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2020-05-13
Neutron spin resonance in a quasi-two-dimensional iron-based superconductor
Magnetically mediated Cooper pairing is generally regarded as a key to establish the unified mechanism of unconventional superconductivity. One crucial evidence is the neutron spin resonance arising in the superconducting state, which is commonly interpreted as a spin-exciton from collective particle-hole excitations c...
2005.06146v1
2020-05-19
Speciation of FeS and FeS$_2$ by means of X-ray Emission Spectroscopy using a compact full-cylinder von Hamos spectrometer
We present Fe K$\beta$ X-ray emission (XES) and Fe K X-ray absorption spectra (XAS) of Iron(II)sulfide (FeS) and Iron(II)disulfide (FeS$_2$). While XES and XAS offer different discrimination capabilities for chemical speciation, depending on the valence states of the compounds probed, XES allows for using different exc...
2005.09509v1
2020-05-19
Hydrostatic and uniaxial pressure tuning of iron-based superconductors: Insights into superconductivity, magnetism, nematicity and collapsed tetragonal transitions
Iron-based superconductors are well-known for their intriguing phase diagrams, which manifest a complex interplay of electronic, magnetic and structural degrees of freedom. Among the phase transitions observed are superconducting, magnetic, and several types of structural transitions, including a tetragonal-to-orthorho...
2005.09791v1
2020-06-29
Nematic Fluctuations in an Orbital Selective Superconductor Fe$_{1+y}$Te$_{1-x}$Se$_{x}$
We present a systematic study of the nematic fluctuations in the iron chalcogenide superconductor Fe$_{1+y}$Te$_{1-x}$Se$_{x}$ ($0 \leq x \leq 0.53$) using the elastoresistivity technique. Near $x = 0$, in proximity to the double-stripe magnetic order of Fe$_{1+y}$Te, a diverging $B_{1g}$ nematic susceptibility is obse...
2006.15887v1
2020-07-19
Anomalous spectral weight transfer in the nematic state of iron-selenide superconductor
Nematic phase intertwines closely with high-Tc superconductivity in iron-based superconductors. Its mechanism, which is closely related to the pairing mechanism of superconductivity, still remains controversial. Comprehensive characterization of how the electronic state reconstructs in the nematic phase is thus crucial...
2007.09565v1
2020-07-20
Vortex-line topology in iron-based superconductors with and without second-order topology
The band topology of a superconductor is known to have profound impact on the existence of Majorana zero modes in vortices. As iron-based superconductors with band inversion and $s_{\pm}$-wave pairing can give rise to time-reversal invariant second-order topological superconductivity, manifested by the presence of heli...
2007.10326v4
2020-08-05
Black Dwarf Supernova in the Far Future
In the far future long after star formation has ceased the universe will be populated by sparse degenerate remnants, mostly white dwarfs, though their ultimate fate is an open question. These white dwarfs will cool and freeze solid into black dwarfs while pycnonuclear fusion will slowly process their composition to iro...
2008.02296v1
2020-08-18
Returning radiation in strong gravity around black holes: Reverberation from the accretion disc
We study reflected X-ray emission that returns to the accretion disc in the strong gravitational fields around black holes using General Relativistic ray tracing and radiative transfer calculations. Reflected X-rays that are produced when the inner regions of the disc are illuminated by the corona are subject to strong...
2008.08083v1
2021-02-09
Reinforcing Iron Metal Matrix Composite by Multi-Wall Carbon Nanotube: A Combined Theoretical and Computational Approach
Carbon nanotube (CNT) reinforced metal matrix composites have been the focus of researchers due to their high load-bearing capacity. Among single and multi-wall carbon nanotubes (MWCNT), the latter is preferred by manufacturers and engineers for making composites due to their economic feasibility of synthesizing. Howev...
2102.05025v1
2021-04-07
Fundamental mechanism of the creation of chemical bimodality in the Milky Way disc in the cold accretion theory
Chemical bimodality of the Milky Way (MW) disc stars constitutes one of the most remarkable properties of MW. The cold accretion theory for the cosmological gas accretion provides one viable explanation to this phenomenon. In this scenario, the rapid cold-mode accretion in the early epoch creates the first generation s...
2104.02976v1
2021-05-10
Quantum magnetism of iron-based ladders: Blocks, spirals, and spin flux
Motivated by increasing experimental evidence of exotic magnetism in low-dimensional iron-based materials, we present a comprehensive theoretical analysis of magnetic states of the multiorbital Hubbard ladder in the orbital-selective Mott phase (OSMP). The model we used is relevant for iron-based compounds of the AFe$_...
