publicationDate stringlengths 1 2.79k | title stringlengths 1 36.5k ⌀ | abstract stringlengths 1 37.3k ⌀ | id stringlengths 9 47 |
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2021-04-20 | Stellar winds and metal enrichment from fast-rotating Population III stars | Stellar winds from fast-rotating Population III (Pop III) stars have long
been suspected to make important contributions to early metal enrichment, as
features in the nucleosynthesis of such `spinstars' are consistent with the
chemical abundance patterns of some metal-poor stars in the local Universe.
Particularly, ste... | 2104.10046v2 |
2021-05-06 | The Iron Yield of Normal Type II Supernovae | We present $^{56}$Ni mass estimates for 110 normal Type II supernovae (SNe
II), computed here from their luminosity in the radioactive tail. This sample
consists of SNe from the literature, with at least three photometric
measurements in a single optical band within 95-320 d since explosion. To
convert apparent magnitu... | 2105.03268v1 |
2021-06-24 | Time-resolved diffraction and photoelectron spectroscopy investigation of the reactive molecular beam epitaxy of $\mathrm{Fe_3O_4}$ ultrathin films | We present time-resolved high energy x-ray diffraction (tr-HEXRD),
time-resolved hard x-ray photoelectron spectroscopy (tr-HAXPES) and
time-resolved grazing incidence small angle x-ray scattering (tr-GISAXS) data
of the reactive molecular beam epitaxy (RMBE) of $\mathrm{Fe_3O_4}$ ultrathin
films on various substrates. ... | 2106.13192v1 |
2021-10-15 | Type Ia Supernova Models: Asymmetric Remnants and Supernova Remnant G1.9+0.3 | The youngest Galactic supernova remnant G1.9+0.3, probably the result of a
Type Ia supernova, shows surprising anomalies in the distribution of its ejecta
in space and velocity. In particular, high-velocity shocked iron is seen in
several locations far from the remnant center, in some cases beyond prominent
silicon and... | 2110.08360v1 |
2021-10-28 | Non-homogeneous exoplanets in metric-affine gravity | The improved description of the planets' interior is provided. We examine the
modified gravity effects on the Earth-like planets composed of the iron core
and silicate mantle. We confirm that the mass-radius relations, as well as
density profiles, differ with respect to the commonly adopted Newtonian models. | 2110.15139v2 |
2021-12-03 | The 1966 International Congress of Mathematicians: A micro-memoir | To an extent, the 1966 congress was a hole in the iron curtain. At least that
how a young Soviet mathematician saw it. | 2112.04900v4 |
2022-03-21 | Accurate Determination of the Electron Spin Polarization In Magnetized Iron and Nickel Foils for Møller Polarimetry | The M{\o}ller polarimeter in Hall A at Jefferson Lab in Newport News, VA, has
provided reliable measurements of electron beam polarization for the past two
decades reaching the typically required $\pm$1\% level of absolute uncertainty.
However, the upcoming proposed experimental program including MOLLER and SoLID
have ... | 2203.11238v2 |
2022-04-19 | Characterizing the Advective Hot Flows of Nova-Like Cataclysmic Variables in the X-rays: The case of BZ Cam and V592 Cas | We present a joint spectral analysis of ROSAT PSPC, Swift XRT, and NuSTAR
FPMA/B data of the nova-like (NL) cataclysmic variables (CVs), BZ Cam and V592
Cas in the 0.1-78.0 keV band. Plasma models of collisional equilibrium fail to
model the 6.0-7.0 iron line complex and continuum with $\chi^2_\nu$ larger than
2.0. Our... | 2204.08842v1 |
2022-05-04 | On Internal and External Alignment of Dust Grains in Protostellar Environments | We study the physical processes inducing the alignment of the grain axis of
maximum inertia moment with the angular momentum (${\bf J}$, i.e., internal
alignment) and of ${\bf J}$ with the magnetic field (i.e., external alignment)
of very large grains (VLGs, of radius $a>10\mu$m) using the grain alignment
framework bas... | 2205.02334v2 |
2022-05-18 | Internet Performance in the 2022 Conflict in Ukraine: An Asymmetric Analysis | On 24 February 2022 Russia invaded Ukraine, starting one of the largest
military conflicts in Europe in recent years. In this paper we present
preliminary findings about the impact of the conflict on the Internet
performance in Ukraine and in Russia, introducing an ironically asymmetric
picture: the Internet performanc... | 2205.08912v1 |
2022-07-12 | Investigating a predicted metallicity [Fe/H] variation in the Type II Globular Cluster NGC 362 | NGC 362 is a non-common Type II Galactic globular cluster, showing a complex
pseudo two-color diagram or 'chromosome map'. The clear separation of its
stellar populations in the color-magnitude diagram and the distribution of the
giant stars in the chromosome map strongly suggests that NGC 362 could host
stars with bot... | 2207.05693v1 |
2022-09-12 | The Iron Yield of Core-collapse Supernovae | We present a systematic analysis of 191 stripped-envelope supernovae (SE
SNe), aimed to compute their $^{56}$Ni masses from the luminosity in their
radioactive tails ($M_\mathrm{Ni}^\mathrm{tail}$) and/or in their maximum
light, and the mean $^{56}$Ni and iron yields of SE SNe and core-collapse SNe.
