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2020-04-23
Chandra High Energy Transmission Gratings Spectra of V3890 Sgr
The recurrent nova (RN) V3890 Sgr was observed during the 7th day after the onset of its most recent outburst, with the Chandra ACIS-S camera and High Energy Transmission Gratings (HETG). A rich emission line spectrum was detected, due to transitions of Fe-L and K-shell ions ranging from neon to iron. The measured abso...
2004.11263v2
2020-05-19
ARES II: Characterising the Hot Jupiters WASP-127 b, WASP-79 b and WASP-62 b with HST
This paper presents the atmospheric characterisation of three large, gaseous planets: WASP-127b, WASP-79b and WASP-62b. We analysed spectroscopic data obtained with the G141 grism (1.088 - 1.68 $\mu$m) of the Wide Field Camera 3 (WFC3) onboard the Hubble Space Telescope (HST) using the Iraclis pipeline and the TauREx3 ...
2005.09615v2
2020-05-29
Cold, dry, windy, and UV irradiated -- surveying Mars relevant conditions in Ojos del Salado Volcano (Andes Mountains, Chile)
The Special Collection of papers in this issue of Astrobiology provide an overview of the characteristics and potential for future exploration of the Ojos del Salado volcano, located in the Andes Mountains in front of the Atacama Desert in northern Chile. The main benefits of this site compared with others are the comb...
2005.14450v1
2020-06-05
Chemically peculiar A and F stars with enhanced s-process and iron-peak elements: stellar radiative acceleration at work
We present $\gtrsim 15,000$ metal-rich (${\rm [Fe/H]}>-0.2$dex) A and F stars whose surface abundances deviate strongly from Solar abundance ratios and cannot plausibly reflect their birth material composition. These stars are identified by their high [Ba/Fe] abundance ratios (${\rm [Ba/Fe]}>1.0$dex) in the LAMOST DR5 ...
2006.03329v1
2020-06-29
Impact of the returning radiation on the analysis of the reflection spectra of black holes
A fraction of the electromagnetic radiation emitted from the surface of a geometrically thin and optically thick accretion disk of a black hole returns to the disk because of the strong light bending in the vicinity of the compact object (returning radiation). While such radiation clearly affects the observed spectrum ...
2006.15838v2
2020-07-02
Iron in X-COP: tracing enrichment in cluster outskirts with high accuracy abundance profiles
We present the first metal abundance profiles for a representative sample of massive clusters. Our measures extend to $R_{500}$ and are corrected for a systematic error plaguing previous outskirt estimates. Our profiles flatten out at large radii, admittedly not a new result, however the radial range and representative...
2007.01084v1
2020-07-21
Unveiling the Planet Population at Birth
The radius distribution of small, close-in exoplanets has recently been shown to be bimodal. The photoevaporation model predicted this bimodality. In the photoevaporation scenario, some planets are completely stripped of their primordial H/He atmospheres, whereas others retain them. Comparisons between the photoevapora...
2007.11006v2
2020-07-24
The Most Metal-poor Stars in the Inner Bulge
The bulge is the oldest component of the Milky Way. Since numerous simulations of Milky Way formation have predicted that the oldest stars at a given metallicity are found on tightly bound orbits, the Galaxy's oldest stars are likely metal-poor stars in the inner bulge with small apocenters (i.e., $R_{\mathrm{apo}}\les...
2007.12728v1
2021-02-01
Connecting the Light Curves of Type IIP Supernovae to the Properties of their Progenitors
Observations of core-collapse supernovae (CCSNe) reveal a wealth of information about the dynamics of the supernova ejecta and its composition but very little direct information about the progenitor. Constraining properties of the progenitor and the explosion requires coupling the observations with a theoretical model ...
2102.01118v2
2021-06-09
Turbulent transport of impurities in 3D devices
A large diffusive turbulent contribution to the radial impurity transport in Wendelstein 7-X (W7-X) plasmas has been experimentally inferred during the first campaigns and numerically confirmed by means of gyrokinetic simulations with the code stella. In general, the absence of strong impurity accumulation during the i...
2106.05017v2
2021-06-21
Correlations Among STM Observables in Disordered Unconventional Superconductors
New developments in scanning tunneling spectroscopy now allow for the spatially resolved measurement of the Josephson critical current $I_c$ between a tip and a superconducting sample, a nearly direct measurement of the true superconducting order parameter. However, it is unclear how these $I_c$ measurements are correl...
2106.11091v2
2021-06-24
X-ray Emission of the $γ$-ray Loud Young Radio Galaxy NGC 3894
The radio source 1146+596 is hosted by an elliptical/S0 galaxy NGC\,3894, with a low-luminosity active nucleus. The radio structure is compact, suggesting a very young age of the jets in the system. Recently, the source has been confirmed as a high-energy (HE, $>0.1$\,GeV) $\gamma$-ray emitter, in the most recent accum...
2106.13193v2
2021-06-30
The Inhomogeneity of Composition along the Magnetic Cloud Axis
It is generally accepted that CMEs result from eruptions of magnetic flux ropes, which are dubbed as magnetic clouds in interplanetary space. The composition (including the ionic charge states and elemental abundances) is determined prior to and/or during CME eruptions in the solar atmosphere, and does not alter during...
