows that the spectroscopic results are quite as accurate as those derived from direct measurements. As for the specific object analyzed here, according to our analysis, HD71297 has chemical abundances not compatible with the previous spectral classification. We found moderate underabundances of carbon, sodium, magnesium, and iron-peak elements, while oxygen, aluminum, silicon, sulfur, and heavy elements (Z > 39) are solar in content. This chemical pattern has been confirmed by the calculations performed with both methods.
The 2XMMi/SDSS Galaxy Cluster Survey - II. The optically confirmed cluster sample and the LX – T relation

Aims. We compile a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton serendipitous source catalogue (2XMMi-DR3) with optical confirmation and redshift measurement from the Sloan Digital Sky Survey (SDSS). We present an analysis of the X-ray properties of this new sample with particular emphasis on the X-ray luminosity–temperature (LX − T ) relation. Methods. The X-ray cluster candidates were selected from the 2XMMi-DR3 catalogue in the footprint of the SDSS-DR7. We developed a finding algorithm to search for overdensities of galaxies at the positions of the X-ray cluster candidates in the photometric redshift space and to measure the redshifts of the clusters from the SDSS data. For optically confirmed clusters with good quality X-ray data we derived the X-ray flux, luminosity, and temperature from proper spectral fits, while the X-ray flux for clusters with low-quality X-ray data was obtained from the 2XMMi-DR3 catalogue. Results. The detection algorithm provides the photometric redshift of 530 galaxy clusters. Of these, 310 clusters have a spectroscopic redshift for at least one member galaxy. About 75 percent of the optically confirmed cluster sample are newly discovered X-ray clusters. Moreover, 301 systems are known as optically selected clusters in the literature while the remainder are new discoveries in X-ray and optical bands. The optically confirmed cluster sample spans a wide redshift range 0.03−0.70 (median z = 0.32). In this paper, we present the catalogue of X-ray-selected galaxy groups and clusters from the 2XMMi/SDSS galaxy cluster survey. The catalogue has two subsamples: (i) a cluster sample comprising 345 objects with their X-ray spectroscopic temperature and flux from the spectral fitting; and (ii) a cluster sample consisting of 185 systems with their X-ray flux from the 2XMMi-DR3 catalogue, because their X-ray data are insufficient for spectral fitting. For each cluster, the catalogue also provides the X-ray bolometric luminosity and the cluster mass at R500 based on scaling relations and the position of the likely brightest cluster galaxy (BCG). The updated LX − T relation of the current sample with X-ray spectroscopic parameters is presented. We found the slope of the LX − T relation to be consistent with published ones. We see no evidence for evolution in the slope and intrinsic scatter of the LX −T relation with redshift when excluding the low-luminosity groups.
Analysis of a-InGaZnO TFT Threshold Voltage Instability and Mobility Boosting by Current Stress at a Cryogenic Temperature

Device characteristics of amorphous InGaZnO thin film transistors (a-IGZO TFTs) at a cryogenic temperature (<inline-formula> <tex-math notation="LaTeX">${T}$ </tex-math></inline-formula>) are analyzed including device instability after applying current stress. Threshold voltage instability (<inline-formula> <tex-math notation="LaTeX">$\Delta {V}_{\mathrm{T}}$ </tex-math></inline-formula>) mechanisms are analyzed before and after applying stress in the two TFTs with different oxygen flow rates in the formation of a-IGZO active layers (O-poor and O-rich TFTs). <inline-formula> <tex-math notation="LaTeX">$\Delta {V}_{\mathrm{T}}$ </tex-math></inline-formula> of the a-IGZO TFTs at 77K are reduced less than 50% of that at 300K, because charge trapping into the gate insulator stack and the donor creation in the active layer are T- dependent processes. After applying stress at 77K, the O-poor TFT has better stability than the O-rich TFT, but the O-rich TFT exhibits a mobility boosting (<inline-formula> <tex-math notation="LaTeX">$\times 1.7$ </tex-math></inline-formula>) related to donor creation, which can increase the operating speed and reduce the operating voltage at a cryogenic <inline-formula> <tex-math notation="LaTeX">${T}$ </tex-math></inline-formula> operation.
Noisy propagation of coherent states in a lossy Kerr medium