2105.04391v2
2021-05-14
Spectral and timing properties of the black hole candidate X1755-338 observed in 1989-1995
We report results of an analysis of the black hole (BH) candidate source X1755-338 in 1989, 1990, and 1991 with Ginga, and in 1995 with ASCA. The spectra were well represented by a model consisting of a soft thermal emission from an accretion disk and a hard X-ray tail. The normalization of the multi-color disk model, ...
2105.06628v1
2021-05-20
The Abundance of Lead in Four Metal-Poor Stars
Cowan et al. (2021) review how roughly half the elements heavier than iron found in the Sun are produced by rapid neutron capture and half by slow neutron capture, the r- and s-processes. In the Sun, their relative contribution to individual elemental abundances is well understood, except for the lightest and heaviest ...
2105.09456v1
2021-07-07
Correlations of r-Process Elements in Very Metal-Poor Stars as Clues to their Nucleosynthesis Sites
Various nucleosynthesis studies have pointed out that the r-process elements in very metal-poor (VMP) halo stars might have different origins. By means of familiar concepts from statistics (correlations, cluster analysis, rank tests of elemental abundances), we look for causally correlated elemental abundance patterns ...
2107.03486v1
2021-07-08
Magnetic properties of 3d, 4d, and 5d transition-metal atomic monolayers in Fe/TM/Fe sandwiches: Systematic first-principles study
Previous studies have accurately determined the effect of transition metal point defects on the properties of bcc iron. The magnetic properties of transition metal monolayers on the iron surfaces have been studied equally intensively. In this work, we investigated the magnetic properties of the 3d, 4d, and 5d transitio...
2107.03768v1
2021-07-09
Three-Dimensional Hydrodynamic Simulations of Convective Nuclear Burning In Massive Stars Near Iron Core Collapse
Non-spherical structure in massive stars at the point of iron core collapse can have a qualitative impact on the properties of the ensuing core-collapse supernova explosions and the multi-messenger signals they produce. Strong perturbations can aid successful explosions by strengthening turbulence in the post-shock reg...
2107.04617v1
2021-08-10
Site-selective magnetic moment collapse in compressed Fe5O6
Iron oxide is one of the most important components in Earth's mantle. Recent discovery of the stable presence of Fe5O6 at Earth's mantle environment stimulates significant interests in the understanding of this new category of iron oxides. In this paper, we report the electronic structure and magnetic properties of Fe5...
2108.04473v1
2021-09-08
A new set of chisels for Galactic archaeology: Sc, V and Zn as taggers of accreted globular clusters
Chemical tagging is a powerful tool to reveal the origin of stars and globular clusters (GCs), especially when dynamics alone cannot provide robust answers. So far, mostly $\alpha$- and neutron capture elements have been used to distinguish stars born in the Milky Way (MW) from those born in external environments such ...
2109.03837v1
2021-09-22
Coupling between Antiferromagnetic and Spin Glass Orders in the Quasi-One-Dimensional Iron Telluride TaFe$_{1+x}$Te$_3$ ($x$=0.25)
Understanding the interplay among different magnetic exchange interactions and its physical consequences, especially in the presence of itinerant electrons and disorders, remains one of the central themes in condensed matter physics. In this vein, the coupling between antiferromagnetic and spin glass orders may lead to...
2109.10740v1
2021-09-22
Intermediate spin state and the B1-B2 transition in ferropericlase at tera-Pascal pressures
Ferropericlase (fp), (Mg$_{1-x}$Fe$_x$)O, the second most abundant mineral in the Earth's lower mantle, is expected to be an essential component of super-Earths' mantles. Here we present an ab initio investigation of the structure and magnetic ground state of fp up to $\sim$ 3 TPa with iron concentrations (x$_{Fe}$) va...
2109.11008v2
2021-09-26
Superconducting gap and pseudogap in the surface states of the iron-based superconductor PrFeAsO$_{1-y}$ studied by angle-resolved photoemission spectroscopy
In order to study the possible superconductivity at the polar surfaces of 1111-type iron-based superconductors, which is doped with a large amount of holes in spite of the electron doping in bulk materials, we have performed angle-resolved photoemission spectroscopy (ARPES) studies on superconducting PrFeAsO$_{1-y}$~cr...