2106.15834v1
2021-06-30
Spectroscopy and photometry of the least-massive Type-II globular clusters: NGC1261 AND NGC6934
Recent work has revealed two classes of Globular Clusters (GCs), dubbed Type-I and Type-II. Type-II GCs are characterized by a blue- and a red- red giant branch composed of stars with different metallicities, often coupled with distinct abundances in the slow-neutron capture elements (s-elements). Here we continue the ...
2106.15978v1
2021-07-02
Ti I lines at 2.2 $μ$m as probes of the cool parts of sunspots
The sunspot umbra harbors the coolest plasma on the solar surface due to the presence of strong magnetic fields. The routinely used atomic lines to observe the photosphere have weak signals in the umbra and are often swamped by molecular lines. This makes it harder to infer the properties of the umbra, especially in th...
2107.01247v1
2022-07-23
Data Adaptive Regularization for Abdominal Quantitative Susceptibility Mapping
Purpose: To improve repeatability and reproducibility across acquisition parameters and reduce bias in quantitative susceptibility mapping (QSM) of the liver, through development of an optimized regularized reconstruction algorithm for abdominal QSM. Theory and Methods: An optimized approach to estimation of magnetic...
2207.11416v1
2022-07-27
The breakdown of both strange metal and superconducting states at a pressure-induced quantum critical point in iron-pnictide superconductors
The strange metal (SM) state, characterized by a linear-in-temperature resistivity, is often seen in the normal state of high temperature superconductors. It is believed that the SM state is one of the keys to understand the underlying mechanism of high-Tc superconductivity. Here we report the first observation of the ...
2207.13272v2
2017-05-29
Baby MIND: A magnetized segmented neutrino detector for the WAGASCI experiment
T2K (Tokai-to-Kamioka) is a long-baseline neutrino experiment in Japan designed to study various parameters of neutrino oscillations. A near detector complex (ND280) is located 280~m downstream of the production target and measures neutrino beam parameters before any oscillations occur. ND280's measurements are used to...
1705.10406v3
2017-06-15
$η$ Carinae's Dusty Homunculus Nebula from Near-Infrared to Submillimeter Wavelengths: Mass, Composition, and Evidence for Fading Opacity
Infrared observations of the dusty, massive Homunculus Nebula around the luminous blue variable $\eta$ Carinae are crucial to characterize the mass-loss history and help constrain the mechanisms leading to the Great Eruption. We present the 2.4 - 670 $\mu$m spectral energy distribution, constructed from legacy ISO obse...
1706.05112v1
2017-06-29
X-shooter spectroscopy of young stellar objects in Lupus: Lithium, iron, and barium elemental abundances
With the purpose of performing a homogeneous determination of elemental abundances for members of the Lupus T association, we analyzed three chemical elements: lithium, iron, and barium. The aims were: to derive the Li abundance for ~90% of known class II stars in the Lupus I, II, III, IV clouds; to perform chemical ta...
1706.09684v1
2018-02-02
Spectral Evidence for Amorphous Silicates in Least-processed CO Meteorites and Their Parent Bodies
Least-processed carbonaceous chondrites (carbonaceous chondrites that have experienced minimal aqueous alteration and thermal metamorphism) are characterized by their predominately amorphous iron-rich silicate interchondrule matrices and chondrule rims. The presence of abundant amorphous material in a meteorite indicat...
1802.00830v1
2018-02-08
Orbital Origin of Extremely Anisotropic Superconducting Gap in Nematic Phase of FeSe Superconductor
The iron-based superconductors are characterized by multiple-orbital physics where all the five Fe 3$d$ orbitals get involved. The multiple-orbital nature gives rise to various novel phenomena like orbital-selective Mott transition, nematicity and orbital fluctuation that provide a new route for realizing superconducti...
1802.02940v1
2018-02-13
Probing the use of spectroscopy to determine the meteoritic analogues of meteors
Determining the source regions of meteorites is one of the major goals of current research in planetary science. Whereas asteroid observations are currently unable to pinpoint the source regions of most meteorite classes, observations of meteors with camera networks and the subsequent recovery of the meteorite may help...
1802.04699v2
2018-02-14
Hydrodynamical Neutron-star Kicks in Electron-capture Supernovae and Implications for the CRAB Supernova
Neutron stars (NSs) obtain kicks of typically several 100 km/s at birth. The gravitational tug-boat mechanism can explain these kicks as consequences of asymmetric mass ejection during the supernova (SN) explosion. Support for this hydrodynamic explanation is provided by observations of SN remnants with associated NSs,...
1802.05274v2
2018-02-21
Can the relativistic light bending model explain X-ray spectral variations of Seyfert galaxies?
Many Seyfert galaxies are known to exhibit Fe-K broad emission line features in their X-ray energy spectra. The observed lines have three distinct features; (1) the line profiles are skewed and show significant low-energy tails, (2) the Fe-K band have low variability, which produces a broad and deep dip in the root-mea...
1802.07554v2
2018-02-21
Broad absorption line symbiotic stars: highly ionized species in the fast outflow from MWC 560
In symbiotic binaries, jets and disk winds may be integral to the physics of accretion onto white dwarfs from cool giants. The persistent outflow from symbiotic star MWC 560 (=V694 Mon) is known to manifest as broad absorption lines (BALs), most prominently at the Balmer transitions. We report the detection of high-ion...
1802.07743v2
2018-02-28
Late metal-silicate separation on the IAB parent asteroid: Constraints from combined W and Pt isotopes and thermal modelling
The short-lived $^{182}$Hf-$^{182}$W decay system is a powerful chronometer for constraining the timing of metal-silicate separation and core formation in planetesimals and planets. Neutron capture effects on W isotopes, however, significantly hamper the application of this tool. In order to correct for neutron capture...