Our sample consists... | 2209.05552v2 |
2023-02-08 | A portable and high intensity 24 keV neutron source based on $^{124}$Sb-$^{9}$Be photoneutrons and an iron filter | A portable monoenergetic 24 keV neutron source based on the $^{124}$Sb-$^9$Be
photoneutron reaction and an iron filter has been constructed and
characterized. The coincidence of the neutron energy from SbBe and the low
interaction cross-section with iron (mean free path up to 29 cm) makes pure
iron specially suited to ... | 2302.03869v1 |
2023-04-17 | A structural study of hcp and liquid iron under shock compression up to 275 GPa | We combine nanosecond laser shock compression with \emph{in-situ} picosecond
X-ray diffraction to provide structural data on iron up to 275 GPa. We
constrain the extent of hcp-liquid coexistence, the onset of total melt, and
the structure within the liquid phase. Our results indicate that iron, under
shock compression,... | 2304.07933v3 |
2023-05-08 | First evidence of multi-iron sub-populations in the Bulge Fossil Fragment candidate Liller 1 | In the context of a project aimed at characterizing the properties of the
so-called Bulge Fossil Fragments (the fossil remnants of the bulge formation
epoch), here we present the first determination of the metallicity distribution
of Liller 1. For a sample of 64 individual member stars we used ESO- MUSE
spectra to meas... | 2305.04595v1 |
2023-05-13 | mechanical properties of CaFe2As2 ab-initio study | We report results on the ab-initio study of the mechanical, electronic and
structural properties of the iron Pnictide compound CaFe_2 As_2 at zero
pressure. Ground State energy computation was done within the Density
Functional Theory (DFT) using the Projector Augmented Wave (PAW) Pseudo
Potentials and the Plane Wave (... | 2305.07949v1 |
2023-06-28 | Preliminary Tc calculations for iron-based superconductivity in NaFeAs, LiFeAs, FeSe and nanostructured FeSe/SrTiO3 Superconductors | Many theoretical models of iron-based superconductors have been proposed but
Tc calculations based on the models are usually missing. We have chosen two
models of iron-based superconductors in the literature and then compute the Tc
values accordingly: Recently two models have been announced which suggest that
supercond... | 2306.15892v1 |
2023-10-14 | Order-disorder phase transition and elastic-to-plastic vortex creep crossover in a triclinic iron pnictide superconductor (Ca0.85La0.15)10(Pt3As8)(Fe2As2)5 | Vortex matter in layered high-$T_c$ superconductors, including
iron-pnictides, undergo several thermodynamic phase transitions due to the
complex interplay of pinning energy, thermal energy and elastic energy.
Moreover, the presence of anisotropy makes their vortex physics even more
intriguing. Here, we report a detail... | 2310.09557v1 |
2024-03-05 | Spatially resolving the AGB star V3 in the metal-poor globular cluster 47 Tuc with VLTI/GRAVITY | Mass loss at the asymptotic giant branch (AGB) plays an important role not
only in the final fates of stars, but also in the chemical evolution of
galaxies. Nevertheless, the metallicity effects on AGB mass loss are not yet
fully understood. We present spatially resolved observations of an AGB star,
V3, in the metal-po... | 2403.03287v2 |
2003-11-12 | Heavy elements abundances in turn-off stars and early subgiants in NGC 6752 | High resolution spectra (R > 40 000) for 9 main sequence turn-off stars and 9
subgiants in the globular cluster NGC 6752 were acquired with UVES on the
VLT-Kueyen (UT2). These data have been used to determine the abundances of some
heavy elements (strontium, yttrium, barium and europium). This paper presents
for the fi... | 0311278v1 |
2008-02-22 | A comparison of the s- and r-process element evolution in local dwarf spheroidal galaxies and in the Milky Way | We study the nucleosynthesis of several neutron capture elements (barium,
europium, lanthanum, and yttrium) in local group dwarf spheroidal (dSph)
galaxies and in the Milky Way by comparing the evolution of [Ba/Fe], [Eu/Fe],
[La/Fe], [Y/Fe], [Ba/Y], [Ba/Eu], [Y/Eu], and [La/Eu] observed in dSph galaxies
and in our Gala... | 0802.3368v1 |
2008-08-29 | Mass measurements in the vicinity of the rp-process and the nu p-process paths with JYFLTRAP and SHIPTRAP | The masses of very neutron-deficient nuclides close to the astrophysical rp-
and nu p-process paths have been determined with the Penning trap facilities
JYFLTRAP at JYFL/Jyv\"askyl\"a and SHIPTRAP at GSI/Darmstadt. Isotopes from
yttrium (Z = 39) to palladium (Z = 46) have been produced in heavy-ion
fusion-evaporation ... | 0808.4065v1 |
2009-10-05 | The Hamburg/ESO R-process Enhanced Star survey (HERES) IV. Detailed abundance analysis and age dating of the strongly r-process enhanced stars CS 29491-069 and HE 1219-0312 | We report on a detailed abundance analysis of two strongly r-process
enhanced, very metal-poor stars newly discovered in the HERES project, CS
29491-069 ([Fe/H]=-2.51, [r/Fe]=+1.1) and HE 1219-0312 ([Fe/H]=-2.96,