2109.12522v2
2021-09-28
Atomistic Graph Neural Networks for metals: Application to bcc iron
The prediction of the atomistic structure and properties of crystals including defects based on ab-initio accurate simulations is essential for unraveling the nano-scale mechanisms that control the micromechanical and macroscopic behaviour of metals. Density functional theory (DFT) can enable the quantum-accurate predi...
2109.14012v1
2021-09-30
Atomistic simulation of the FEBID-driven growth of iron-based nanostructures
The growth of iron-containing nanostructures in the process of focused electron beam-induced deposition (FEBID) of Fe(CO)$_5$ is studied by means of atomistic irradiation-driven molecular dynamics (IDMD) simulations. The geometrical characteristics (lateral size, height and volume), morphology and metal content of the ...
2109.15191v2
2021-10-06
Novel Model of an Ultra-stripped Supernova Progenitor of a Double Neutron Star
Recent discoveries of double neutron star (DNS) mergers and ultra-stripped supernovae (SNe) raise the questions of their origin and connection. We present the first 1D~model of a DNS progenitor system which is calculated self-consistently until an ultra-stripped iron core collapse. We apply the \texttt{MESA} code start...
2110.02979v1
2021-10-11
Dispersionless orbital excitations in (Li,Fe)OHFeSe superconductors
The superconducting critical temperature $T_{\mathrm{c}}$ of intercalated iron-selenide superconductor (Li,Fe)OHFeSe (FeSe11111) can be increased to 42 K from 8 K of bulk FeSe. It shows remarkably similar electronic properties as the high-$T_{\mathrm{c}}$ monolayer FeSe and provides a bulk counterpart to investigate th...
2110.05361v2
2021-10-21
Competing Vortex Topologies in Iron-based Superconductors
In this work, we establish a new theoretical paradigm for vortex Majorana physics in the recently discovered topological iron-based superconductors (tFeSCs). While tFeSCs are widely accepted as an exemplar of topological insulators (TIs) with intrinsic $s$-wave superconductivity, our theory implies that such common bel...
2110.11357v2
2021-11-17
Exoplanetary Interiors
The first mass-estimate of an exoplanet around a Sun-like star, 51 Peg b and the first radius measurement of an exoplanet, HD209458b pointed to the challenges of understanding the atmosphere, interior, and evolution of exoplanets including the possibility of mass loss of planets on close-orbits that are exposed to stro...
2111.09357v1
2022-01-07
Correlation-Driven Electronic Reconstruction in FeTe$_{1-x}$Se$_x$
Electronic correlation is of fundamental importance to high temperature superconductivity. While the low energy electronic states in cuprates are dominantly affected by correlation effects across the phase diagram, observation of correlation-driven changes in fermiology amongst the iron-based superconductors remains ra...
2201.02667v1
2022-02-24
Preferred Spin Excitations in the Bilayer Iron-Based Superconductor CaK(Fe$_{0.96}$Ni$_{0.04}$)$_4$As$_4$ with Spin-Vortex Crystal Order
The spin-orbit coupling (SOC) is a key to understand the magnetically driven superconductivity in iron-based superconductors, where both local and itinerant electrons are present and the orbital angular momentum is not completely quenched. Here, we report a neutron scattering study on the bilayer compound CaK(Fe$_{0.96...
2202.11933v1
2022-04-05
ConfPred: A layered intergrowth structure prediction model based on confinement self-assembly in two-dimensional interlayer space
We constructed a simple but effective model to predict the layered intergrowth structures by combining the self-assembly phenomenon in confined space and the sandwich configuration of layered materials. In this model, a two-dimensional confined space is constructed by two known block layers, such as the Fe$_2$As$_2$ bl...
2204.02355v1
2022-04-11
Polarimetry of M-type asteroids in the context of their surface composition
Aims. We aim to investigate how polarimetric observations can improve our understanding of the nature and diversity of M/X-type asteroids. Methods. Polarimetric observations of the selected M/X-type asteroids were carried out at the Tohoku 0.6-m telescope at Haleakala Observatory, Hawaii (simultaneously in BVR filters)...
2204.04929v1
2022-04-20
Long Term X-Ray Spectral Variation of the Wolf-Rayet Binary WR 102-1 in the Galactic bulge: evidence for wind distortion in the binary
WR~102-1 was detected by Suzaku as a conspicuous point source in the 6.7 keV intensity map of the central region of the Milky Way. The source was suggested as a possible Wolf-Rayet binary based on its X-ray and infrared spectral characteristics. The iron line emission is expected to originate in the Wolf-Rayet star's d...