We identify and discuss nonlinear phase noise arising in Kerr self-phase modulation of a coherent light pulse propagating through an attenuating medium with third-order nonlinearity in a dispersion-free setting. This phenomenon, accompanying the standard unitary Kerr transformation of the optical field, is described with high accuracy as Gaussian phase diffusion with parameters given by closed expressions in terms of system properties. We show that the irreversibility of the nonlinear phase noise ultimately limits the ability to transmit classical information in the phase variable over a lossy single-mode bosonic channel with Kerr-type nonlinearity. Our model can be also used to estimate the amount of squeezing attainable through self-phase modulation in a Kerr medium with distributed attenuation.
SWIFT DISCOVERY OF A NEW SOFT GAMMA REPEATER, SGR J1745−29, NEAR SAGITTARIUS A*

Starting in 2013 February, Swift has been performing short daily monitoring observations of the G2 gas cloud near Sgr A* with the X-Ray Telescope to determine whether the cloud interaction leads to an increase in the flux from the Galactic center. On 2013 April 24 Swift detected an order of magnitude rise in the X-ray flux from the region near Sgr A*. Initially thought to be a flare from Sgr A*, the detection of a short hard X-ray burst from the same region by the Burst Alert Telescope suggested that the flare was from an unresolved new Soft Gamma Repeater, SGR J1745−29. Here we present the discovery of SGR J1745−29 by Swift, including analysis of data before, during, and after the burst. We find that the spectrum in the 0.3–10 keV range is well fit by an absorbed blackbody model with kTBB ≃ 1 keV and absorption consistent with previously measured values from the quiescent emission from Sgr A*, strongly suggesting that this source is at a similar distance. Only one SGR burst has been detected so far from the new source, and the persistent light curve shows little evidence of decay in approximately two weeks of monitoring after outburst. We discuss this light curve trend and compare it with those of other well covered SGR outbursts. We suggest that SGR J1745-29 belongs to an emerging subclass of magnetars characterized by low burst rates and prolonged steady X-ray emission one to two weeks after outburst onset.
TESTING THE JET QUENCHING PARADIGM WITH AN ULTRADEEP OBSERVATION OF A STEADILY SOFT STATE BLACK HOLE

We present ultradeep radio observations with the Expanded Very Large Array of 4U 1957+11, a Galactic black hole (BH) candidate X-ray binary known to exist in a persistent soft X-ray state. We derive a stringent upper limit of 11.4 μJy beam−1 (3σ) at 5–7 GHz, which provides the most rigorous upper limit to date on the presence of jets in a soft state BH X-ray binary (BHXB). X-ray, UV, and optical fluxes obtained within a few weeks of the radio data can be explained by thermal emission from the disk. At this X-ray luminosity, a hard state BHXB that follows the established empirical radio–X-ray correlation would be at least 330–810 times brighter at radio frequencies, depending on the distance to 4U 1957+11. This jet quenching of >2.5 orders of magnitude is greater than some models predict and implies that the jets are prevented from being launched altogether in the soft state. 4U 1957+11 is also more than one order of magnitude fainter than the faintest of the “radio-quiet” population of hard state BHs. In addition, we show that, on average, soft state stellar-mass BHs probably have fainter jets than most active galactic nuclei in a state equivalent to the soft state. These results have implications for the conditions required for powerful, relativistic jets to form and provide a new empirical constraint for time- and accretion mode-dependent jet models, furthering our understanding of jet production and accretion onto BHs.
Structural, elastic, electronic, andoptical properties of layered TiNX (X = F, Cl, Br, I) compounds: a density functional theory study