[r/Fe]=+1.5). The analysis is based on high-quality VLT/UVES spectra and MARCS
model atmospheres. We detect... | 0910.0707v1 |
2009-11-23 | A Two Micron All-Sky Survey View of the Sagittarius Dwarf Galaxy: VI. s-Process and Titanium Abundance Variations Along the Sagittarius Stream | We present high-resolution spectroscopic measurements of the abundances of
titanium (Ti), yttrium (Y) and lanthanum (La) for M giant candidates of the
Sagittarius (Sgr) dwarf spheroidal (dSph) + tidal tail system pre-selected on
the basis of position and radial velocity. The majority of these stars show
peculiar abunda... | 0911.4364v1 |
2010-09-22 | The Ubiquity of the Rapid Neutron-Capture Process | To better characterize the abundance patterns produced by the r-process, we
have derived new abundances or upper limits for the heavy elements zinc (Zn),
yttrium (Y), lanthanum (La), europium (Eu), and lead (Pb). Our sample of 161
metal-poor stars includes new measurements from 88 high resolution and high
signal-to-noi... | 1009.4496v1 |
2012-05-28 | The Chemical composition of the post-AGB F-supergiant CRL 2688 | We present an analysis of a high resolution (R~50,000) optical spectrum of
the central region of the proto-planetary nebula CRL 2688. This object is
thought to have recently moved off the AGB, and display abundance patterns of
CNO and heavy elements that can provide us with important clues to understand
the nucleosynth... | 1205.6101v4 |
2013-03-28 | Non-monotonic residual entropy in diluted spin ice: a comparison between Monte Carlo simulations of diluted dipolar spin ice models and experimental results | Spin ice materials, such as Dy2Ti2O7 and Ho2Ti2O7, have been the subject of
much interest for over the past fifteen years. Their low temperature strongly
correlated state can be mapped onto the proton disordered state of common water
ice and, consequently, spin ices display the same low temperature residual
Pauling ent... | 1303.7240v1 |
2015-07-21 | Testing and Performance of UFFO Burst Alert & Trigger Telescope | The Ultra-Fast Flash Observatory pathfinder (UFFO-p) is a new space mission
dedicated to detect Gamma-Ray Bursts (GRBs) and rapidly follow their afterglows
in order to provide early optical/ultraviolet measurements. A GRB location is
determined in a few seconds by the UFFO Burst Alert & Trigger telescope (UBAT)
employi... | 1507.05696v1 |
2016-11-16 | Spectral hole lifetimes and spin population relaxation dynamics in neodymium-doped yttrium orthosilicate | We present a detailed study of the lifetime of optical spectral holes due to
population storage in Zeeman sublevels of Nd$^{3+}$:Y$_2$SiO$_5$. The lifetime
is measured as a function of magnetic field strength and orientation,
temperature and Nd$^{3+}$ doping concentration. At the lowest temperature of 3
K we find a gen... | 1611.05444v1 |
2017-06-20 | Abundance analysis of a CEMP-no star in the Carina dwarf spheroidal galaxy | Carbon-enhanced metal-poor (CEMP) stars bear important imprints of the early
chemical enrichment of any stellar system. While these stars are known to exist
in copious amounts in the Milky Way halo, detailed chemical abundance data from
the faint dwarf spheroidal (dSph) satellites are still sparse, although the
relativ... | 1706.06599v1 |
2018-02-22 | Super-Solar Metallicity Stars in the Galactic Center Nuclear Star Cluster: Unusual Sc, V, and Y Abundances | We present adaptive-optics assisted near-infrared high-spectral resolution
observations of late-type giants in the nuclear star cluster of the Milky Way.
The metallicity and elemental abundance measurements of these stars offer us an
opportunity to understand the formation and evolution of the nuclear star
cluster. In ... | 1802.08270v2 |
2019-11-01 | Which oxidation state of uranium and thorium as point defects in xenotime is favorable? | Relativistic study of xenotime, YPO$_4$, containing atoms thorium and uranium
as point defects is performed in the framework of cluster model with using the
compound-tunable embedding potential (CTEP) method proposed by us recently. The
Y-(PO$_4$)$_6$-Y'$_{22}$-O'$_{104}$ cluster for xenotime is considered, in
which ce... | 1911.00365v3 |
2020-07-17 | Crystalline and magnetic structures, magnetization, heat capacity and anisotropic magnetostriction effect in a yttrium-chromium oxide | We have studied a nearly stoichiometric insulating
Y$_{0.97(2)}$Cr$_{0.98(2)}$O$_{3.00(2)}$ single crystal by performing
measurements of magnetization, heat capacity, and neutron diffraction. Albeit
that the YCrO$_3$ compound behaviors like a soft ferromagnet with a coersive
force of $\sim$ 0.05 T, there exist strong a... | 2007.08985v2 |
2020-10-01 | Yttrium-90 TOF-PET based EUD predicts response post liver radioembolizations using standard manufacturer reconstruction parameters | Purpose: Explaining why 90Y TOF-PET based equivalent uniform dose (EUD) using
standard FDG reconstruction parameters has been shown to predict response.