2204.09349v1
2022-06-20
Prevalence of short-lived radioactive isotopes across exoplanetary systems inferred from polluted white dwarfs
In the Solar System short-lived radioisotopes, such as 26Al, played a crucial role during the formation planetary bodies by providing a significant additional source of heat. Notably, this led to early and large-scale melting and iron core formation in planetesimals and their loss of volatile elements, such as hydrogen...
2206.09675v1
2022-06-30
Magnetic field measurements on the mini-ICAL detector using Hall probes
The magnetised 51 kton Iron Calorimeter (ICAL) detector proposed to be built at INO is designed with a focus on detecting 1-20 GeV muons. The magnetic field will enable the measurement of the momentum of the $\mu^-$ and $\mu^+$ generated from the charge current interactions of $\nu_\mu$ and $\bar\nu_\mu$ separately wit...
2206.15082v1
2022-07-01
Particle acceleration and radiation reaction in a strongly magnetized rotating dipole
Abridged. Neutron stars are surrounded by ultra-relativistic particles efficiently accelerated by ultra strong electromagnetic fields. However so far, no numerical simulations were able to handle such extreme regimes of very high Lorentz factors and magnetic field strengths. It is the purpose of this paper to study par...
2207.00624v1
2022-08-10
Dimensionality and Background Cancellation in Energy Selective X-Ray Imaging
Purpose: The set of linear attenuation coefficients that belong to materials in the human body is commonly assumed to be spanned by two basis functions in the range of clinical x-ray energies, even though there is evidence that the dimensionality of this set is greater than two. It has not yet been clear that the use o...
2208.05362v1
2022-08-11
Atomistic fracture in bcc iron revealed by active learning of Gaussian approximation potential
The prediction of atomistic fracture mechanisms in body-centred cubic (bcc) iron is essential for understanding its semi-brittle nature. Existing atomistic simulations of the crack-tip deformation mechanisms under mode-I loading based on classical interatomic potentials yield contradicting predictions. To enable fractu...
2208.05912v2
2022-08-12
Thermal Evolution and magnetic history of rocky planets
We present a thermal evolution model coupled with a Henyey solver to study the circumstances under which a rocky planet could potentially host a dynamo in its liquid iron core and/or magma ocean. We calculate the evolution of planet thermal profiles by solving the energy balance equations for both the mantle and the co...
2208.06523v1
2022-09-10
Discovery of a pair density wave state in a monolayer high-Tc iron-based superconductor
The pair density wave (PDW) is an extraordinary superconducting state where Cooper pairs carry nonzero momentum. It can emerge when the full condensation of zero momentum Cooper pairs is frustrated. Evidence for the existence of intrinsic PDW order in high-temperature (high-Tc) cuprate superconductors and kagome superc...
2209.04592v2
2022-09-16
Spin fluctuations in the 112-type iron-based superconductor Ca$_{0.82}$La$_{0.18}$Fe$_{0.96}$Ni$_{0.04}$As$_{2}$
We report time-of-flight inelastic neutron scattering (INS) investigations on the spin fluctuation spectrum in the 112-type iron-based superconductor (FeSC) Ca$_{0.82}$La$_{0.18}$Fe$_{0.96}$Ni$_{0.04}$As$_{2}$ (CaLa-112). In comparison to the 122-type FeSCs with a centrosymmetric tetragonal lattice structure (space gro...
2209.07726v1
2022-10-04
Strengthened proximity effect at grain boundaries to enhance inter-grain supercurrent in Ba1-xKxFe2As2 superconductors
Iron-based superconductors have great potential for high-power applications due to their prominent high-field properties. One of the central issues in enhancing the critical current density of iron-based superconducting wires is to reveal the roles and limitations of grain boundaries in supercurrent transport. Here, we...
2210.01305v1
2022-10-18
In-plane electronic anisotropy revealed by interlayer resistivity measurements on the iron-based superconductor parent compound CaFeAsF
Both cuprates and iron-based superconductors demonstrate nematicity, defined as the spontaneous breaking of rotational symmetry in electron systems. The nematic state can play a role in the high-transition-temperature superconductivity of these compounds. However, the microscopic mechanism responsible for the transport...