ABSTRACT Titanium nitride halides, TiNX (X = F, Cl, Br, I) in the α-phase (orthorhombic) are exciting quasi two-dimensional (2D) electronic systems exhibiting a fascinating series of electronic ground states. Pristine TiNX are semiconductors with varying energy gaps and possess attractive properties for potential applications in optoelectronics, photovoltaics, and thermoelectrics. Alkali metal intercalated TiNCl becomes superconducting at reasonably high temperature. We have revisited the electronic band structure of TiNX using density functional theory (DFT) based calculations. The atomic orbital resolved partial electronic energy densities of states are calculated together with the total density of states (TDOS). The structural and elastic properties have been investigated in details for the first time. The elastic anisotropy has been explored. The optical properties of TiNX are studied for the first time. The Debye temperatures have been calculated and the related thermal and phonon parameters are discussed. The calculated physical parameters are compared with existing theoretical and experimental results and showed fair agreement. TiNX are found to reflect electromagnetic radiation strongly in the mid ultraviolet region. The elastic properties show high degree of anisotropy. The effect of halogen atoms on various structural, elastic, electronic, and thermal properties in TiNX are also discussed in detail. GRAPHICAL ABSTRACT
Effect of butanol additive with mango seed biodiesel and diesel ternary blends on performance and emission characteristics of diesel engine

ABSTRACT Current research investigates performance and emission characteristics of single cylinder 4-S diesel engine powered by different ternary fuel blends of diesel, mango seed (potential renewable feedstock of energy generation) biodiesel (MSB) and butanol (promising, sustainable, renewable and eco-friendly) oxygenated additive at different loading conditions experimentally. For the purpose, oil is extracted from discarded mango seeds through Soxhlet apparatus and biodiesel is prepared through transesterification process. Different blending mixture of MSB (fixed in 20%), diesel (80%, 75%, 70%, and 65%) and butanol (0%, 5%, 10%, and 15%) additive on their volume basis are prepared through magnetic stirring. These blends are named as MSB20B0, MSB20B5, MSB20B10, and MSB20B15, respectively. Experiment reveals that MSB20B5 lowers the BSFC by 25.79% and increases the BTE by 8.46% in comparison to MSB20B0 at maximum loading and approaching diesel fuel. In addition, MSB20B5 blend reduces the exhaust pollutants such as HC, NOx, CO2, and CO by 9.16%, 17.74%, 9.92%, and 13.33%, respectively, compared to MSB20B0 biodiesel blend at maximum loading. Overall, MSB20B5 ternary blend improves engine performance and reduce emissions hence recommended for diesels.
Perpendicular magnetic anisotropy of cobalt films intercalated under graphene

Magnetic properties of nanometer-thick Co films intercalated at the graphene/Ir(111) interface are investigated using spin-polarized low-energy electron microscopy and Auger electron spectroscopy. We show that the graphene top layer promotes perpendicular magnetic anisotropy in the Co film underneath, even for relatively thick intercalated deposits. The magnetic anisotropy energy is significantly larger for the graphene/Co interface than for the free Co surface. Hybridization of the graphene and Co electron orbitals is believed to be at the origin of the observed perpendicular magnetic anisotropy.
Further explorations of Skyrme-Hartree-Fock-Bogoliubov mass formulas. XII. Stiffness and stability of neutron-star matter

We construct three new Hartree-Fock-Bogoliubov (HFB) mass models, labeled HFB-19, HFB20, and HFB-21, with unconventional Skyrme forces containing t4 and t5 terms, i.e., densitydependent generalizations of the usual t1 and t2 terms, respectively. The new forces underlying these models are fitted respectively to three different realistic equations of state of neutron matter for which the density dependence of the symmetry energy ranges from the very soft to the very stiff, reflecting thereby our present lack of complete knowledge of the high-density behavior of nuclear matter. All unphysical instabilities of nuclear matter, including the transition to a polarized state in neutron-star matter, are eliminated with the new forces. At the same time the new models fit essentially all the available mass data with rms deviations of 0.58 MeV and give the same high quality fits to measured charge radii that we obtained in earlier models with conventional Skyrme forces. Being constrained by neutron matter, these new mass models, which all give similar extrapolations out to the neutron drip line, are highly appropriate for studies of the r-process and the outer crust of neutron stars. Moreover, the underlying forces, labeled BSk19, BSk20 and BSk21, respectively, are well adapted to the study of the inner crust and core of neutron stars. The new family of Skyrme forces thus opens the way to a unified description of all regions of neutron stars.
Evaluation of polarisability tensors of arbitrarily shaped highly conducting bodies

