publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
|---|---|---|---|
2010-04-26 | Chemical Abundances for the Outer Halo Cluster Pal 4 from Co-added High-Resolution Spectroscopy | Context: Chemical element abundances for distant Galactic globular clusters
(GCs) hold important clues to the origin of the Milky Way halo and its
substructures. Aims: We study the chemical composition of red giant stars in
Pal 4 - one of the most remote GCs in the Milky Way - and compare our abundance
measurements to ... | 1004.4625v1 |
2010-06-05 | Variations in the X-ray eclipse transitions of Cen X-3 | We report here an investigation of the X-ray eclipse transitions of the high
mass X-ray binary pulsar Cen X-3 in different intensity states. Long term light
curve of Cen X-3 obtained with RXTE-ASM spanning for more than 5000 days shows
strong aperiodic flux variations with low and high states. We have investigated
the ... | 1006.1035v1 |
2010-06-17 | The supernova delay time distribution in galaxy clusters and implications for Type-Ia progenitors and metal enrichment | Knowledge of the supernova (SN) delay time distribution (DTD) - the SN rate
versus time that would follow a hypothetical brief burst of star formation -
can shed light on SN progenitors and physics. We compile recent measurements of
the Type-Ia SN (SN Ia) rate in galaxy clusters at redshifts z=0-1.45. Together
with the... | 1006.3576v3 |
2010-08-01 | Chemical Enrichment in the Faintest Galaxies: the Carbon and Iron Abundance Spreads in the Boötes I Dwarf Spheroidal Galaxy and the Segue 1 System | We present an AAOmega spectroscopic study of red giant stars in Bootes I,
which is an ultra-faint dwarf galaxy, and Segue 1, suggested to be either an
extremely low-luminosity dwarf galaxy or a star cluster. Our focus is
quantifying the mean abundance and abundance dispersion in iron and carbon, and
searching for dista... | 1008.0137v1 |
2010-11-29 | New Atomic Data for Trans-Iron Elements and Their Application to Abundance Determinations in Planetary Nebulae | [Abridged] Investigations of neutron(n)-capture element nucleosynthesis and
chemical evolution have largely been based on stellar spectroscopy. However,
the recent detection of these elements in several planetary nebulae (PNe)
indicates that nebular spectroscopy is a promising new tool for such studies.
In PNe, n-captu... | 1011.6311v1 |
2011-03-31 | The metal contents of two groups of galaxies | The hot gas in clusters and groups of galaxies is continuously being enriched
with metals from supernovae and stars. It is well established that the
enrichment of the gas with elements from oxygen to iron is mainly caused by
supernova explosions. The origins of nitrogen and carbon are still being
debated. Possible cand... | 1104.0001v1 |
2011-04-11 | Self-consistent spin-wave theory for a frustrated Heisenberg model with biquadratic exchange in the columnar phase and its application to iron pnictides | Recent neutron scattering studies revealed the three dimensional character of
the magnetism in the iron pnictides and a strong anisotropy between the
exchange perpendicular and parallel to the spin stripes. We extend studies of
the J1-J2-Jc Heisenberg model with S = 1 using self-consistent spin-wave
theory. A discussio... | 1104.1954v2 |
2011-04-22 | K-shell Emission of Neutral Iron Line from Sgr B2 Excited by Subrelativistic Protons | We investigated the emission of K$\alpha$ iron line from the massive
molecular clouds in the Galactic center (GC). We assume that at present the
total flux of this emission consists of time variable component generated by
primary X-ray photons ejected by Sagittarius A$^\ast$ (Sgr A$^\ast$) in the
past and a relatively ... | 1104.4484v1 |
2011-07-05 | A giant planet in the triple system HD132563 | As part of our radial velocity planet-search survey performed with SARG at
TNG, we monitored the components of HD 132563 for ten years. It is a binary
system formed by two rather similar solar type stars with a projected
separation of 4.1 arcsec, which corresponds to 400 AU at the distance of 96 pc.
The two components ... | 1107.0918v1 |
2011-11-21 | Iron and alpha-element Production in the First One Billion Years after the Big Bang | We present measurements of carbon, oxygen, silicon, and iron in quasar
absorption systems existing when the universe was roughly one billion years
old. We measure column densities in nine low-ionization systems at 4.7 < z <
6.3 using Keck, Magellan, and VLT optical and near-infrared spectra with
moderate to high resolu... | 1111.4843v1 |
2012-01-04 | Synthesis and physical properties of the new potassium iron selenide superconductor K0.80Fe1.76Se2 | In this article we review our studies of the K0.80Fe1.76Se2 superconductor,
with an attempt to elucidate the crystal growth details and basic physical
properties over a wide range of temperatures and applied magnetic field,
including anisotropic magnetic and electrical transport properties,
thermodynamic, London penetr... | 1201.0953v2 |
2012-02-13 | A Variable Partial Covering Model for the Seyfert 1 Galaxy MCG-6-30-15 | We propose a simple spectral model for the Seyfert 1 Galaxy MCG-6-30-15 that
can explain most of the 1 - 40 keV spectral variation by change of the partial
covering fraction, similar to the one proposed by Miller et al. (2008). Our
spectral model is composed of three continuum components; (1) a direct
power-law compone... | 1202.2797v3 |
2012-02-23 | The Similarity of Broad Iron Lines in X-ray Binaries and Active Galactic Nuclei | We have compared the 2001 XMM-Newton spectra of the stellar mass black hole
binary XTE J1650-500 and the active galaxy MGC-6-30-15, focusing on the broad,
excess emission features at ~4--7 keV displayed by both sources. Such features
are frequently observed in both low mass X-ray binaries and active galactic
nuclei. Fo... | 1202.5193v1 |
2012-03-02 | Testing the effects of opacity and the chemical mixture on the excitation of pulsations in B stars of the Magellanic Clouds | The B-type pulsators known as \beta Cephei and Slowly Pulsating B (SPB) stars
present pulsations driven by the \kappa mechanism, which operates thanks to an
opacity bump due to the iron group elements. In low-metallicity environments
such as the Magellanic Clouds, \beta Cep and SPB pulsations are not expected.