2210.09533v2
2022-10-19
X-ray spectroscopy of the accretion disk corona source 2S 0921-630 with Suzaku archival data
2S 0921$-$630 is an eclipsing low-mass X-ray binary (LMXB) with an orbital period of $\sim$ 9 days. Past X-ray observations have revealed that 2S 0921$-$630 has an extended accretion disk corona (ADC), from which most of the X-rays from the system are emitted. We report the result of our Suzaku archival data analysis o...
2210.10792v1
2022-11-02
Fourier Disentangled Multimodal Prior Knowledge Fusion for Red Nucleus Segmentation in Brain MRI
Early and accurate diagnosis of parkinsonian syndromes is critical to provide appropriate care to patients and for inclusion in therapeutic trials. The red nucleus is a structure of the midbrain that plays an important role in these disorders. It can be visualized using iron-sensitive magnetic resonance imaging (MRI) s...
2211.01353v1
2022-12-05
Quasi two-dimensional nature of high-Tc superconductivity in iron-based (Li,Fe)OHFeSe
The intercalated iron selenide (Li,Fe)OHFeSe has a strongly layered structure analogous to the quasi two-dimensional (2D) bismuth cuprate superconductors, and exhibits both high-temperature (Tc) and topological superconductivity. However, the issue of its superconductivity dimensionality has not yet been fully investig...
2212.02022v1
2022-12-19
Exchange interactions in iron and nickel: DFT+DMFT study in paramagnetic phase
We analyze possible ways to calculate magnetic exchange interactions within the density functional theory plus dynamical mean-field theory (DFT+DMFT) approach in the paramagnetic phase. Using the susceptibilities obtained within the ladder DMFT approach together with the random phase approximation result for the Heisen...
2212.09267v2
2023-02-08
Microstructure-dependent magnetic properties of iron silicon single, bi- and oligo-crystals measured with a miniaturised Single-Sheet-Tester
Electrical iron silicon steel is the most commonly used soft magnetic material in electrical energy conversion and transmission, and its demand is expected to increase with the need for electrification of the transportation sector and the transition to renewable energy to combat climate change. Although iron silicon st...
2302.03808v1
2023-02-08
Plant-wide byproduct gas distribution under uncertainty in iron and steel industry via quantile forecasting and robust optimization
In the modern iron and steel industry, the efficient distribution of byproduct gases faces significant challenges due to quantity- and quality-related uncertainties of gases. This study presents an optimal approach to gas distribution that addresses this issue by incorporating the energy flow network and the uncertain ...
2302.03946v2
2023-02-28
Spectroscopic studies of the superconducting gap in the 12442 family of iron-based compounds
The iron-based compounds of the so-called 12442 family are very peculiar in various respects. They originate from the intergrowth of 122 and 1111 building blocks, display a large in-plane vs. out-of-plane anisotropy, possess double layers of FeAs separated by insulating layers, and are generally very similar to double-...
2302.14767v2
2023-03-08
Proximity effect and inverse proximity effect in a topological-insulator/iron-based-superconductor heterostructure
We theoretically study the proximity effect and the inverse proximity effect in a topological insulator/iron-based superconductor heterostructure based on the microscopic model. The superconducting order parameter is self-consistently calculated. Its magnitude decreases when the coupling of these two systems increases....
2303.04586v1
2023-03-16
Nucleosynthesis in neutrino-heated ejecta and neutrino-driven winds of core-collapse supernovae; neutrino-induced nucleosynthesis
The innermost ejecta of core-collapse supernovae are considered to be the sources of some iron-group and heavier nuclei. The ejecta are predominantly driven by neutrino heating, principally due to neutrino capture on free neutrons and protons. Such neutrino interaction plays a crucial role for setting neutron richness ...
2303.09442v1
2023-03-28
Iron-rich Metal-poor Stars and the Astrophysics of Thermonuclear Events Observationally Classified as Type Ia Supernovae. I. Establishing the Connection
The progenitor systems and explosion mechanisms responsible for the thermonuclear events observationally classified as Type Ia supernovae are uncertain and difficult to uniquely constrain using traditional observations of Type Ia supernova host galaxies, progenitors, light curves, and remnants. For the subset of thermo...