A full-wave numerical scheme of polarisability (polarisability) tensors evaluation is presented. The method accepts highly conducting bodies of arbitrary shape and explicitly accounts for the radiation as well as ohmic losses. The method is verified on canonical bodies with known polarisability tensors, such as a sphere and a cube, as well as on realistic scatterers. The theoretical developments are followed by a freely available code whose sole user input is the triangular mesh covering the surface of the body under consideration.
Large- and small-scale structure of the intermediate- and high-velocity clouds towards the LMC and SMC

We employ Caii K and Nai D interstellar absorption-line spectroscopy of earlytype stars in the Large and Small Magellanic Clouds to investigate the large- and small-scale structure in foreground Intermediate and High Velocity Clouds (I/HVCs). These data include FLAMES-GIRAFFE Caii K observations of 403 stars in four open clusters, plus FEROS or UVES spectra of 156 stars in the LMC and SMC. The FLAMES observations are amongst the most extensive probes to date of Caii structures on �20 arcsec scales in Magellanic I/HVCs. From the FLAMES data within a 0.5 ◦ field-of-view, the Caii K equivalent width in the I/HVC components towards three clusters varies by factors of �10. There are no detections of molecular gas in absorption at intermediate or high velocities, although molecular absorption is present at LMC and Galactic velocities towards some sightlines. The sightlines show variations in EW exceeding a factor �7 in CH + towards NGC1761 over scales of less than 10 arcminutes. The FEROS/UVES data show Caii K I/HVC absorption in �60 per cent of sightlines. No Nai D is found at non-Magellanic HVC velocities aside from a tentative detection towards the star LHA 120-S 93. The range in the Caii/Nai ratio in I/HVCs is from –0.45 to +1.5 dex, similar to previous measurements for I/HVCs. In ten sightlines we find Caii/Oi ratios in I/HVC gas ranging from 0.2 to 1.5 dex below the solar value, indicating either dust or ionisation effects. In nine sightlines I/HVC gas is detected in both Hi and Caii, and shows similar Caii/Hi ratios to typical I/HVCs, and similar velocities, implying that in these sightlines the two elements form part of the same structure.
Consistency of matter models with asymptotically safe quantum gravity

We discuss the compatibility of quantum gravity with dynamical matter degrees of freedom. Specifically, we present bounds we obtained in [1] on the allowed number and type of matter fields within asymptotically safe quantum gravity. As a novel result, we show bounds on the allowed number of spin-3/2 (Rarita-Schwinger) fields, e.g., the gravitino. These bounds, obtained within truncated Renormalization Group flows, indicate the compatibility of asymptotic safety with the matter fields of the standard model. Further, they suggest that extensions of the matter content of the standard model are severely restricted in asymptotic safety. This means that searches for new particles at colliders could provide experimental tests for this particular approach to quantum gravity.
First detection of CO in a high-redshift DLA