Methods: The hot rods insert of a Jaszczak deluxe phantom was partially
filled with a 2.65 GBq 90Y - 300ml DTPA water solution resulting in a 100 Gy
mean absorbed do... | 2010.00303v1 |
2021-04-13 | Selectivity in yttrium manganese oxide synthesis via local chemical potentials in hyperdimensional phase space | In sharp contrast to molecular synthesis, materials synthesis is generally
presumed to lack selectivity. The few known methods of designing selectivity in
solid-state reactions have limited scope, such as topotactic reactions or
strain stabilization. This contribution describes a general approach for
searching large ch... | 2104.05986v3 |
2021-07-12 | The systematic study on the stability and superconductivity of Y-Mg-H compounds under high pressure | Motivated by recent discovery of yttrium-based high-temperature ternary
superconducting hydrides (e.g., CaYH$_{12}$, LaYH$_{12}$, and ScYH$_{6}$), we
have employed evolutionary algorithm and first-principles calculations to
comprehensively examine the structural stability and superconductivity of the
YMgH$_{x}$ system ... | 2107.05498v2 |
2021-10-27 | Orbital and atmospheric parameters of two wide O-type subdwarf binaries: BD$-$11$^{\rm{o}}$162 and Feige 80 | There are 23 long-period binary systems discovered to date that contain a
B-type hot subdwarf(sdB) whose orbital parameters have been fully solved. They
evolve into O-type subdwarfs (sdO) once the helium burning transitions from the
core to the He shell. Their study will help constraint parameters on the
formation and ... | 2110.14339v1 |
2021-10-29 | Sr-Doped Molecular Hydrogen: Synthesis and Properties of SrH$_{22}$ | Recently, several research groups announced reaching the point of
metallization of hydrogen above 400 GPa. Following the mainstream of extensive
investigations of compressed polyhydrides, in this work we demonstrate that
small (4 atom %) doping of molecular hydrogen by strontium leads to a dramatic
reduction in the met... | 2110.15628v2 |
2021-12-04 | Hole- and electron-injection driven phase transitions in transition metal dichalcogenides and beyond: A unified understanding | The phase transitions among polymorphic two-dimensional (2D) transition metal
dichalcogenides (TMDs) have attracted increasing attention for their potential
in enabling distinct functionalities in the same material for making integrated
devices. Electron-injection to TMDs has been proved to be a feasible way to
drive s... | 2112.02319v1 |
2022-05-30 | Comparative characterization study of LYSO:Ce crystals for timing applications | Cerium-doped Lutetium-Yttrium Oxyorthosilicate (LYSO:Ce)is one of the most
widely used Cerium-doped Lutetium based scintillation crystals. Initially
developed for medical detectors it rapidly became attractive for High Energy
Particle Physics (HEP) applications, especially in the frame of high luminosity
particle colli... | 2205.14890v2 |
2022-06-21 | Is [Y/Mg] a Reliable Age Diagnostic for FGK Stars? | Current spectroscopic surveys are producing large catalogs of chemical
abundances for stars of all types. The yttrium to magnesium ratio, [Y/Mg], has
emerged as a candidate age indicator for solar twins in the local stellar
neighborhood. However, it is unclear whether it is a viable age diagnostic for
more diverse stel... | 2206.10624v2 |
2022-09-14 | Spectroscopic r-Process Abundance Retrieval for Kilonovae I: The Inferred Abundance Pattern of Early Emission from GW170817 | Freshly-synthesized r-process elements in kilonovae ejecta imprint absorption
features on optical spectra, as observed in the GW170817 binary neutron star
merger. These spectral features encode insights into the physical conditions of
the r-process and the origins of the ejected material, but associating features
with ... | 2209.06951v2 |
2022-11-23 | Evidence for centrosymmetry breaking and multiferroic properties in the A-site ordered quadruple perovskite YMn$_3$Mn$_4$O$_{12}$ | By means of single-crystal X-ray diffraction we have revealed the breaking of
centrosymmetry when lowering the temperature under T$_s$ = 200 K concomitantly
with the setting of a commensurate superstructure in the small A-site quadruple
perovskite YMn$_3$Mn$_4$O$_{12}$. This results is in agreement with all data
alread... | 2211.13037v1 |
2023-04-24 | Development of an eReaxFF Force Field for BZY20 Solid Oxide Electrocatalysis | Electrocatalysis is a catalytic process where the rate of an electrochemical
reaction occurring at the electrode-electrolyte interface can be controlled by
varying the electrical potential. Electrocatalysis can be applied to generate
hydrogen which can be stored for future use in fuel cells for clean
electricity. The u... | 2304.14256v1 |
2023-07-20 | Decoding the compositions of four bright $r$-process-enhanced stars | There has been a concerted effort in recent years to identify the
astrophysical sites of the $r$-process that can operate early in the Galaxy.
The discovery of many $r$-process-enhanced (RPE) stars (especially by the
$R$-process Alliance collaboration) has significantly accelerated this effort.
However, only limited da... | 2307.10762v1 |
2023-08-11 | NEMA NU 2-2018 performance evaluation of a new generation digital 32-cm axial field-of-view Omni Legend PET-CT | A NEMA performance evaluation was conducted on the new General Electric (GE)
digital Omni Legend PET-CT system with 32-cm extended field-of-view. This study
marks the introduction of the first-ever commercially available clinical
digital bismuth germanate technology. Testing was performed in accordance with
the NEMA NU... | 2308.06255v1 |
2023-08-23 | Observational constraints on the origin of the elements. VII. NLTE analysis of Y II lines in spectra of cool stars and implications for Y as a Galactic chemical clock | Yttrium (Y), a key s-process element, is commonly used in nucleosynthesis
studies and as a Galactic chemical clock when combined with magnesium (Mg). We
study the applicability of the previously assumed LTE line formation assumption
in Y abundance studies of main-sequence and red giant stars, and probe the
impact of NL... | 2308.12092v1 |
2023-11-09 | Observational constraints on the origin of the elements. VIII. Constraining the Barium, Strontium and Yttrium chemical evolution in metal-poor stars | Recently Lian et al. (2023), thanks to Gaia-ESO data, studied the chemical
evolution of neutron-capture elements in the regime [Fe/H]>-1. We aim here to
complement this study down to [Fe/H]=-3, and focus on Ba, Y, Sr, and abundance
ratios of [Ba/Y] and [Sr/Y], which give comprehensive views on s-process
nucleosynthesis... | 2311.05459v1 |
2024-02-26 | Disorder-induced local strain distribution in Y-substituted TmVO4 | We report an investigation of the effect of substitution of Y for Tm in
$Tm_{1-x}Y_xVO4$ via low-temperature heat capacity measurements, with the
yttrium content $x$ varying from $0$ to $0.997$. Because the Tm ions support a
local quadrupolar (nematic) moment, they act as reporters of the local strain
state in the mate... | 2402.17049v1 |
1999-06-03 | Transition to Long Range Magnetic Order in the Highly Frustrated Insulating Pyrochlore Antiferromagnet Gd_2Ti_2O_7 | Experimental evidence from measurements of the a.c. and d.c. susceptibility,
and heat capacity data show that the pyrochlore structure oxide, Gd_2Ti_2O_7,
exhibits short range order that starts developing at 30K, as well as long range
magnetic order at $T\sim 1$K. The Curie-Weiss temperature, $\theta_{CW}$ =
-9.6K, is ... | 9906043v1 |
2015-05-09 | Solutions of the Two Dimensional Hubbard Model: Benchmarks and Results from a Wide Range of Numerical Algorithms | Numerical results for ground state and excited state properties (energies,
double occupancies, and Matsubara-axis self energies) of the single-orbital
Hubbard model on a two-dimensional square lattice are presented, in order to
provide an assessment of our ability to compute accurate results in the
thermodynamic limit.... | 1505.02290v2 |
2017-03-14 | Spin-projected matrix product states (SP-MPS): a versatile tool for strongly correlated systems | We present a new wavefunction ansatz that combines the strengths of spin
projection with the language of matrix product states (MPS) and matrix product
operators (MPO) as used in the density matrix renormalization group (DMRG).