1802.10421v1
2018-07-05
V902 Monocerotis: a likely disc-accreting intermediate polar
Aims: We aim to confirm whether the eclipsing cataclysmic variable V902 Mon is an Intermediate Polar, to characterise its X-ray spectrum and flux, and to refine its orbital ephemeris and spin period. Methods: We performed spectrographic observations of V902 Mon in 2016 with the 2.2m Calar Alto telescope, and X-ray phot...
1807.01981v1
2018-07-05
Mineralogy, structure and habitability of carbon-enriched rocky exoplanets: A laboratory approach
Carbon-enriched rocky exoplanets have been proposed around dwarf stars as well as around binary stars, white dwarfs and pulsars. However, the mineralogical make up of such planets is poorly constrained. We performed high-pressure high-temperature laboratory experiments ($P$ = 1$-$2 GPa, $T$ = 1523$-$1823 K) on carbon-e...
1807.02064v2
2018-07-10
X-shooting GRBs at high redshift: probing dust production history
Evolved asymptotic giant branch (AGB) stars and Type Ia supernovae (SNe) are important contributors to the elements that form dust in the interstellar medium of galaxies, in particular, carbon and iron. However, they require at least a Gyr to start producing these elements, therefore, a change in dust quantity or prope...
1807.03597v1
2018-07-18
Optical dimming of RW Aur associated with an iron rich corona and exceptionally high absorbing column density
RW Aur is a binary system composed of two young, low-mass stars. The primary, RW Aur A, has undergone visual dimming events ($\Delta V =2-3$~mag) in 2011, 2014-16, and 2017-2018. Visual and IR observations indicate a gray absorber that moved into the line-of-sight. This dimming is also associated with changes in the ou...
1807.06995v1
2018-07-25
APOGEE Data Releases 13 and 14: Stellar Parameter and Abundance Comparisons With Independent Analyses
Data from the SDSS-IV / Apache Point Observatory Galactic Evolution Experiment (APOGEE-2) have been released as part of SDSS Data Releases 13 (DR13) and 14 (DR14). These include high resolution H-band spectra, radial velocities, and derived stellar parameters and abundances. DR13, released in August 2016, contained APO...
1807.09784v1
2018-08-01
Nebular-phase spectra of superluminous supernovae: physical insights from observational and statistical properties
We study the spectroscopic evolution of superluminous supernovae (SLSNe) later than 100 days after maximum light. We present new data for Gaia16apd and SN2017egm, and analyse these with a larger sample comprising 41 spectra of 12 events. The spectra become nebular within 2-4 $e$-folding times after light curve peak, wi...
1808.00510v2
2018-10-24
Fe I in the Beta Pictoris circumstellar gas disk. II. The time variations in the iron circumstellar gas
Beta Pictoris is a young planetary system surrounded by a debris disk of dust and gas. The gas source of this disk could be exocomets (or 'falling and evaporating bodies', FEBs), which produce refractory elements (Mg, Ca, Fe) through sublimation of dust grains at several tens of stellar radii. Nearly 1700 high resoluti...
1810.10421v1
2019-01-17
Emergence of Superconductivity from Fully Incoherent Normal State in an Iron-Based Superconductor (Ba$_{0.6}$K$_{0.4}$)Fe$_2$As$_2$
In unconventional superconductors, it is generally believed that understanding the physical properties of the normal state is a pre-requisite for understanding the superconductivity mechanism. In conventional superconductors like niobium or lead, the normal state is a Fermi liquid with a well-defined Fermi surface and ...
1901.05693v1
2019-01-24
Anisotropic magnetic excitations and incipient Néel order in Ba(Fe$_{1-x}$Mn$_{x}$)$_{2}$As$_{2}$
It is currently understood that high temperature superconductivity (SC) in the transition metal $(M)$ substituted iron arsenides Ba(Fe$_{1-x}$$M$$_{x}$)$_{2}$As$_{2}$ is promoted by magnetic excitations with wave vectors $(\pi,0)$ or $(0,\pi)$. It is known that while a small amount of Co substitution leads to SC, the s...
1901.08543v3
2019-04-09
CsMn$_4$As$_3$: A layered tetragonal transition-metal pnictide compound with antiferromagnetic ground state
We report the synthesis and properties of a new layered tetragonal ternary compound CsMn$_4$As$_3$ (structure: KCu$_4$S$_3$-type, space group: $P4/mmm$, No. 123 and $Z = 2$). The material is a small band-gap semiconductor and exhibits an antiferromagnetic ground state associated with Mn spins. The compound exhibits a s...
1904.04598v1
2019-04-09
Insulating Parent Phase and Distinct Doping Evolution to Superconductivity in Single-Layer FeSe/SrTiO3 Films
The single-layer FeSe/SrTiO3 (FeSe/STO) films have attracted much attention because of their simple crystal structure, distinct electronic structure and record high superconducting transition temperature (Tc). The origin of the dramatic Tc enhancement in single-layer FeSe/STO films and the dichotomy of superconductivit...
1904.04662v1
2019-06-19
Iron abundance distribution in the hot gas of merging galaxy clusters
We present XMM-Newton/EPIC observations of six merging galaxy clusters and study the distributions of their temperature, iron (Fe) abundance and pseudo-entropy along the merging axis. For the first time, we focus simultaneously, and in a comprehensive way, on the chemical and thermodynamic properties of the freshly col...