Neverthe... | 1203.0527v1 |
2012-03-19 | Hot Gas in Galaxy Groups: Recent Observations | Galaxy groups are the least massive systems where the bulk of baryons begin
to be accounted for. Not simply the scaled-down versions of rich clusters
following self-similar relations, galaxy groups are ideal systems to study
baryon physics, which is important for both cluster cosmology and galaxy
formation. We review t... | 1203.4228v1 |
2012-03-28 | Dependence of the structural and physical properties of Tl1-yFe2-z(Se1-xSx)2 with isovalent substitution of Se by S: decrease of TNeel with S content | The effect of selenium substitution by sulfur or tellurium in the
Tl1-yFe2-zSe2 antiferromagnet was studied by x-ray and electron diffraction,
magnetization and transport measurements. Tl0.8Fe1.5(Se1-xXx)2 (nominal
composition) solid solutions were synthesized in the full x range (0<x<1) for
X=S and up to x=0.5 for X=T... | 1203.6181v2 |
2012-05-21 | Very High Resolution Solar X-ray Imaging Using Diffractive Optics | This paper describes the development of X-ray diffractive optics for imaging
solar flares with better than 0.1 arcsec angular resolution. X-ray images with
this resolution of the \geq10 MK plasma in solar active regions and solar
flares would allow the cross-sectional area of magnetic loops to be resolved
and the coron... | 1205.4762v1 |
2012-07-04 | Nematic and meta-nematic transitions in the iron pnictides | Strongly interacting electrons can exhibit novel collective phases, among
which the electronic nematic phases are perhaps the most surprising as they
spontaneously break rotational symmetry of the underlying crystal lattice. The
electron nematicity has been recently observed in the iron-pnictide and cuprate
high-temper... | 1207.1045v1 |
2012-08-24 | Failed-Detonation Supernovae: Sub-Luminous Low-Velocity Ia Supernovae and Their Kicked Remnant White Dwarfs with Iron-Rich Cores | Type Ia supernovae (SNe Ia) originate from the thermonuclear explosions of
carbon-oxygen (C-O) white dwarfs (WDs). The single-degenerate scenario is a
well-explored model of SNe Ia where unstable thermonuclear burning initiates in
an accreting, Chandrasekhar-mass WD and forms an advancing flame. By several
proposed phy... | 1208.5069v2 |
2012-11-26 | Local Structure and Hyperfine Interactions of 57Fe in NaFeAs Studied by Mossbauer Spectroscopy | Detailed 57Fe Mossbauer spectroscopy measurements on superconducting NaFeAs
powder samples have been performed in the temperature range 13 K < T < 300 K.
The 57Fe spectra recorded in the paramagnetic range (T > TN ~ 46 K) were
discussed supposing that most of the Fe2+ ions are located in distorted (FeAs4)
tetrahedral o... | 1211.5967v3 |
2012-12-02 | Tunable interplay between 3d and 4f electrons in Co-doped iron pnictides | We study the interplay of 3d and 4f electrons in the iron pnictides
CeFe$_{1-x}$Co$_x$AsO and GdFe$_{1-y}$Co$_y$AsO, which correspond to two very
different cases of $4f$-magnetic moment. Both CeFeAsO and GdFeAsO undergo a
spin-density-wave (SDW) transition associated with Fe 3d electrons at high
temperatures, which is ... | 1212.0221v2 |
2013-01-15 | Pulse phase and precession phase resolved spectroscopy of Her X-1: studying a representative Main-On with RXTE | We performed a detailed pulse phase resolved spectroscopy of the accreting
binary X-ray pulsar Her X-1 in the energy range 3.5-75 keV and have established
pulse phase profiles for all spectral parameters. For the centroid of the
cyclotron line, the photon index and the flux of the 6.4 keV iron line, we have
studied the... | 1301.3378v1 |
2013-01-24 | The wind of the M-type AGB star RT Virginis probed by VLTI/MIDI | We study the circumstellar environment of the M-type AGB star RT Vir using
mid-infrared high spatial resolution observations from the ESO-VLTI focal
instrument MIDI. The aim of this study is to provide observational constraints
on theoretical prediction that the winds of M-type AGB objects can be driven by
photon scatt... | 1301.5872v1 |
2013-03-15 | The 69 micron forsterite band in spectra of protoplanetary disks - Results from the Herschel DIGIT programme | Context: We have analysed Herschel-PACS spectra of 32 circumstellar disks
around Herbig Ae/Be and T-Tauri stars obtained within the Herschel key
programme DIGIT. In this paper we focus on the 69mu emission band of the
crystalline silicate forsterite.