Specifically, spin-projected matrix product states (SP-MPS) are constructed as
$|\Psi^{(N,S,... | 1703.04789v3 |
2018-07-17 | Ce-doped Gd${}_{3}$Al${}_{2}$Ga${}_{3}$O${}_{12}$ scintillator for compact, effective and high time resolution detector of the fast neutrons | Gadolinium-aluminum-gallium garnet
Gd${}_{3}$Al${}_{2}$Ga${}_{3}$O${}_{12}$:Ce scintillator is demonstrated to be
an excellent scintillation material for detector of fast neutrons for the first
time. Moreover, its application allows to obtain different responses to
neutrons depending on their energy spectrum. This is a... | 1807.06390v1 |
2019-03-21 | Quantitative magneto-optical imaging with ferrite garnets | Magneto-optical imaging is a powerful technique for studying qualitative
features of magnetic flux distributions in superconductors and other magnetic
samples. However, magneto-optical imaging does not automatically return
two-dimensional maps with the actual values of the magnetic field, due to the
non-linear response... | 1903.09130v1 |
2019-07-21 | A Compton polarimeter using scintillators read out with MPPCs through Citiroc ASIC | In recent years, a number of purpose-built scintillator-based polarimeters
have studied bright astronomical sources for the first time in the hard X-ray
band (tens to hundreds of keV). The addition of polarimetry can help data
interpretation by resolving model-dependent degeneracies. The typical
instrument approach is ... | 1907.09030v1 |
2020-01-14 | Ground-state phase diagram of the three-band Hubbard model from density matrix embedding theory | We determine the ground-state phase diagram of the three-band Hubbard model
across a range of model parameters using density matrix embedding theory. We
study the atomic-scale nature of the antiferromagnetic (AFM) and
superconducting (SC) orders, explicitly including the oxygen degrees of
freedom. All parametrizations ... | 2001.04951v4 |
2020-02-28 | Recent developments in the PySCF program package | PYSCF is a Python-based general-purpose electronic structure platform that
both supports first-principles simulations of molecules and solids, as well as
accelerates the development of new methodology and complex computational
workflows. The present paper explains the design and philosophy behind PYSCF
that enables it ... | 2002.12531v2 |
2020-05-21 | Emergent magnetic behaviour in the frustrated Yb$_3$Ga$_5$O$_{12}$ garnet | We report neutron scattering, magnetic susceptibility and Monte Carlo
theoretical analysis to verify the short range nature of the magnetic structure
and spin-spin correlations in a Yb$_3$Ga$_5$O$_{12}$ single crystal. The
quantum spin state of Yb$^{3+}$ in Yb$_3$Ga$_5$O$_{12}$ is verified. The
quantum spins organise i... | 2005.10605v5 |
2020-08-06 | The Ground State Electronic Energy of Benzene | We report on the findings of a blind challenge devoted to determining the
frozen-core, full configuration interaction (FCI) ground state energy of the
benzene molecule in a standard correlation-consistent basis set of
double-$\zeta$ quality. As a broad international endeavour, our suite of wave
function-based correlati... | 2008.02678v2 |
2020-08-26 | Waveguide integrated high performance magneto-optical isolators and circulators on silicon nitride platforms | Optical isolators and circulators are indispensable for photonic integrated
circuits (PICs). Despite of significant progress in silicon-on-insulator (SOI)
platforms, integrated optical isolators and circulators have been rarely
reported on silicon nitride (SiN) platforms. In this paper, we report
monolithic integration... | 2010.01969v1 |
2021-01-08 | A summary on an investigation of GAGG:Ce afterglow emission in the context of future space applications within the HERMES nanosatellite mission | GAGG:Ce (Cerium-doped Gadolinium Aluminium Gallium Garnet) is a promising new
scintillator crystal. A wide array of interesting features, such as high light
output, fast decay times, almost non-existent intrinsic background and
robustness, make GAGG:Ce an interesting candidate as a component of new
space-based gamma-ra... | 2101.03945v1 |
2022-03-29 | Doping effect and Li-ion conduction mechanism of ALi6XO6 (A = K or Rb, and X = pentavalent): A first-principles study | Recent theoretical and experimental evaluations demonstrated that KLi6TaO6 is
a good Li-ion conductor. In this study, the energetics and detailed mechanism
of Li-ion migration, relevant to the point defects of KLi6TaO6, were analyzed
by first-principles calculations. Defect formation energy analysis suggested
that it h... | 2203.15384v4 |