2303.16357v1
2023-04-11
Orbital Selective Mott Transition Effects and Non-Trivial Topology of Iron Chalcogenide
The iron-based superconductor FeSe$_{1-x}$Te$_{x}$ (FST) has recently gained significant attention as a host of two distinct physical phenomena: ($i$) Majorana zero modes which can serve as potential topologically protected qubits, and ($ii$) a realization of the orbital selective Mott transition (OSMT). In this Letter...
2304.05002v2
2023-04-12
Charge order driven by multiple-Q spin fluctuations in heavily electron-doped iron selenide superconductors
Intertwined spin and charge orders have been widely studied in high-temperature superconductors, since their fluctuations may facilitate electron pairing; however, they are rarely identified in heavily electron-doped iron selenides. Here, using scanning tunneling microscopy, we show that when the superconductivity of (...
2304.05854v1
2023-04-22
A Multi-frequency Magnetic Particle Spectroscopy System for the Characterization of Magnetic Nanoparticles
Magnetic particle spectroscopy (MPS) is one of the most versatile methods to characterize the magnetic properties of magnetic nanoparticles (MNPs). The excitation magnetic field is one of the most crucial factors that affects the MPS signal of the MNPs. In this study, a multi-frequency MPS system is developed to invest...
2304.11290v1
2023-05-10
The spin measurement of MAXI J0637-430: a black hole candidate with high disk density
The Galactic black hole candidate MAXI J0637-430 was first discovered by $\textit{MAXI/GSC}$ on 2019 November 02. We study the spectral properties of MAXI J0637-430 by using the archived $\textit{NuSTAR}$ data and $\textit{Swift}$/XRT data. After fitting the eight spectra by using a disk component and a powerlaw compon...
2305.05914v1
2023-07-20
Stray magnetic field imaging of thin exfoliated iron halides flakes
Magnetic van der Waals materials are often proposed for use in future spintronic devices, aiming to leverage the combination of long-range magnetic order and near-atomic thinness to produce energy-efficient components. One class of material that has been discussed in this context are the iron halides FeCl$_2$ and FeBr$...
2307.10561v1
2023-07-20
Tuning superconductivity and spin-vortex fluctuations in CaKFe$_4$As$_4$ through in-plane antisymmetric strains
Lattice strains of appropriate symmetry have served as an excellent tool to explore the interaction of superconductivity in the iron-based superconductors with nematic and stripe spin-density wave (SSDW) order, which are both closely tied to an orthorhombic distortion. In this work, we contribute to a broader understan...
2307.10604v1
2023-09-07
The impact of rare events on the chemical enrichment in dwarf galaxies
In the environments where the abundance of heavy elements is low, rare events are expected to impact the chemical enrichment. Dwarf galaxies have small masses, low average metallicities and in general low star formation rates, and thus investigating the chemical enrichment provides understanding on the impact of each s...
2309.03795v1
2023-09-29
Fossil and present-day stromatolite ooids contain a meteoritic polymer of glycine and iron
Hemoglycin, a space polymer of glycine and iron, has been identified in the carbonaceous chondritic meteorites Allende, Acfer 086, Kaba, Sutters Mill and Orgueil. Its core form has a mass of 1494Da and is basically an antiparallel pair of polyglycine strands linked at each end by an iron atom. The polymer forms two- an...
2309.17195v2
2023-10-17
Dealing with broad-band X-ray spectra of faint AGN: a case study
In this work we analyse 3 average-luminosity hard X-ray selected AGN: ESO 506-G27, IGR J19039+3344 and NGC 7465. They have simultaneous Swift/XRT and NuSTAR data never published before and have been poorly studied at X-ray energies. These sources make for interesting targets both from a methodological and scientific po...
2310.11319v1
2023-11-04
On the likely magnesium-iron silicate dusty tails of catastrophically evaporating rocky planets
Catastrophically evaporating rocky planets provide a unique opportunity to study the composition of small planets. The surface composition of these planets can be constrained via modelling their comet-like tails of dust. In this work, we present a new self-consistent model of the dusty tails: we physically model the tr...
2311.02477v2
2023-11-24
Layer-dependent superconductivity in iron-based superconductors
The Hohenberg-Mermin-Wagner theorem states that a two-dimensional system cannot spontaneously break a continuous symmetry at finite temperature. This is supported by the observation of layer-dependent superconductivity in the quasi-two-dimensional superconductor NbSe2, in which the superconducting transition temperatur...