Aims: This work provides an overview of the 69mu forsterite bands i... | 1303.3744v1 |
2013-04-30 | Superconductivity induced by hydrogen anion substitution in 1111-type iron arsenides | Hydrogen is the simplest bipolar element and its valence state can be
controlled from +1 to -1. We synthesized the 1111-type CaFeAsH and LnFeAsO1-xHx
(Ln = lanthanide) with the ZrCuSiAs type structure by a high-pressure synthesis
method. The position and valence state of the substituted H were determined by
neutron dif... | 1304.7900v1 |
2013-05-23 | On magnetic inhibition of photospheric macro-turbulence generated in the iron-bump opacity zone of O-stars | Massive, hot OB-stars show clear evidence of strong macroscopic broadening
(in addition to rotation) in their photospheric spectral lines. This paper
examines the occurrence of such "macro-turbulence" in slowly rotating O-stars
with strong, organised surface magnetic fields. Focusing on the CIV 5811A line,
we find evid... | 1305.5549v1 |
2013-06-14 | Dynamic Transcript Profiling of Candida Albicans Infection in Zebrafish: a Pathogen-Host Interaction Study | Candida albicans is responsible for a number of life-threatening infections
and causes considerable morbidity and mortality in immunocompromised patients.
Previous studies of C. albicans pathogenesis have suggested several steps must
occur before virulent infection, including early adhesion, invasion, and late
tissue d... | 1306.3312v1 |
2013-10-09 | Electron doping evolution of the magnetic excitations in BaFe2-xNixAs2 | We use inelastic neutron scattering (INS) spectroscopy to study the magnetic
excitations spectra throughout the Brioullion zone in electron-doped iron
pnictide superconductors BaFe$_{2-x}$Ni$_{x}$As$_{2}$ with $x=0.096,0.15,0.18$.
While the $x=0.096$ sample is near optimal superconductivity with $T_c=20$ K
and has coex... | 1310.2333v1 |
2013-10-11 | The return to the hard state of GX 339-4 as seen by Suzaku | The microquasar GX 339-4 was observed by Suzaku five times, spaced by a few
days, during its transition back to the hard state at the end of its 2010-2011
outburst. The 2-10 keV source flux decreases by a factor ~10 between the
beginning and the end of the monitoring. Simultaneous radio and OIR
observations highlighted... | 1310.3039v2 |
2013-10-30 | On the Origin of the 6.4 keV Line in the Galactic Center Region | We analyse the 6.4 keV iron line component produced in the Galactic Center
(GC) region by cosmic rays in dense molecular clouds (MCs) and in the diffuse
molecular gas. We showed that this component, in principle, can be seen in
several years in the direction of the cloud Srg B2. If this emission is
produced by low ener... | 1310.8177v1 |
2013-11-04 | On the role of AGN feedback on the thermal and chemodynamical properties of the hot intra-cluster medium | We present an analysis of the properties of the ICM in an extended set of
cosmological hydrodynamical simulations of galaxy clusters and groups performed
with the TreePM+SPH GADGET-3 code. Besides a set of non-radiative simulations,
we carried out two sets of simulations including radiative cooling, star
formation, met... | 1311.0818v1 |
2013-11-07 | GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC2 | The inner disk of the Galaxy has a number of young star clusters dominated by
red supergiants that are heavily obscured by dust extinction and observable
only at infrared wavelengths. These clusters are important tracers of the
recent star formation and chemical enrichment history in the inner Galaxy.
During the techni... | 1311.1639v1 |
2013-12-20 | Nematic order in iron superconductors - who is in the driver's seat? | Although the existence of nematic order in iron-based superconductors is now
a well-established experimental fact, its origin remains controversial. Nematic
order breaks the discrete lattice rotational symmetry by making the $x$ and $y$
directions in the Fe plane non-equivalent. This can happen because of (i) a
tetrago... | 1312.6085v1 |
2014-03-24 | On the fine structure of the Cepheid metallicity gradient in the Galactic thin disk | We present homogeneous and accurate iron abundances for 42 Galactic Cepheids
based on high-spectral resolution (R~38,000) high signal-to-noise ratio
(SNR>100) optical spectra collected with UVES at VLT (128 spectra). The above
abundances were complemented with high-quality iron abundances provided either
by our group (... | 1403.6128v1 |
2014-07-03 | The Detection of Earth-mass Planets around Active Stars: The Mass of Kepler-78b | Kepler-78b is a transiting Earth-mass planet in an 8.5 hr orbit discovered by
the Kepler Space Mission. We performed an analysis of the published radial
velocity measurements for Kepler-78 in order to derive a refined measurement
for the planet mass. Kepler-78 is an active star and radial velocity variations
due to act... | 1407.0853v1 |
2014-08-06 | Theory of the evolution of magnetic order in Fe$_{1+y}$Te compounds with increasing interstitial iron | We examine the influence of the excess of interstitial Fe on the magnetic
properties of Fe$_{1+y}$Te compounds. Because in iron chalcogenides the
correlations are stronger than in the iron arsenides, we assume in our model
that some of the Fe orbitals give rise to localized magnetic moments. These
moments interact with... | 1408.1418v2 |
2014-11-28 | Superconducting properties and pseudogap from preformed Cooper pairs in the triclinic (CaFe$_{1-x}$Pt$_x$As)$_{10}$Pt$_3$As$_8$ | Using a combination of muon-spin relaxation ($\mu$SR), inelastic neutron
scattering (INS) and nuclear magnetic resonance (NMR), we investigated the
novel iron-based superconductor with a triclinic crystal structure
(CaFe$_{1-x}$Pt$_x$As)$_{10}$Pt$_3$As$_8$ (T$_{\rm c}$ = 13 K), containing
platinum-arsenide intermediary... | 1411.7858v1 |
2014-12-30 | An XSPEC model to explore spectral features from black-hole sources - II. The relativistic iron line in the lamp-post geometry | In X-ray spectra of several active galactic nuclei and Galactic black hole