2022-08-10 | CLARION2-TRINITY: a Compton-suppressed HPGe and GAGG:Ce-Si-Si array for absolute cross-section measurements with heavy ions | The design and performance of a new Compton-suppressed HPGe and
charged-particle array, CLARION2-TRINITY, are described. The TRINITY
charged-particle array is comprised of 64 Cerium-doped Gadolinium Aluminium
Gallium Garnet (GAGG:Ce) crystals configured into five rings spanning 7-54
degrees, and two annular silicon det... | 2208.05449v1 |
2022-11-16 | Interacting models for twisted bilayer graphene: a quantum chemistry approach | The nature of correlated states in twisted bilayer graphene (TBG) at the
magic angle has received intense attention in recent years. We present a
numerical study of an interacting Bistritzer-MacDonald (IBM) model of TBG using
a suite of methods in quantum chemistry, including Hartree-Fock, coupled
cluster singles, doub... | 2211.09243v1 |
2023-03-15 | Chiral phonons and phononic birefringence in ferromagnetic metal - bulk acoustic resonator hybrids | Magnomechanical devices, in which magnetic excitations couple to mechanical
vibrations, have been discussed as efficient and broadband microwave signal
transducers in the classical and quantum limit. We experimentally investigate
the magnetoelastic coupling between the ferromagnetic resonance (FMR) modes in
a metallic ... | 2303.08429v1 |
1994-12-01 | A Determination of the Thick Disk Chemical Abundance Distribution: Implications for Galaxy Evolution | We present a determination of the thick disk iron abundance distribution
obtained from an in situ sample of F/G stars. These stars are faint, $15 \simlt
V \simlt 18$, selected on the basis of color, being a subset of the larger
survey of Gilmore and Wyse designed to determine the properties of the stellar
populations s... | 9411116v1 |
1995-05-23 | Bimodal star formation in elliptical galaxies and the enrichment of the intra-cluster medium | A detailed model of galactic evolution is proposed to explain both the iron
content of the Intra-Cluster Medium (ICM) and of the ellipticals pertaining to
the cluster. SNII are responsible for the production of Fe in the galaxies and
of its partial ejection in the surrounding medium. A high formation rate of
massive st... | 9505107v2 |
1995-06-07 | Good Abundances from Bad Spectra :II. Application and a New Stellar Color--Temperature Relation | Stellar spectra derived from current multiple-object fiber-fed spectroscopic
radial-velocity surveys, of the type feasible with, among other examples,
AUTOFIB, 2dF, HYDRA, NESSIE, and the Sloan survey, differ significantly from
those traditionally used for determination of stellar abundances. The spectra
tend to be of ... | 9506044v1 |
1995-07-15 | On broad iron K-alpha lines in Seyfert 1 galaxies | The X-ray spectrum obtained by Tanaka et al from a long observation of the
active galaxy MCG$-6-30-15$ shows a broad iron K$\alpha$ line skewed to low
energies. The simplest interpretation of the shape of the line is that it is
due to doppler and gravitational redshifts from the inner parts of a disk about
a massive bl... | 9507061v1 |
1996-01-25 | Non-LTE Treatment of Fe II in Astrophysical Plasmas | We describe our implementation of an extremely detailed model atom of singly
ionized iron for NLTE computations in static and moving astrophysical plasmas.
Our model atom includes 617 levels, 13675 primary permitted transitions and up
to 1.2 million secondary transitions. Our approach guarantees that the total
iron opa... | 9601148v1 |
1996-03-17 | Dormant dwarf spheroidal galaxies, deactivated by Type Ia supernovae | Some dwarf spheroidal galaxies have experienced many Gyrs long periods
without star formation. We show that Type Ia supernovae, formed from a first
generation of stars, can delay a second epoch of star formation by several
Gyrs, if the total gas mass in the dwarf spheroidals is smaller than $10^8
M_{\odot}$. The detail... | 9603089v1 |
1996-05-19 | Multiphase Chemical Evolution in Elliptical Galaxies | The recent {\em ASCA} results show that the iron abundance of the X-ray gas
of elliptical galaxies is less than the solar abundance ($Z_{\sun}$). The
observed low iron abundance is inconsistent with the predictions of the
previous chemical evolution models. In order to solve this problem, we present
a simple model of c... | 9605115v1 |
1996-10-23 | Magnetized Iron Atmospheres for Neutron Stars | Using a Hartree-Fock formalism, we estimate energy levels and photon cross
sections for atomic iron in magnetic fields B ~ 10^13 G. Computing ionization
equilibrium and normal mode opacities with these data, we construct LTE neutron
star model atmospheres at 5.5 < Log(T_eff) < 6.5 and compute emergent spectra.