2311.14559v1
2023-11-29
Magnetic field simulations and measurements on the mini-ICAL detector
The ICAL (Iron Calorimeter) is a 51 kTon magnetized detector proposed by the INO collaboration. It is designed to detect muons with energies in the 1-20 GeV range. A magnetic field of about 1.5 T in the ICAL detector will be generated by passing a DC current through suitable copper coils. This will enable it to disting...
2311.17364v1
2023-11-30
Highly efficient and transferable interatomic potentials for α-iron and α-iron/hydrogen binary systems using deep neural networks
Artificial neural network potentials (NNPs) have emerged as effective tools for understanding atomic interactions at the atomic scale in various phenomena. Recently, we developed highly transferable NNPs for {\alpha}-iron and {\alpha}-iron/hydrogen binary systems (Physical Review Materials 5 (11), 113606, 2021). These ...
2311.18686v1
2023-12-08
Numerical determination of iron dust laminar flame speeds with the counterflow twin-flame technique
Iron dust counter-flow flames have been studied with the low-Mach-number combustion approximation. The model considers full coupling between the two phases, including particle/droplet drag. The dispersed phase flow strain relations are derived under the assumption of low Reynolds number conditions. The importance of so...
2312.04994v1
2023-12-19
The distribution of impactor core material during large impacts on Earth-like planets
Large impacts onto young rocky planets may transform their compositions, creating highly reducing conditions at their surfaces and reintroducing highly siderophile metals to their mantles. Key to these processes is the availability of an impactor's chemically reduced core material (metallic iron). It is, therefore, imp...
2312.12132v1
2023-12-30
Evidence of grain alignment by magnetically enhanced radiative torques from multi-wavelength dust polarization modeling of HL Tau
Atacama Large Millimeter/Submillimeter Array (ALMA) has revolutionized the field of dust polarization in protoplanetary disks across multiple wavelengths. Previous observations and empirical modeling suggested multiple mechanisms of dust polarization toward HL Tau, including grain alignment and dust scattering. However...
2401.00220v1
2024-02-13
A Search for Magnetized Quark Nuggets (MQNs), a Candidate for Dark Matter, Accumulating in Iron Ore
A search has been carried out for Magnetized Quark Nuggets (MQNs) accumulating in iron ore over geologic time. MQNs, which are theoretically consistent with the Standard Models of Physics and of Cosmology, have been suggested as dark-matter candidates. Indirect evidence of MQNs has been previously inferred from observa...
2402.08163v1
2024-03-28
Combine Influences of Nanoparticulate Hematite Thin Film Thickness, Roughness, and Weight on Its Photoelectrochemical Performance and Viscous/ Thermal Characteristics of Source Precursor
The objective of this work was to investigate the photoelectrochemical (PEC) performance of nanoparticulate hematite thin film photoelectrodes prepared by a soft-chemistry route. Two cost-effective thin film fabrication techniques were employed to deposit the hematite film. First, the film was deposited on conducting g...
2403.19069v1
2024-03-28
Synthetic Oil Gels With Organoclays In The Formulation Of Magnetorheological Fluids
Magnetorheological fluids (MRF) are smart composite materials that, under an external magnetic field, show a reversible solid-liquid transition in less than 10 ms. This study aimed to evaluate which organoclays would jellify a synthetic oil for the formulation of MRF. Three dispersant additives for carbonyl iron powder...
2403.19774v1
1998-06-25
Low-Metallicity Inhibition of Type Ia Supernovae and Galactic and Cosmic Chemical Evolution
We introduce a metallicity dependence of Type Ia supernova (SN Ia) rate into the Galactic and cosmic chemical evolution models. In our SN Ia progenitor scenario, the accreting white dwarf (WD) blows a strong wind to reach the Chandrasekhar mass limit. If the iron abundance of the progenitors is as low as [Fe/H] < -1, t...
9806335v1
1999-02-08
Metallicity Gradients in the Intracluster Gas of Abell 496
Analysis of spatially resolved ASCA spectra of the intracluster gas in Abell 496 confirms there are mild metal abundance enhancements near the center, as previously found by White et al. (1994) in a joint analysis of Ginga LAC and Einstein SSS spectra. Simultaneous analysis of spectra from all ASCA instruments (SIS + G...
9902112v2
1999-03-24
Further studies of 1E 1740.7-2942 with ASCA
We report the ASCA results of the Great Annihilator 1E 1740.7-2942 obtained with five pointing observations in a time span of 3.5 years. The X-ray spectrum for each period is well fitted with a single power-law absorbed by a high column of gas. The X-ray flux changes by a factor of 2 from period to period, but the othe...