binaries a broad relativistically smeared iron line is observed. This feature
arises by fluorescence when the accretion disc is illuminated by hot corona
above it. Due to central location of the corona the illumination and thus also
the line emi... | 1412.8627v1 |
2015-03-14 | Deep SDSS optical spectroscopy of distant halo stars II. Iron, calcium, and magnesium abundances | We analyze a sample of 3,944 low-resolution (R ~ 2000) optical spectra from
the Sloan Digital Sky Survey (SDSS), focusing on stars with effective
temperatures 5800 < Teff < 6300 K, and distances from the Milky Way plane in
excess of 5 kpc, and determine their abundances of Fe, Ca, and Mg. We followed
the same methodolo... | 1503.04362v1 |
2015-05-29 | NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk | We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and
Suzaku observations of the X-ray binary Cygnus X-1 in the hard state. This is
the first time this state has been observed in Cyg X-1 with NuSTAR, which
enables us to study the reflection and broad-band spectra in unprecedented
detail. We confir... | 1506.00007v1 |
2015-06-03 | The complex accretion geometry of GX 339-4 as seen by NuSTAR and Swift | We present spectral analysis of five NuSTAR and Swift observations of GX
339-4 taken during a failed outburst in summer 2013. These observations cover
Eddington luminosity fractions in the range ~0.9-6%. Throughout this outburst,
GX 339-4 stayed in the hard state, and all five observations show similar X-ray
spectra wi... | 1506.01381v1 |
2015-06-05 | NuSTAR and Swift observations of the black hole candidate XTE J1908+094 during its 2013 outburst | The black hole candidate XTE J1908+094 went into outburst for the first time
since 2003 in October 2013. We report on an observation with the Nuclear
Spectroscopic Telescope Array (NuSTAR) and monitoring observations with Swift
during the outburst. NuSTAR caught the source in the soft state: the spectra
show a broad re... | 1506.02001v2 |
2015-07-28 | Probing M subdwarf metallicity with an esdK5+esdM5.5 binary | We present a spectral analysis of the binary G 224-58 AB that consists of the
coolest M extreme subdwarf (esdM5.5) and a brighter primary (esdK5). This
binary may serve as a benchmark for metallicity measurement calibrations and as
a test-bed for atmospheric and evolutionary models for esdM objects.
We determine abun... | 1507.07740v1 |
2015-10-16 | The Transient Accereting X-Ray Pulsar XTE J1946+274: Stability of the X-Ray Properties at Low Flux and Updated Orbital Solution | We present a timing and spectral analysis of the X-ray pulsar XTE J1946+274
observed with Suzaku during an outburst decline in 2010 October and compare
with previous results. XTE J1946+274 is a transient X-ray binary consisting of
a Be-type star and a neutron star with a 15.75 s pulse period in a 172 d orbit
with 2-3 o... | 1510.05032v1 |
2015-11-02 | Electron correlation effects and scattering rates in Fe$_{1+y}$Te$_{1-x}$Se$_x$ superconductor | Using angle-resolved photoemission spectroscopy we have studied the
low-energy electronic structure and the Fermi surface topology of
Fe$_{1+y}$Te$_{1-x}$Se$_x$ superconductors. Similar to the known iron pnictides
we observe hole pockets at the center and electron pockets at the corner of the
Brillouin zone (BZ). Howev... | 1511.00424v1 |
2015-12-03 | Strong anisotropy in nearly ideal-tetrahedral superconducting FeS single crystals | We report the novel preparation of single crystals of tetragonal iron
sulfide, FeS, which exhibits a nearly ideal tetrahedral geometry with S--Fe--S
bond angles of 110.2(2) $^\circ$ and 108.1(2) $^\circ$. Grown via hydrothermal
de-intercalation of K${_x}$Fe${_{2-y}}$S${_2}$ crystals under basic and
reducing conditions,... | 1512.01245v3 |
2016-01-26 | Low-energy Population III supernovae and the origin of extremely metal-poor stars | Some ancient, dim, metal-poor stars may have formed in the ashes of the first
supernovae (SNe). If their chemical abundances can be reconciled with the
elemental yields of specific Population III (Pop III) explosions, they could
reveal the properties of primordial stars. But multidimensional simulations of
such explosi... | 1601.06896v3 |
2016-02-29 | Andreev spectroscopy of iron-based superconductors: temperature dependence of the order parameters and scaling of the $Δ_{L,S}$ with $T_C$ | We studied iron-based superconductors of various families with critical
temperatures covering almost all range $T_C = 9 - 53$ K. In natural arrays of
contacts formed in these materials we observed intrinsic multiple Andreev
reflections effect (IMARE). By using IMARE spectroscopy, we detected the
two-gap superconductivi... | 1602.09114v2 |
2016-03-01 | X-ray-binary spectra in the lamp post model | [Abridged] Context. The high-energy radiation from black-hole binaries may be
due to the reprocessing of a lamp located on the black hole axis, emitting
X-rays. The observed spectrum is made of 3 components: the direct spectrum; the
thermal bump; and the reflected spectrum made of the Compton hump and the
iron-line com... | 1603.00185v2 |
2016-09-15 | Self-consistent mapping: Effect of local environment on formation of magnetic moment in alpha-FeSi2 | We suggest here the method of the mapping of DFT calculations on the
multiorbital model in a following way: the parameters of the formulated
multiorbital model should be determined from the requirement that the
self-consistent charge and spin densities found from the ab initio and model
calculations have to be as close... | 1609.04624v1 |
2016-09-26 | Phase Transition of Iron-based Single Crystals at Extreme Strain Rates under Dynamic Loadings | Phase transition of iron, as a prototype of martensite phase transition under
dynamic loadings, exhibits huge diverges in its TP among experiments with
different pressure medium and loading rates, even in the same initial samples.