1906.08067v1
2019-07-02
Neutron star mergers and rare core-collapse supernovae as sources of r-process enrichment in simulated galaxies
We use cosmological, magnetohydrodynamical simulations of Milky Way-mass galaxies from the Auriga project to study their enrichment with rapid neutron capture (r-process) elements. We implement a variety of enrichment models from both binary neutron star mergers and rare core-collapse supernovae. We focus on the abunda...
1907.01557v2
2019-07-17
Heavy metals in intermediate He-rich hot subdwarfs: The chemical composition of HZ44 and HD127493
Hot subluminous stars can be spectroscopically classified as subdwarf B (sdB) and O (sdO) stars. While the latter are predominantly hydrogen deficient, the former are mostly helium deficient. The atmospheres of most sdOs are almost devoid of hydrogen, whereas a small group of hot subdwarf stars of mixed H/He compositio...
1907.07781v1
2019-07-29
Turbulence and Rotation in Solar-Type Stars
Stellar spectra with a high resolution of 115000 obtained with the HARPS spectrograph provide an opportunity to examine turbulence velocities and their depth distributions in the photosphere of stars. Fourier analysis was performed for 17 iron lines in the spectra of 13 stars with an effective temperature of 4900--6200...
1907.12241v1
2019-10-07
Optical and photoemission investigation of structural and magnetic transitions in the iron-based superconductor Sr$_\mathbf{0.67}$Na$_\mathbf{0.33}$Fe$_\mathbf{2}$As$_\mathbf{2}$
We report the temperature-dependent optical conductivity and ARPES studies of the iron-based superconductor (SC) Sr$_{0.67}$Na$_{0.33}$Fe$_2$As$_2$ in the high-temperature tetragonal paramagnetic phase; below the structural and magnetic transitions at $T_{\rm N}\simeq$125 K in the orthorhombic spin-density-wave (SDW)-l...
1910.02927v2
2019-10-28
Type Ia Supernova Explosions from Hybrid Carbon-Oxygen-Neon White Dwarf Progenitors That Have Mixed During Cooling
The creation of "hybrid" white dwarfs, made of a C-O core within a O-Ne shell has been proposed, and studies indicate that ignition in the C-rich central region makes these viable progenitors for thermonuclear (type Ia) supernovae. Recent work found that the C-O core is mixed with the surrounding O-Ne as the white dwar...
1910.12403v1
2019-12-15
The influence of NLTE effects in Fe I lines on an inverted atmosphere I. 6301 A and 6302 A lines formed in 1D NLTE
Ultraviolet over-ionisation of iron atoms in the solar atmosphere leads to deviations in their level populations from the Saha-Boltzmann statistics. This causes their line profiles to form in Non-Local Thermodynamic Equilibrium (NLTE) conditions. While inverting such profiles to determine atmospheric parameters, the NL...
1912.07007v2
2020-03-06
Studying the Reflection Spectra of the New Black Hole X-ray Binary Candidate MAXI J1631-479 Observed by NuSTAR: A Variable Broad Iron Line Profile
We present results from the Nuclear Spectroscopic Telescope Array (NuSTAR) observations of the new black hole X-ray binary candidate MAXI J1631-479 at two epochs during its 2018-2019 outburst, which caught the source in a disk dominant state and a power-law dominant state. Strong relativistic disk reflection features a...
2003.03465v1
2020-08-04
The infancy of core-collapse supernova remnants
We present 3D hydrodynamic simulations of neutrino-driven supernovae (SNe) with the PROMETHEUS-HOTB code, evolving the asymmetrically expanding ejecta from shock breakout until they reach the homologous expansion phase after roughly one year. Our calculations continue the simulations for two red supergiant (RSG) and tw...
2008.01763v2
2020-08-13
On the detection of surface spin freezing in iron oxide nanoparticles and its long-term evolution under ambient oxidation
Exchange bias effects linked to surface spin freezing (SSF) are commonly found in iron oxide nanoparticles, while signatures of SSF in low-field temperature-dependent magnetization curves have been much less frequently reported. Here, we present magnetic properties of dense assemblies of similar-sized (~ 8 nm diameter)...
2008.05874v1
2020-08-31
Structural, magnetic and electronic properties of CaBaCo4-xMxO7 (M= Fe, Zn)
The effect of substituting iron and zinc for cobalt in CaBaCo$_4$O$_7$ has been investigated using neutron diffraction and x-ray absorption spectroscopy. The orthorhombic distortion present in the parent compound CaBaCo$_4$O$_7$ decreases with increasing the content of either Fe or Zn. The samples CaBaCo$_3$ZnO$_7$ and...
2008.13649v1
2020-10-14
The X-SHOOTER/ALMA sample of Quasars in the Epoch of Reionization. I. NIR spectral modeling, iron enrichment and broad emission line properties
We present X-SHOOTER near-infrared spectroscopy of a large sample of 38 luminous ($M_{1450}=-29.0$ to $-24.4$) quasars at $5.78<z<7.54$, which have complementary CII observations from ALMA. This X-SHOOTER/ALMA sample provides us with the most comprehensive view of reionization-era quasars to date, allowing us to connec...