We exami... | 9610177v2 |
1997-04-17 | The profile and equivalent width of the X-ray iron emission-line from a disk around a Kerr black hole | Recent X-ray observations have shown broad, skewed iron line emission from
Seyfert 1 galaxies which is explained by the emission being fluorescence on a
disk close to a black hole. During one interval, the line in MCG--6-30-15 was
so broad and redshifted that a Kerr black hole is implied. We are therefore
studying the ... | 9704177v1 |
1997-08-04 | On the dependence of the iron K-line profiles with luminosity in Active Galactic Nuclei | We present evidence for changes in the strength and profile of the iron
K-alpha line in Active Galactic Nuclei (AGN), based on X-ray observations with
ASCA. There is a clear decrease in the strength of the line with increasing
luminosity. This relation is is not due solely to radio power, as it persists
when only radio... | 9708030v1 |
1997-12-15 | BeppoSAX observations of Narrow-Line Seyfert 1 galaxies:I. Ton S 180 | We report on the first spectrum up to 10 keV of the bright narrow-line
Seyfert 1 galaxy Ton S 180, obtained with the imaging instruments onboard
BeppoSAX. This is the first observed source in a sample of a dozen narrow-line
Seyfert 1 galaxies in the BeppoSAX Core Program. We also present and discuss a
high quality opti... | 9712182v1 |
1998-04-18 | Lyman Alpha Fluorescent Excitation of FeII in Active Galactic Nuclei | We have calculated FeII emission line strengths for Active Galactic Nuclei
Broad-Line Regions using precise radiative transfer and Iron Project atomic
data. We improve the treatment of all previously considered excitation
mechanisms for the FeII emission, continuum fluorescence, collisional
excitation, fluorescence by ... | 9804183v1 |
1998-05-15 | ASCA Observation of the polar RX J1802.1+1804 | We present X-ray data of RX J1802.1+1804 obtained by ASCA. Although it shows
a clear orbital intensity modulation with an amplitude of nearly 100% below 0.5
keV in ROSAT data, the ASCA light curves are nearly flat except for a possible
dip lasting about one-tenth of the orbital period. We discuss this within the
model ... | 9805211v1 |
1998-10-05 | New Insights into the Early Stage of the Galactic Chemical Evolution | The supernova yields of several heavy elements including alpha-, iron-group,
and r-process elements are obtained as a function of the mass of their
progenitor main-sequence stars M_ms from the abundance patterns of extremely
metal-poor stars with a procedure recently proposed by Shigeyama and Tsujimoto
(1998). The ejec... | 9810056v1 |
1998-11-13 | Detection of Iron Emission Line from the Galaxy Cluster Including the Distant Radio Galaxy 3C220.1 | We detected an emission line feature at 4 keV in the X-ray spectrum of a sky
region including the distant radio galaxy 3C220.1(z=0.62) obtained with ASCA.
The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of 3C220.1.
Within the present statistics, the observed spectra are consistent with two
different... | 9811212v2 |
1999-01-07 | Comparisons of various model fits to the Iron line profile in MCG-6-30-15 | The broad Iron line in MCG-6-30-15 is fitted to the Comptonization model
where line broadening occurs due to Compton down-scattering in a highly ionized
optically thick cloud. These results are compared to the disk line model where
the broadening is due to Gravitational/Doppler effects in the vicinity of a
black hole. ... | 9901065v1 |
1999-03-12 | On the nature of the X-ray source 1E 1024.0--5732/Wack 2134 | Two different models have been put forward to explain the origin of the X-ray
emission of the unusual X-ray source 1E 1024.0-5732/Wack 2134: a high-mass
X-ray binary system (HMXB) and a colliding wind binary (CWB). We present new
optical and X-ray data in an attempt to clarify the nature of this system. The
data seem t... | 9903197v1 |
1999-04-07 | Variation of the broad X-ray iron line in MCG-6-30-15 during a flare | We report results on the broad iron emission line of the Seyfert galaxy
MCG-6-30-15, obtained from the second long ASCA observation in 1997. The
time-averaged profile of the broad line is very similar to that seen with ASCA
in 1994, so confirming the detailed model fit then obtained. A bright flare is
seen in the light... | 9904078v1 |
1999-04-27 | Physical Parameters of Hot Horizontal-Branch Stars in NGC 6752: Deep Mixing and Radiative Levitation | Atmospheric parameters (Teff, log g and log(He/H)) are derived for 42 hot
horizontal branch (HB) stars in the globular cluster NGC 6752. For 19 stars
MgII and FeII lines are detected indicating an iron enrichment by a factor 50
on average with respect to the cluster abundance whereas the magnesium
abundances are consis... | 9904377v1 |
1999-05-20 | Metal Enrichment in the Early Galactic Halo | An early history of metal enrichment in the Galactic halo is studied. We
investigate chemical inhomogeneity by using a stochastic chemical evolution
model. The model confronts with metallicity distribution function of long-lived
halo stars which is found to be a clue to obtain the best model prescriptions.