Great achievements are made in understanding strain or stress dependence of the
TP under ... | 1609.07829v2 |
2017-01-24 | Nucleosynthesis in the Innermost Ejecta of Neutrino-Drive Supernova Explosions in Two Dimensions | We examine the nucleosynthesis in the innermost, neutrino-processed ejecta (a
few $10^{-3}\,M_\odot$) of self-consistent, two-dimensional explosion models of
core-collapse supernovae for six progenitor stars with different initial
masses. Three models have initial masses near the low-mass end of the supernova
range, $8... | 1701.06786v2 |
2017-04-04 | Competing spin density wave, collinear, and helical magnetism in Fe1+xTe | The Fe1+xTe phase diagram consists of two distinct magnetic structures with
collinear order present at low interstitial iron concentrations and a helical
phase at large values of x with these phases separated by a Lifshitz point. We
use unpolarized single crystal diffraction to confirm the helical phase for
large inter... | 1704.01111v1 |
2017-05-07 | The peculiar Na-O anticorrelation of the bulge globular cluster NGC 6440 | Context. Galactic Globular Clusters (GCs) are essential tools to understand
the earliest epoch of the Milky Way, since they are among the oldest objects in
the Universe and can be used to trace its formation and evolution. Current
studies using high resolution spectroscopy for many stars in each of a large
sample of GC... | 1705.02684v1 |
2017-05-10 | Direct Measurement of Nuclear Dependence of Charged Current Quasielastic-like Neutrino Interactions using MINERvA | Charged-current $\nu_{\mu}$ interactions on carbon, iron, and lead with a
final state hadronic system of one or more protons with zero mesons are used to
investigate the influence of the nuclear environment on quasielastic-like
interactions. The transfered four-momentum squared to the target nucleus,
$Q^2$, is reconstr... | 1705.03791v1 |
2017-05-30 | Chemical Complexity in the Eu-enhanced Monometallic Globular Cluster NGC 5986 | NGC 5986 is a poorly studied but relatively massive Galactic globular cluster
that shares several physical and morphological characteristics with
"iron-complex" clusters known to exhibit significant metallicity and heavy
element dispersions. In order to determine if NGC 5986 joins the iron-complex
cluster class, we inv... | 1705.10840v1 |
2017-07-11 | First results from the IllustrisTNG simulations: A tale of two elements -- chemical evolution of magnesium and europium | The distribution of elements in galaxies provides a wealth of information
about their production sites and their subsequent mixing into the interstellar
medium. Here we investigate the distribution of elements within stars in the
IllustrisTNG simulations. In particular, we analyze the abundance ratios of
magnesium and ... | 1707.03401v2 |
2017-08-20 | Large anomalous Nernst and spin Nernst effects in noncollinear antiferromagnets Mn$_3X$ ($X$ = Sn, Ge, Ga) | Noncollinear antiferromagnets have recently been attracting considerable
interest partly due to recent surprising discoveries of the anomalous Hall
effect (AHE) in them and partly because they have promising applications in
antiferromagnetic spintronics. Here we study the anomalous Nernst effect (ANE),
a phenomenon hav... | 1708.05933v3 |
2017-09-15 | Investigating the interstellar dust through the Fe K-edge | The chemical and physical properties of interstellar dust in the densest
regions of the Galaxy are still not well understood. X-rays provide a powerful
probe since they can penetrate gas and dust over a wide range of column
densities (up to $10^{24}\ \rm{cm}^{-2}$). The interaction (scattering and
absorption) with the ... | 1709.05359v1 |
2017-10-11 | Fermi surface with Dirac fermions in CaFeAsF determined via quantum oscillation measurements | Despite the fact that 1111-type iron arsenides hold the record transition
temperature of iron-based superconductors, their electronic structures have not
been studied much because of the lack of high-quality single crystals. In this
study, we completely determine the Fermi surface in the antiferromagnetic state
of CaFe... | 1710.03938v3 |
2017-10-26 | X-ray reflection from cold white dwarfs in magnetic cataclysmic variables | We model X-ray reflection from white dwarfs (WD) in magnetic cataclysmic
variables (mCVs) with a Monte Carlo simulation. A point source with a power-law
spectrum or a realistic post-shock accretion column (PSAC) source irradiates a
cool and spherical WD. The PSAC source emits thermal spectra of various
temperatures str... | 1710.09931v1 |
2017-12-19 | Magnetic phase diagram of the iron pnictides in the presence of spin-orbit coupling: Frustration between $C_2$ and $C_4$ magnetic phases | We investigate the impact of spin anisotropic interactions, promoted by
spin-orbit coupling, on the magnetic phase diagram of the iron-based
superconductors. Three distinct magnetic phases with Bragg peaks at $(\pi,0)$
and $(0,\pi)$ are possible in these systems: one $C_2$ (i.e. orthorhombic)
symmetric stripe magnetic ... | 1712.07192v4 |
2018-01-03 | Sequential structural and antiferromagnetic transitions in BaFe$_2$Se$_3$ under pressure | The discovery of superconductivity in the two-leg ladder compound
BaFe$_2$S$_3$ has established the 123-type iron chalcogenides as a novel and