2010.06902v1
2020-10-21
Composition and origin of L5 Trojan asteroids of Mars: Insights from spectroscopy
We investigate the mineralogy of L5 Martian Trojan asteroids via reflectance spectroscopy, in particular (101429) 1998 $\mbox{VF}_{31}$, the only L5 Trojan that does not belong to the Eureka family (Christou, 2013). We find that this asteroid most likely belongs to the Bus-Demeo S-complex, in agreement with Rivkin et a...
2010.10947v1
2020-10-29
Spectroscopic Evidence of Superconductivity Pairing at 83 K in Single-Layer FeSe/SrTiO3 Films
Single-layer FeSe films grown on the SrTiO3 substrate (FeSe/STO) have attracted much attention because of their possible record-high superconducting critical temperature Tc and distinct electronic structures in iron-based superconductors. However, it has been under debate on how high its Tc can really reach due to the ...
2010.15362v1
2020-11-03
Discovery of a Fast Iron Low-ionization Outflow in the Early Evolution of the Nearby Tidal Disruption Event AT2019qiz
We report the results of ultraviolet (UV) and optical photometric and spectroscopic analysis of the tidal disruption event (TDE) AT2019qiz. Our follow-up observations started $<$10 days after the source began to brighten in the optical and lasted for a period of six months. Our late-time host-dominated spectrum indicat...
2011.01593v2
2020-11-15
Three-dimensional Supernova Models Provide New Insights into the Origins of Stardust
We present the isotope yields of two post-explosion, three-dimensional 15 $M_\odot$ core-collapse supernova models, 15S and 15A, and compare them to the carbon, nitrogen, silicon, aluminum, sulfur, calcium, titanium, iron, and nickel isotopic compositions of SiC stardust. We find that these core-collapse supernova mode...
2011.07459v2
2020-11-25
Light Quantum Control of Persisting Higgs Modes in Iron-Based Superconductors
The Higgs mechanism, i.e., spontaneous symmetry breaking of the quantum vacuum, is a cross-disciplinary principle, universal for understanding dark energy, antimatter and quantum materials, from superconductivity to magnetism. Yet, Higgs modes in one-band superconductors (SCs) are currently under debate due to their co...
2011.13036v2
2020-11-27
XMM-Newton observations of the extremely X-ray luminous quasar CFHQS J142952+544717=SRGE J142952.1+544716 at redshift z=6.18
We present results from a 20 ks XMM-Newton DDT observation of the radio-load quasar CFHQS J142952+544717 at z=6.18, whose extreme X-ray luminosity was recently revealed by the SRG/eROSITA telescope in the course of its first all-sky survey. The quasar has been confidently detected with a total of $\sim 1400$ net counts...
2011.13724v2
2020-12-02
Synthesis and Characterization of Sodium Iron Antimonate Na2FeSbO5 One-Dimensional Antiferromagnetic Chain Compound with a Spin Glass Ground State
A new oxide, sodium iron antimonate, Na2FeSbO5, was synthesized and structurally characterized, and its static and dynamic magnetic properties were comprehensively studied both experimentally by dc and ac magnetic susceptibility, magnetization, specific heat, electron spin resonance (ESR) and Moessbauer measurements, a...
2012.01106v1
2021-01-02
Influence of NLTE effects in Fe I lines on inverted atmosphere II. 6301 A and 6302 A lines formed in 3DNLTE
This paper forms the second part of our study on how the neglect of NLTE conditions in the formation of Fe I 6301.5 A and the 6302.5 A lines influences the atmosphere obtained by inverting their profiles in LTE. The main cause of NLTE effects is the line opacity deficit due to the excess ionization of the Fe I atoms by...
2101.00506v1
2021-01-24
Exploring the diversity of double detonation explosions for type Ia supernovae: Effects of the post-explosion helium shell composition
The detonation of a helium shell on top of a carbon-oxygen white dwarf has been argued as a potential explosion mechanism for type Ia supernovae (SNe~Ia). The ash produced during helium shell burning can lead to light curves and spectra that are inconsistent with normal SNe~Ia, but may be viable for some objects showin...
2101.09792v1
2021-03-12
Chemical analysis of the Bulge Globular Cluster NGC 6553
Globular Clusters are among the oldest objects in the Galaxy, thus their researchers are key to understanding the processes of evolution and formation that the galaxy has experienced in early stages. Spectroscopic studies allow us to carry out detailed analyzes on the chemical composition of Globular Clusters. The aim ...
2103.07014v1
2021-04-03
Genuine Electronic Structure and Superconducting Gap Structure in (Ba$_{0.6}$K$_{0.4}$)Fe$_{2}$As$_{2}$ Superconductor
The electronic structure and superconducting gap structure are prerequisites to establish microscopic theories in understanding the superconductivity mechanism of iron-based superconductors. However, even for the most extensively studied optimally-doped (Ba$_{0.6}$K$_{0.4}$)Fe$_2$As$_2$, there remain outstanding contro...
2104.01407v1
2021-05-04
The Effect of Geometry, Spin and Orbital Optimization in Achieving Accurate, Fully-Correlated Results for Iron-Sulfur Cubanes
Iron-sulfur clusters comprise an important functional motif of the catalytic centers of biological systems, capable of enabling important chemical transformations at ambient conditions. This remarkable capability derives from a notoriously complex electronic structure that is characterized by a high density of states t...
2105.01754v2
2021-05-10
Cloud busting: enstatite and quartz clouds in the atmosphere of 2M2224-0158
We present the most detailed data-driven exploration of cloud opacity in a substellar object to-date. We have tested over 60 combinations of cloud composition and structure, particle size distribution, scattering model, and gas phase composition assumptions against archival $1-15 {\rm \mu m}$ spectroscopy for the unusu...