We find that... | 9905260v2 |
1999-06-11 | Frequency resolved spectroscopy of Cyg X-1: fast variability of the Fe K_alpha line | We studied the frequency resolved energy spectra of Cyg X--1 during the
standard low (hard) spectral state using the data of the Rossi X-Ray Timing
Explorer. We found that the relative amplitude of the reflection features --
the iron fluorescent line at ~6.5 keV and the smeared edge above ~7 keV --
decreases with the i... | 9906198v1 |
1999-06-17 | On the anomalous X-ray afterglows of GRB 970508 and GRB 970828 | Recently, BeppoSAX and ASCA have reported an unusual resurgence of soft X-ray
emission during the afterglows of GRB 970508 and GRB 970828, together with
marginal evidence for the existence of Fe-lines in both objects. We consider
the implications of the existence of a torus of iron-rich material surrounding
the sites o... | 9906288v1 |
1999-08-17 | Detection of Iron Emission Line from the Galaxy Cluster Including the Radio Galaxy 3C220.1 at z=0.62 | We have detected an emission line feature at 4 keV in the X-ray emission from
a sky region including the distant radio galaxy 3C220.1(z=0.62) obtained with
ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of
3C220.1. Within the present statistics, the observed spectra are consistent
with two di... | 9908178v1 |
1999-12-07 | On the inability of Comptonization to produce the broad X-ray iron lines observed in Seyfert nuclei | It has recently been suggested that Compton downscattering may give rise to
the broad iron lines seen in the X-ray spectra of Seyfert 1 galaxies. This
challenges the standard model in which these lines originate from the innermost
regions of the black hole accretion disk with Doppler shifts and gravitational
redshifts ... | 9912120v2 |
1999-12-08 | A two zone model for the broad Iron line emission in MCG-6-30-15 | We reanalyze the ASCA and BeppoSAX data of MCG-6-30-15, using a double zone
model for the Iron line profile. In this model, the X-ray source is located
around $\approx 10$ Schwarzschild radius and the regions interior and exterior
to the X-ray source produce the line emission. We find that this model fits the
data with... | 9912178v1 |
2000-01-26 | Growth of a Vortex Mode during Gravitational Collapse Resulting in Type II Supernova | We investigate stability of a gravitationally collapsing iron core against
non-spherical perturbation. The gravitationally collapsing iron core is
approximated by a similarity solution for dynamically collapsing polytropic gas
sphere. We find that the similarity solution is unstable against non-spherical
perturbations.... | 0001447v1 |
2000-03-30 | Discovery of a new pulsating X-ray source with a 1549.1-s period, AX J183220-0840 | A new pulsating X-ray source, AX J183220-0840, with a 1549.1-s period was
discovered at R.A.= 18h32m20s and Dec.=-8d40'30'' (J2000,
uncertainty=0.6degree) during an ASCA observation on the Galactic plane. The
source was observed two times, in 1997 and in 1999. A phase-averaged X-ray flux
of 1.1E-11 ergs cm-2 s-1 and pu... | 0003448v1 |
2000-05-30 | BeppoSAX Observations of Bright Radio Galaxies | BeppoSAX observations of Broad Line Radio Galaxies (BLRGs) have shown that
they have a considerable variety of spectral properties and important
differences with respect to their radio-quiet counter-part Seyfert 1s. In radio
galaxies the soft photons are often absorbed by cold material. In contrast, in
Seyfert 1s the s... | 0005577v1 |
2000-06-01 | Possible Evidence for a Truncated Thin Disk in Seyfert 1 Galaxy NGC4593 | We compile the multi-band spectral energy distribution (SED) of Seyfert 1
galaxy NGC4593, and investigate its optical-to-ultraviolet (OUV) continuum and
iron K\alpha line profile. No strong ``big blue bump'' is found in OUV band.
The iron K\alpha line profile is not as broad as expected from a disk which
extends down t... | 0006004v1 |
2000-06-14 | A cloud model of active galactic nuclei: the iron K-alpha line diagnostics | The origin and the profile of the iron K-alpha line from active galactic
nuclei is being studied. The model with a quasi-spherical distribution of
clouds around a compact galactic nucleus is explored in which the intrinsic
spectral feature around 6-7 keV is substantially affected by Comptonization of
primary X-rays. Th... | 0006187v1 |
2000-07-26 | New constraints from Haverah Park data on the photon and iron fluxes of UHE cosmic rays | Using data from inclined events ($60^{\circ}<\theta<80^{\circ}$) recorded by
the Haverah Park shower detector, we show that above 10^19 eV less than 30% of
the primary cosmic rays can be photons or iron nuclei at the 95% confidence
level. Above 4 10^19 eV less than 55% of the cosmic rays can be photonic at the
same con... | 0007386v2 |
2000-08-09 | Detection of a broad iron emission line and sub-millisecond quasiperiodic oscillations from the type I X-ray burster 4U1728-34 in a high state | We report results from simultaneous RossiXTE and BeppoSAX observations of the
neutron-star x-ray binary and type I X-ray burster 4U1728-34. The source was
found in a high luminosity state, L_X near 0.1 L_Edd, and quasiperiodic
oscillations were detected at 1284 +/- 6 Hz, the highest frequency ever
observed from this so... | 0008141v1 |
2000-08-15 | RXTE observations of the Seyfert galaxy NGC 5506: evidence for reflection from disk and torus | We report on observations of the narrow line Seyfert galaxy NGC 5506 with the
Rossi X-ray TIming Explorer. The observations cover a time interval of ~1000
days during which the source showed strong flux and spectral variability. The
spectrum clearly shows iron fluorescence emission at 6.4 keV and significant
reflection... | 0008219v1 |
2000-09-06 | Evolution of the X-ray luminosity and metallicity of starburst blown superbubbles | We calculate the time-dependent metal production expected from starbursts and
use them as boundary conditions in our 2D simulations of evolving superbubbles.
We assume that the produced metals (oxygen and iron) thoroughly mix with the
ejected stellar envelopes, and/or with the matter thermally evaporated from the
super... | 0009092v1 |
2000-09-15 | Iron Abundance Profiles of 12 Clusters of Galaxies Observed With BeppoSAX | We have derived azimuthally-averaged radial iron abundance profiles of the
X-ray gas contained within 12 clusters of galaxies with redshift 0.03 < z < 0.2
observed with BeppoSAX. We find evidence for a negative metal abundance
gradient in most of the clusters, particularly significant in clusters that
possess cooling f... | 0009237v1 |
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