interesting subgroup of the iron-based superconductors family. However, in this
123 series, BaFe$_2$Se$_3$ is an exceptional member, with a magnetic order and
crystalline struct... | 1801.00877v1 |
2018-02-12 | Superconducting transition temperatures in the electronic and magnetic phase diagrams of Sr2VFeAsO3-delta, a superconductor | We elucidate the magnetic phases and superconducting transition temperatures
(Tc) in Sr2VFeAsO3-delta (21113V), an iron-based superconductor with a
thick-blocking layer fabricated from a perovskite-related transition metal
oxide. At low temperatures (T < 37.1 K), 21113V exhibited a superconducting
phase in the range 0.... | 1802.03907v2 |
2018-07-20 | Measurement of the Iron Spectrum in Cosmic Rays by VERITAS | We present a new measurement of the energy spectrum of iron nuclei in cosmic
rays from 20 to 500 TeV. The measurement makes use of a template-based analysis
method, which, for the first time, is applied to the energy reconstruction of
iron-induced air showers recorded by the VERITAS array of imaging atmospheric
Cherenk... | 1807.08010v1 |
2018-07-23 | The Quantum Field Of A Magnet Shown By A Nanomagnetic Ferrolens | It has been more than two hundred years since the first iron filings
experiment, showing us the 2D macroscopic magnetic imprint of the field of a
permanent magnet. However, latest developments in modern nanomagnetic passive
direct observation devices reveal in real-time and color a more intriguing 3D
dynamic and detail... | 1807.08751v1 |
2018-10-05 | (16) Psyche: A mesosiderite-like asteroid? | Asteroid (16) Psyche is the target of the NASA Psyche mission. It is
considered one of the few main-belt bodies that could be an exposed
proto-planetary metallic core and that would thus be related to iron
meteorites. Such an association is however challenged by both its near- and
mid-infrared spectral properties and t... | 1810.02771v1 |
2018-11-26 | Confirming the presence of second population stars and the iron discrepancy along the AGB of the globular cluster NGC 6752 | Asymptotic giant branch (AGB) stars in the globular cluster NGC6752 have been
found to exhibit some chemical peculiarities with respect to the red giant
branch (RGB) stars. A discrepancy between [FeI/H] and [FeII/H] (not observed in
RGB stars) has been detected adopting spectroscopic temperatures. Moreover, a
possible ... | 1811.10626v1 |
2019-03-06 | Lattice Disorder Effect on Magnetic Ordering of Iron Arsenides | This study investigates the changes of magnetic ordering temperature via
nano- and mesoscale structural features in an iron arsenide. Although magnetic
ground states in quantum materials can be theoretically predicted from known
crystal structures and chemical compositions, the ordering temperature is
harder to pinpoin... | 1903.02545v2 |
2019-05-24 | How much of the Solar System should we leave as Wilderness? | "How much of the Solar System should we reserve as wilderness, off-limits to
human development?" We argue that, as a matter of policy, development should be
limited to one eighth, with the remainder set aside. We argue that adopting a
"1/8 principle" is far less restrictive, overall, than it might seem. One
eighth of t... | 1905.13681v1 |
2019-07-26 | Stabilization of $\varepsilon$-Fe$_2$O$_3$ epitaxial layer on MgO(111)/GaN via an intermediate $γ$-Fe$_2$O$_3$-phase | In the present study we have demonstrated epitaxial stabilization of the
metastable magnetically-hard $\varepsilon$-Fe$_2$O$_3$ phase on top of a thin
MgO(111) buffer layer grown onto the GaN (0001) surface. The primary purpose to
introduce a 4\,nm-thick buffer layer of MgO in between Fe$_2$O$_3$ and GaN was
to stop th... | 1907.11611v2 |
2019-08-06 | On the use of field RR Lyrae as Galactic probes: I. The Oosterhoff dichotomy based on fundamental variables | We collected a large data set of field RR Lyrae stars (RRLs) by using
catalogues already available in the literature and Gaia DR2. We estimated the
iron abundances for a sub-sample of 2,382 fundamental RRLs ($\Delta$S method:
CaIIK, H$\beta$, H$\gamma$ and H$\delta$ lines) for which are publicly
available medium-resolu... | 1908.02064v2 |
2019-08-27 | Carbon, oxygen, and iron abundances in disk and halo stars. Implications of 3D non-LTE spectral line formation | The abundances of carbon, oxygen, and iron in late-type stars are important
parameters in exoplanetary and stellar physics, as well as key tracers of
stellar populations and Galactic chemical evolution. We carried out
three-dimensional (3D) non-LTE radiative transfer calculations for CI and OI,
and 3D LTE radiative tra... | 1908.10319v2 |
2020-01-03 | The chemical composition of the accretion disk and donor star in Ultra Compact X-ray Binaries: A comprehensive X-ray analysis | We have analyzed the X-ray spectra of all known Ultra Compact X-ray Binaries
(UCXBs), with the purpose of constraining the chemical composition of their
accretion disk and donor star. Our investigation was focused on the presence
(or absence) of the Fe K${\alpha}$ emission line, which was used as the probe
of chemical ... | 2001.00716v2 |
2020-01-20 | The extreme CNO-enhanced composition of the primitive iron-poor dwarf star J0815+4729 | We present an analysis of high-resolution Keck/HIRES spectroscopic
observations of J0815+4729, an extremely carbon-enhanced, iron-poor dwarf star.