2105.04268v1
2021-05-13
Near-Room-Temperature Ferromagnetic Behavior of Single-Atom-Thick 2D Iron in Nanolaminated Ternary MAX Phases
Two dimensional (2D) ferromagnetic materials have attracted much attention in the fields of condensed matter physics and materials science, but their synthesis is still a challenge given their limitations on structural stability and susceptibility to oxidization. MAX phases nanolaminated ternary carbides or nitrides po...
2105.06139v1
2021-05-26
Magnetic Particle Spectroscopy (MPS) with One-stage Lock-in Implementation for Magnetic Bioassays with Improved Sensitivities
In recent years, magnetic particle spectroscopy (MPS) has become a highly sensitive and versatile sensing technique for quantitative bioassays. It relies on the dynamic magnetic responses of magnetic nanoparticles (MNPs) for the detection of target analytes in liquid phase. There are many research studies reporting the...
2105.12718v1
2021-09-13
The stellar mass versus stellar metallicity relation of star-forming galaxies at $1.6\le z\le3.0$ and implications for the evolution of the $α$-enhancement
We measure the relationship between stellar mass and stellar metallicity, the stellar mass--metallicity relation (MZR), for 1336 star-forming galaxies at $1.6\le z\le3.0$ (<z>=2.2) using rest-frame far-ultraviolet spectra from the zCOSMOS-deep survey. High signal-to-noise composite spectra containing stellar absorption...
2109.06044v1
2021-09-28
Stable nickel production in Type Ia supernovae: A smoking gun for the progenitor mass?
At present, there are strong indications that white dwarf (WD) stars with masses well below the Chandrasekhar limit (MCh ~ 1.4 Msun) contribute a significant fraction of SN Ia progenitors. The relative fraction of stable iron-group elements synthesized in the explosion has been suggested as a possible discriminant betw...
2109.13840v3
2021-10-17
The iron and oxygen content of LMC Classical Cepheids and its implications for the Extragalactic Distance Scale and Hubble constant
Classical Cepheids are primary distance indicators and a crucial stepping stone to determining the present-day Hubble constant Ho to the precision and accuracy required to constrain apparent deviations from the LCDM Concordance Cosmological Model. We have measured the iron and oxygen abundances of of 89 Cepheids in the...
2110.08860v2
2022-01-05
Phase-resolved spectroscopy of a quasi-periodic oscillation in the black hole X-ray binary GRS 1915+105 with NICER and NuSTAR
Quasi-periodic oscillations (QPOs) are often present in the X-ray flux from accreting stellar-mass black holes (BHs). If they are due to relativistic (Lense-Thirring) precession of an inner accretion flow which is misaligned with the disc, the iron emission line caused by irradiation of the disc by the inner flow will ...
2201.01765v1
2022-01-24
Formation of Zn and Pb sulfides in a redox-sensitive modern system due to high atmospheric fallout
The study shows that the air-derived metal enrichment (up to 2.3 g Zn kg-1, 1.1 g Pb kg-1, and 62 mg Cd kg-1) is retained in a thin layer (~30 cm) around 10-15 cm below the peat surface. A combination of focused ion beam (FIB) technology and scanning (SEM) and transmission (TEM) electron microscopy reveals that microme...
2201.09552v1
2022-02-14
Giant Impact onto a Vesta-Like Asteroid and Formation of Mesosiderites through Mixing of Metallic Core and Surface Crust
Mesosiderites are a type of stony-iron meteorites composed of a mixture of silicates and Fe-Ni metals. The mesosiderite silicates and metals are considered to have originated from the crust and metal core, respectively, of a differentiated asteroid. In contrast, mesosiderites rarely contain the olivine that is mainly i...
2202.06486v1
2022-02-16
Spin Seebeck effect in iron oxide thin films: Effects of phase transition, phase coexistence, and surface magnetism
Understanding impacts of phase transition, phase coexistence, and surface magnetism on the longitudinal spin Seebeck effect (LSSE) in a magnetic system is essential to manipulate the spin to charge current conversion efficiency for spincaloritronic applications. We aim to elucidate these effects by performing a compreh...
2202.07910v1
2022-02-16
A new and homogeneous metallicity scale for Galactic classical Cepheids II. The abundance of iron and alpha elements
Classical Cepheids are the most popular distance indicators and tracers of young stellar populations. The key advantage is that they are bright and they can be easily identified in Local Group and Local Volume galaxies. Their evolutionary and pulsation properties depend on their chemical abundances. The main aim of thi...
2202.07945v1
2022-03-01
Low-luminosity type IIP supernovae: SN 2005cs and SN 2020cxd as very low-energy iron core-collapse explosions
SN 2020cxd is a representative of the family of low-energy, underluminous Type IIP supernovae (SNe), whose observations and analysis were recently reported by Yang et al. (2021). Here we re-evaluate the observational data for the diagnostic SN properties by employing the hydrodynamic explosion model of a 9 MSun red sup...
2203.00473v2
2022-03-06
Coupling between the accreting corona and the relativistic jet in the micro quasar GRS 1915+105
GRS 1915+105 was the first stellar-mass black-hole in our Galaxy to display a superluminal radio jet, similar to those observed in active galactic nuclei with a supermassive black hole at the centre. It has been proposed that the radio emission in GRS 1915+105 is fed by instabilities in the accretion disc by which the ...