We present the first detection of carbon monoxide (CO) in a damped Lyman-alpha system (DLA) at z_abs =2.41837 toward SDSS J143912.04+111740.5. We also detected H_2 and HD molecules. The measured total column densities (in log units) of H I, H_2, and CO are 20.10\pm0.10, 19.38\pm0.10, and 13.89\pm0.02, respectively. The molecular fraction, f = 2N(H_2)/(N(HI)+2N(H_2)) = 0.27^{+0.10}_{-0.08}, is the highest among all known DLAs. The abundances relative to solar of S, Zn, Si, and Fe are -0.03\pm0.12, +0.16\pm0.11, -0.86\pm0.11, and -1.32\pm0.11, respectively, indicating a high metal enrichment and a depletion pattern onto dust-grains similar to the cold ISM of our Galaxy. The measured {N(CO)/N(H_2) = 3x10^{-6}} is much less than the conventional CO/H_2 ratio used to convert the CO emission into gaseous mass but is consistent with what is measured along translucent sightlines in the Galaxy. The CO rotational excitation temperatures are higher than those measured in our Galactic ISM for similar kinetic temperature and density. Using the C I fine structure absorption lines, we show that this is a consequence of the excitation being dominated by radiative pumping by the cosmic microwave background radiation (CMBR). From the CO excitation temperatures, we derive T_CMBR = 9.15 \pm 0.72 K, while 9.315 \pm 0.007 K is expected from the hot big-bang theory. This is the most precise high-redshift measurement of T_CMBR and the first confirmation of the theory using molecular transitions at high redshift.
Effects of anisotropic dynamics on cosmic strings

The dynamics of cosmic strings is considered in anisotropic backgrounds. In particular, the behaviour of infinitely long straight cosmic strings and of cosmic string loops is determined. Small perturbations of a straight cosmic string are calculated. The relevance of these results is discussed with respect to the possible observational imprints of an anisotropic phase on the behaviour of a cosmic string network.
The structure of the Mg ii broad line emitting region in Type 1 AGNs

We investigate the structure of the Mg II broad line emission region in a sample of 284 Type 1 active galactic nuclei (AGNs), through comparing the kinematical parameters of the broad Mg II and broad H$\beta$ lines. We found that the Mg II emitting region has more complex kinematics than the H$\beta$ one. It seems that the \ion{Mg}{ii} broad line originates from two subregions: one which contributes to the line core, which is probably virialized, and the other, 'fountain-like' emitting region, with outflows-inflows nearly orthogonal to the disc, which become suppressed with stronger gravitational influence. This subregion mostly contributes to the emission of the Mg II broad line wings. The kinematics of the Mg II core emitting region is similar to that of the H$\beta$ broad line region (seems to be virialized), and therefore the Full Width at Half Maximum (FWHM) of Mg II still can be used for the black hole (BH) mass estimation in the case where the Mg II core component is dominant. However, one should be careful with using the \ion{Mg}{ii} broad line for the BH mass estimation in the case of very large widths (FWHM$>$ 6000 km s$^{-1}$) and/or in the case of strong blue asymmetry.
The structure of the R8?> term in type IIB string theory

Based on the structure of the on-shell linearized superspace of type IIB supergravity, we argue that there is a non-BPS 16 derivative interaction in the effective action of type IIB string theory of the form (t8t8R4)2, which we call the R8? > interaction. It lies in the same supermultiplet as the G8R4? > interaction. Using the Kawai–Lewellen–Tye relation, we analyze the structure of the tree level eight-graviton scattering amplitude in the type IIB theory, which leads to the R8? > interaction at the linearized level. This involves an analysis of color-ordered multi-gluon disc amplitudes in the type I theory, which shows an intricate pole structure and transcendentality consistent with various other interactions. Considerations of S-duality show that the R8? > interaction receives non-analytic contributions in the string coupling at one and two loops. Apart from receiving perturbative contributions, we show that the R8? > interaction receives a non-vanishing contribution in the one D-instanton-anti-instanton background at leading order in the weak coupling expansion.
Quantum information processing in phase space: A modular variables approach

Binary quantum information can be fault tolerantly encoded in states defined in infinite dimensional Hilbert spaces. Such states define a computational basis, and permit a perfect equivalence between continuous and discrete universal operations. The drawback of this encoding is that the corresponding logical states are unphysical, meaning infinitely localized in phase space. We use the modular variables formalism to show that, in a number of protocols relevant for quantum information and for the realization of fundamental tests of quantum mechanics, it is possible to loosen the requirements on the logical subspace without jeopardizing their usefulness or their successful implementation. Such protocols involve measurements of appropriately chosen modular observables that permit the readout of the encoded discrete quantum information from the corresponding logical states. Finally, we demonstrate the experimental feasibility of our approach by applying it to the transverse degrees of freedom of single photons.