These high-quality data allow us to derive a metallicity of
[Fe/H]$=-5.49{\pm}0.14$ from the three strongest \ion{Fe}{1} lines and to
measure a high [Ca/Fe]~$=0.75{\pm}0.14$... | 2001.07257v2 |
2020-01-21 | Observation of magnetic adatom-induced Majorana vortex and its hybridization with field-induced Majorana vortex in an iron-based superconductor | Braiding Majorana zero modes is essential for fault-tolerant topological
quantum computing. Iron-based superconductors with nontrivial band topology
have recently emerged as a surprisingly promising platform for creating
distinct Majorana zero modes in magnetic vortices in a single material and at
relatively high tempe... | 2001.07376v2 |
2020-06-05 | Chandra View of the LINER-type Nucleus in the Radio-Loud Galaxy CGCG 292-057: Ionized Iron Line and Jet-ISM Interactions | We present an analysis of the new, deep (94\,ksec) {\it Chandra} ACIS-S
observation of radio-loud active galaxy CGCG\,292$-$057, characterized by a
LINER-type nucleus and a complex radio structure that indicates intermittent
jet activity. On the scale of the host galaxy bulge, we detected excess X-ray
emission with a s... | 2006.03717v2 |
2020-06-29 | No Redshift Evolution in the Broad Line Region Metallicity up to z=7.54: Deep NIR Spectroscopy of ULAS J1342+0928 | We present deep (9 hours) Gemini-N/GNIRS near-infrared spectroscopic
observations of ULAS J1342+0928, a luminous quasar at z=7.54. Various broad
emission lines were detected, as well as the underlying continuum and iron
forests over the rest-frame wavelength 970-2930A. There is a clear trend that
higher-ionization emis... | 2006.16268v1 |
2020-08-05 | Orbital-selective spin waves in detwinned NaFeAs | The existence of orbital-dependent electronic correlations has been
recognized as an essential ingredient to describe the physics of iron-based
superconductors. NaFeAs, a parent compound of iron based superconductors,
exhibits a tetragonal-to-orthorhombic lattice distortion below $T_s\approx 60$
K, forming an electroni... | 2008.02314v1 |
2020-10-26 | Simulation of hydrogen permeation through pure iron for trapping and surface phenomena characterisation | There is a need for numerical models capable of predicting local accumulation
of hydrogen near stress concentrators and crack tips to prevent and mitigate
hydrogen assisted fracture in steels. The experimental characterisation of
trapping parameters in metals, which is required for an accurate simulation of
hydrogen tr... | 2010.13567v1 |
2020-11-11 | Non-stoichiometric amorphous magnesium-iron silicates in circumstellar dust shells. Dust growth in outflows from supergiants | We investigate the dust growth in oxygen-rich stellar outflows for a set of
nine well-observed massive supergiants with optically thin dust shells. Models
of the infrared emission from their circumstellar dust shells are compared to
their observed infrared spectra so as to derive the essential parameters that
govern du... | 2011.05903v1 |
2020-11-17 | On the Probability that a Rocky Planet's Composition Reflects its Host Star | The bulk density of a planet, as measured by mass and radius, is a result of
planet structure and composition. Relative proportions of iron core, rocky
mantle, and gaseous envelopes are degenerate for a given density. This
degeneracy is reduced for rocky planets without significant gaseous envelopes
when the structure ... | 2011.08893v4 |
2021-01-22 | Spin dynamics in NaFeAs and NaFe$_{0.53}$Cu$_{0.47}$As probed by resonant inelastic X-ray scattering | The parent compounds of iron-based superconductors are magnetically-ordered
bad metals, with superconductivity appearing near a putative magnetic quantum
critical point. The presence of both Hubbard repulsion and Hund's coupling
leads to rich physics in these multiorbital systems, and motivated descriptions
of magnetis... | 2101.08948v1 |
2021-02-17 | Single particle tunneling spectroscopy and superconducting gaps in layered iron based superconductor KCa$_{2}$Fe$_{4}$As$_{4}$F$_{2}$ | We perform scanning tunneling microscopy/spectroscopy study on the layered
iron based superconductor KCa$_2$Fe$_4$As$_4$F$_2$ with a critical temperature
of about 33.5 K. Two types of terminated surfaces are generally observed after
cleaving the samples in vacuum. On one commonly obtained surface, we observe a
full gap... | 2102.08785v1 |
2021-03-11 | Intertwined charge, spin, and pairing orders in doped iron ladders | Motivated by recent experimental progress on iron-based ladder compounds, we
study the doped two-orbital Hubbard model for the two-leg ladder BaFe$_2$S$_3$.