2203.02963v1
2022-03-07
The in situ origin of the globular cluster NGC 6388 from abundances of Sc, V, and Zn of a large sample of stars
Chemical tagging of globular clusters (GCs) is often done using abundances of alpha-elements. The iron-peak elements Sc, V, and in particular Zn were proposed as an alternative to alpha-elements to tag accreted GCs in the metal-rich regime, where the dwarf galaxy Sagittarius and its GCs show peculiarly marked under-abu...
2203.03645v1
2022-03-22
Co-loading of doxorubicin and iron oxide nanocubes in polycaprolactone fibers for combining Magneto-Thermal and chemotherapeutic effects on cancer cells
Among the strategies to fight cancer, multi-therapeutic approaches are considered as a wise choice to put in place multiple weapons to suppress tumors. In this work, to combine chemotherapeutic effects to magnetic hyperthermia when using biocompatible scaffolds, we have established an electrospinning method to produce ...
2203.12380v1
2022-03-23
Prospects of measuring a metallicity trend and spread in globular clusters from low-resolution spectroscopy
The metallicity spread, or the metallicity trend along the evolutionary sequence of a globular cluster, is a rich source of information to help understand the cluster physics (e.g. multiple populations) and stellar physics (e.g. atomic diffusion). Low-resolution integral-field-unit spectroscopy in the optical with the ...
2203.12685v1
2022-03-30
The p-process in exploding rotating massive stars
The p-process nucleosynthesis can explain proton-rich isotopes that are heavier than iron, which are observed in the Solar System, but discrepancies still persist and important questions concerning the astrophysical site(s) of the p-process remain unanswered. We investigate how the p-process operates in exploding rotat...
2203.16380v1
2022-04-11
The GAPS Programme at TNG XXXIII. HARPS-N detects multiple atomic species in emission from the dayside of KELT-20b
The detection of lines in emission in planetary atmospheres provides direct evidence of temperature inversion. We confirm the trend of ultra-hot Jupiters orbiting A-type stars showing temperature inversions on their daysides, by detecting metals emission lines in the dayside of KELT-20b. We first detect the planetary e...
2204.04948v1
2022-05-19
Nuclear Weak Rates and Nuclear Weak Processes in Stars
Nuclear weak rates in stellar environments are obtained by shell-model calculations including Gamow-Teller (GT) and spin-dipole transitions, and applied to nuclear weak processes in stars. The important roles of accurate weak rates for the study of astrophysical processes are pointed out. The weak rates in $sd$-shell a...
2205.09262v2
2022-06-29
Does the Fe L-shell blend bias abundance measurements in intermediate-temperature clusters?
In intermediate-temperature (T = 2.5 - 4.5 keV) galaxy clusters, abundance measurements are almost-equally driven by Fe K and L transitions, at $\sim$ 6.7 keV and 0.9 - 1.3 keV, respectively. While K-shell-derived measurements are considered reliable, the resolution of the currently available instrumentation, as well a...
2206.14827v1
2022-08-08
The chemical abundance pattern of the extremely metal-poor thin disk star 2MASS J1808-5104 and its origins
We present a high-resolution ($R\sim35,000$), high signal-to-noise ($S/N=350$) Magellan/MIKE spectrum of the bright extremely metal-poor star 2MASS~J1808$-$5104. We find [Fe/H] = $-$4.01 (spectroscopic LTE stellar parameters), [Fe/H] = $-$3.8 (photometric stellar parameters), [Fe/H] = $-$3.7 (spectroscopic NLTE stellar...
2208.03891v1
2022-09-02
An intermediate polar candidate toward the Galactic plane
For the past decade, it has been suggested that intermediate polars (IPs), a subclass of magnetic cataclysmic variables (CVs), are one of the main contributors to the hard diffuse X-ray emission from the Galactic center (GC) and Galactic ridge. In our ongoing \emph{XMM-Newton} survey of the central region of the Galact...
2209.00970v1
2022-09-12
53Mn-53Cr chronology and ε54Cr-Δ17O genealogy of Erg Chech 002: the oldest andesite in the Solar System
The meteorite sample Erg Chech (EC) 002 is the oldest felsic igneous rock from the Solar System analysed to date and provides a unique opportunity to study the formation of felsic crusts on differentiated protoplanets immediately after metal-silicate equilibration or core formation. The extinct 53Mn-53Cr chronometer pr...
2209.05381v1
2022-09-13
The Puzzle of Meteoritic Minerals Heideite and Brezinaite; Are they Iron-based Superconductors? Are they Technosignatures?
Transition metal sulfides (Fe, V)3S4 and (Fe, Ti)3S4, with the monoclinic Cr3S4 type structure have been studied for a long time, itinerant magnetism in form of Spin density waves (SDW) have been found in these systems with different features as evidenced by 57Fe Mossbauer Spectroscopy, there is an intricate relationsh...
2209.05679v1
2022-10-11
Ironing the folds: The phase space chevrons of a GSE-like merger as a dark matter subhalo detector
Recent work uncovered features in the phase space of the Milky Way's stellar halo which may be attributed to the last major merger. When stellar material from a satellite is accreted onto its host, it phase mixes and appears finely substructured in phase space. For a high-eccentricity merger, this substructure most cle...