The model is constructed by using {\it ab initio} hopping parameters and the
ground state properties are investigated using the density matrix
renormalization grou... | 2103.06407v2 |
2021-03-11 | Enhancement of Superconductivity Linked with Linear-in-Temperature/Field Resistivity in Ion-Gated FeSe Films | Iron selenide (FeSe) - the structurally simplest iron-based superconductor,
has attracted tremendous interest in the past years. While the transition
temperature (Tc) of bulk FeSe is $\sim$ 8 K, it can be significantly enhanced
to 40 - 50 K by various ways of electron doping. However, the underlying
physics for such gr... | 2103.06512v2 |
2021-06-08 | Atomic iron and nickel in the coma of C/1996 B2 (Hyakutake): production rates, emission mechanisms, and possible parents | Two papers recently reported the detection of gaseous nickel and iron in the
comae of over 20 comets from observations collected over two decades, including
interstellar comet 2I/Borisov. To evaluate the state of the laboratory data in
support of these identifications, we re-analyzed archived spectra of comet
C/1996 B2... | 2106.04701v2 |
2021-09-01 | No umbrella needed: Confronting the hypothesis of iron rain on WASP-76b with post-processed general circulation models | High-resolution spectra are unique indicators of three-dimensional processes
in exoplanetary atmospheres. For instance, in 2020, Ehrenreich et al. reported
transmission spectra from the ESPRESSO spectrograph yielding an anomalously
large Doppler blueshift from the ultra-hot Jupiter WASP-76b. Interpretations of
these ob... | 2109.00163v2 |
2021-10-21 | Heat Capacity of oxide scale in the range from 0 C to 1300 C: Generalized estimates with account for movability of phase transitions | The known data on the heat capacity of magnetite (Fe3O4), hematite (Fe2O3)
and iron (Fe) at different temperatures are approximated by formulas containing
phase transition temperatures as varying parameters. This allows to take into
account the effect of phase transition shifts, for example, due to impurities,
lattice ... | 2110.11101v1 |
2021-11-20 | Gaia-ESO Survey: Detailed elemental abundances in red giants of the peculiar globular cluster NGC 1851 | Context. NGC 1851 is one of several globular clusters for which multiple
stellar populations of the subgiant branch have been clearly identified and a
difference in metallicity detected. A crucial piece of information on the
formation history of this cluster can be provided by the sum of A(C+N+O)
abundances. However, t... | 2111.10684v1 |
2021-12-12 | Top-heavy stellar mass distribution in galactic nuclei inferred from the universally high abundance ratio of [Fe/Mg] | Recent observations of active galactic nuclei (AGNs) have shown a high
Fe~II/Mg~II line-flux ratio in their broad-line regions, nearly independent of
redshift up to $z \gtrsim 6$. The high flux ratio requires rapid production of
iron in galactic nuclei to reach an abundance ratio of ${\rm [Fe/Mg]} \gtrsim
0.2$ as high ... | 2112.06151v1 |
2022-03-16 | Measurements of protons and charged pions emitted from $ν_μ$ charged-current interactions on iron at a mean neutrino energy of 1.49$\,$GeV using a nuclear emulsion detector | This study conducted an analysis of muons, protons, and charged pions emitted
from $\nu_{\mu}$ charged-current interactions on iron using a nuclear emulsion
detector. The emulsion detector with a 65$\,$kg iron target was exposed to a
neutrino beam corresponding to 4.0$\times$10$^{19}$ protons on target with a
mean neut... | 2203.08367v3 |
2022-07-06 | Atomic diffusion and turbulent mixing in solar-like stars: Impact on the fundamental properties of FG-type stars | Chemical composition is an important factor that affects stellar evolution.
The element abundance on the stellar surface evolves along the lifetime of the
star because of transport processes, including atomic diffusion. However,
models of stars with masses higher than about 1.2Msun predict unrealistic
variations at the... | 2207.02779v1 |
2022-07-28 | Symmetry protected 1D chains in mixed-valence iron oxides | During the last decade of high-pressure research a whole new series of iron
oxides was discovered, like Fe$_4$O$_5$, Fe$_5$O$_6$, Fe$_7$O$_9$ etc.,
featuring closely related structures with arrays of one-dimensional (1D) chains
of trigonal prisms embedded between slabs of octahedra. Here, we develop a
unified approach ... | 2207.14111v1 |
2022-08-01 | Sustainable steel through hydrogen plasma reduction of iron ore: process, kinetics, microstructure, chemistry | Fe- and steelmaking is the largest single industrial CO2 emitter, accounting
for 6.5% of all CO2 emissions on the planet. This fact challenges the current
technologies to achieve carbon-lean steel production and to align with the
requirement of a drastic reduction of 80% in all CO2 emissions by around 2050.
Thus, alter... | 2208.00661v1 |
2022-09-27 | 3D non-LTE iron abundances in FG-type dwarfs | Spectroscopic measurements of iron abundances are prone to systematic
modelling errors. We present 3D non-LTE calculations across 32 STAGGER-grid
models with effective temperatures from 5000 K to 6500 K, surface gravities of
4.0 dex and 4.5 dex, and metallicities from $-$3 dex to 0 dex, and study the
effects on 171 Fe ... | 2209.13449v3 |
2022-10-24 | High-precision abundances of first population stars in NGC 2808: confirmation of a metallicity spread | Photometric investigations have revealed that Galactic globular clusters
exhibit internal metallicity variations amongst the so-called first-population
stars, until now considered to have a homogeneous initial chemical composition.
This is not fully supported by the sparse spectroscopic evidence, which so far
gives con... | 2210.13369v1 |
2023-01-07 | Changes in the distribution of circum-binary material around the HMXB GX 301-2 during a rapid spin-up episode of the neutron star | Some accretion powered X-ray pulsars with supergiant companion stars undergo
occasional rapid spin-up episodes that last for weeks to a few months. We
explore the changes in the accretion environment of the pulsar GX 301-2 during
its latest 80 days long spin-up episode in 2019 when the spin frequency of the
pulsar incr... | 2301.02815v1 |
2023-03-09 | Saline bolus for negative contrast perfusion imaging in magnetic particle imaging | Objective. Magnetic Particle Imaging (MPI) is capable of high temporal
resolution measurements of the spatial distribution of magnetic nanoparticles
and therefore well suited for perfusion imaging, which is an important tool in
medical diagnosis. Perfusion imaging in MPI usually requires a fresh bolus of
tracer materia... | 2303.05439v2 |
2023-03-19 | In-situ visualization of local distortions in the high-$T_c$ molecule-intercalated $Li_x(C_5H_5N)_yFe_{2-z}Se_2$ superconductor | A time-resolved synchrotron X-ray total scattering study sheds light on the
evolution of the different structural length scales involved during the
intercalation of the layered iron-selenide host by organic molecular donors,
aiming at the formation of the expanded lattice $Li_x(C_5H_5N)_yFe_{2-z}Se_2$
hybrid supercondu... | 2303.10698v1 |
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