2210.05679v2
2022-10-13
TOI-561 b: A Low Density Ultra-Short Period "Rocky" Planet around a Metal-Poor Star
TOI-561 is a galactic thick disk star hosting an ultra-short period (0.45 day orbit) planet with a radius of 1.37 R$_{\oplus}$, making it one of the most metal-poor ([Fe/H] = -0.41) and oldest ($\sim$10 Gyr) sites where an Earth-sized planet has been found. We present new simultaneous radial velocity measurements (RVs)...
2210.06665v3
2022-10-14
The homogeneity of chemical abundances in H II regions of the Magellanic Clouds
We use very deep spectra obtained with the Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope to derive physical conditions and chemical abundances of four H II regions of the Large Magellanic Cloud (LMC) and four H II regions of the Small Magellanic Cloud (SMC). The observations cover the spectral ran...
2210.07460v1
2022-11-11
The unaltered pulsar: GRO J1750-27, a super-critical X-ray neutron star that does not blink an eye
When accreting X-ray pulsars (XRPs) undergo bright X-ray outbursts, their luminosity-dependent spectral and timing features can be analysed in detail. The XRP GRO J1750-27 recently underwent one of such episodes, during which it was observed with $NuSTAR$ and monitored with $NICER$. Such a data set is rarely available,...
2211.06367v2
2022-12-01
Three dimensional magnetorotational core-collapse supernova explosions of a 39 solar mass progenitor star
We perform three-dimensional simulations of magnetorotational supernovae using a $39\,M_{\odot}$ progenitor star with two different initial magnetic field strengths of $10^{10}$ G and $10^{12}$ G in the core. Both models rapidly undergo shock revival and their explosion energies asymptote within a few hundred milliseco...
2212.00200v3
2022-12-12
Systematic Broad-band X-ray Study of super-Eddington Accretion onto Supermassive Black Holes. I. X-ray Continuum
We present the first systematic broad-band X-ray study of super-Eddington accretion onto SMBHs with simultaneous {\it NuSTAR} and {\it XMM-Newton} or {\it Swift}/XRT observations of a sample of 8 super-Eddington accreting AGN with Eddington ratio $1<\lambda_{\rm Edd}<426$. We find that the SEAMBHs show a steep primary ...
2212.06183v1
2022-12-15
Non-trivial band topology and orbital-selective electronic nematicity in a new titanium-based kagome superconductor
Electronic nematicity that spontaneously breaks rotational symmetry has been shown as a generic phenomenon in correlated quantum systems including high-temperature superconductors and the AV3Sb5 (A = K, Rb, Cs) family with a kagome network. Identifying the driving force has been a central challenge for understanding ne...
2212.07958v1
2023-01-20
The chemical DNA of the Magellanic Clouds -- I. The chemical composition of 206 Small Magellanic Cloud red giant stars
We present the chemical composition of 206 red giant branch stars members of the Small Magellanic Cloud (SMC) using optical, high-resolution spectra collected with the multi-object spectrograph FLAMES-GIRAFFE at the ESO Very Large Telescope. This sample includes stars in three fields located in different positions with...
2301.08758v1
2023-01-30
The Hubble/STIS Near-ultraviolet Transmission Spectrum of HD 189733b
The benchmark hot Jupiter HD 189733b has been a key target to lay out the foundations of comparative planetology for giant exoplanets. As such, HD 189733b has been extensively studied across the electromagnetic spectrum. Here, we report the observation and analysis of three transit light curves of HD 189733b obtained w...
2301.13025v1
2023-01-30
A Catalog of 71 Coronal Line Galaxies in MaNGA: [NeV] is an Effective AGN Tracer
Despite the importance of AGN in galaxy evolution, accurate AGN identification is often challenging, as common AGN diagnostics can be confused by contributions from star formation and other effects (e.g., Baldwin-Phillips-Terlevich diagrams). However, one promising avenue for identifying AGNs are ``coronal emission lin...
2301.13322v1
2023-02-09
Chaotic winds from a dying world: a one-dimensional map for evolving atmospheres
Planets which are smaller than Mercury and heated to sublimation temperatures of $\sim$2000 K lose mass catastrophically in dusty evaporative winds. The winds are observed to gust and recede largely without pattern; transit depths from the Kepler mission vary randomly from orbit to orbit by up to a factor of 10 or more...
2302.04898v2
2023-03-02
Concurrent Ferromagnetism and Superconductivity in Fe(Te,Se) van der Waals Josephson Junctions
Ferromagnetism and superconductivity are two key ingredients to create non-Abelian quasiparticle excitations that are expected as building blocks to construct topological quantum computers. Adversely, ferromagnetism and superconductivity are typically also two hostile orderings competing to align spins in different con...
2303.00966v2
2023-03-19
$\rm Li_x(C_5H_5N)_yFe_{2-z}Se_2$: a defect resilient expanded-lattice high-temperature superconductor
Two-dimensional iron-chalcogenide intercalates display a remarkable correlation of the interlayer spacing with the enhancement of the superconducting critical temperature ($T_c$). In this work, synchrotron x-ray absorption ($XAS$, at Fe and Se K edges) and emission ($XES$) spectroscopies, allow to discuss how the impor...
2303.10716v1
2023-05-02
Lunar Mantle Structure and Composition Inferred From Apollo 12 -- Explorer 35 Electromagnetic Sounding
Constraints on the interior of the Moon have been derived from its inductive response, principally as measured by the magnetic transfer function (TF) between the distantly orbiting Explorer 35 satellite and the Apollo 12 surface station. The most successful prior studies used a dataset spanning 0.01-1 mHz, so the lunar...
2305.01462v2