9903376v2
1999-05-20
Soft X-ray spectroscopy of Compton-thick Seyfert 2 galaxies with BeppoSAX
We present a X-ray spectroscopic study of the bright Compton-thick Seyfert 2s NGC1068 and the Circinus Galaxy, performed with BeppoSAX. Matt et al. (1997 and 1998) interpreted the spectrum above 4 keV as the superposition of Compton reflection and warm plasma scattering of the nuclear radiation. When this continuum is ...
9905261v1
2000-02-22
Non-LTE Effects in Berylium Abundances
In this work we analyze the beryllium-iron chemical diagram from the point of view of non-LTE effects. Be abundances were re-calculated by considering non-LTE corrections in ionization equilibrium (logg) and Fe abundances ([Fe/H]). These corrections seem do not affect the linear relation between Be-Fe for metal-poor st...
0002408v1
2000-05-01
Reflected Iron Line From a Source Above a Kerr Black Hole Accretion Disc
In this paper we present a fully relativistic approach to modelling both the continuum emission and the reflected fluorescent iron line from a primary X-ray source near a Kerr black hole. The X-ray source is located above an accretion disc orbiting around the black hole. The source is assumed to be a static point sourc...
0005020v1
2000-05-30
BeppoSAX broad-band observations of low-redshift quasars: Spectral curvature and iron K_alpha lines
We present results from BeppoSAX observations of 10 low redshift quasars. The quasars are part of the Laor et al. (1997) sample of 23 optically selected PG quasars with redshift <0.4 and low Galactic absorption along the line of sight. Significant spectral curvature is detected for the 6 quasars with the highest signal...
0005567v1
2000-10-20
Abundances and Evolution of Lithium in the Galactic Halo and Disk
We have measured the Li abundance of 18 stars with -2 <~ [Fe/H] ~< -1 and 6000 K <~ Teff <~ 6400 K, a parameter range that was poorly represented in previous studies. We examine the Galactic chemical evolution (GCE) of this element, combining these data with previous samples of turnoff stars over the full range of halo...
0010411v1
2000-11-28
Presupernova Evolution with Improved Rates for Weak Interactions
Recent shell-model calculations of weak-interaction rates for nuclei in the mass range A = 45 - 65 have resulted in substantial revisions to the hitherto standard set of Fuller, Fowler, & Newman (FFN). In particular, key electron-capture rates, such as that for Co60 are much smaller. We consider here the effects of the...
0011507v1
2001-01-24
Issues of LiBeB, Oxygen and Iron Evolution
We discuss the highlights of our recent research, specifically the refractory vs. volatile interpretation of the rise of [O/Fe] with decreasing [Fe/H], and the issue of primary vs. secondary evolution of Be.
0101432v1
2001-12-05
Caught in the Act; Chandra Observations of Microlensing of the Radio-Loud Quasar MG J0414+0534
We present results from monitoring of the distant (z = 2.64), gravitationally lensed quasar MG J0414+0534 with the Chandra X-ray Observatory. An Fe Ka line at 6.49 +/- 0.09 keV (rest-frame) with an equivalent width of ~ 190eV consistent with fluorescence from a cold medium is detected at the 99 percent confidence level...
0112112v1
2001-12-07
Fe Kαemission from photoionized slabs: the impact of the iron abundance
Iron K\alpha emission from photoionized and optically thick material is observed in a variety of astrophysical environments including X-ray binaries, active galactic nuclei, and possibly gamma-ray bursts. This paper presents calculations showing how the equivalent width (EW) of the Fe K line depends on the iron abundan...
0112179v1
2002-06-04
Resolving the Effects of Resonant X-ray Line Scattering in Cen X-3 with Chandra
The massive X-ray binary Cen X-3 was observed over approximately one quarter of the system's 2.08 day orbit, beginning before eclipse and ending slightly after eclipse center with the Chandra X-ray Observatory using its High-Energy Transmission Grating Spectrometer. The spectra show K shell emission lines from hydrogen...
0206065v2
2002-12-03
Fluorescent iron lines as a probe of astrophysical black hole systems
(abridged) With most physicists and astrophysicists in agreement that black holes do indeed exist, the focus of astrophysical black hole research has shifted to the detailed properties of these systems. Nature has provided us with an extremely useful probe of the region very close to an accreting black hole - X-ray irr...
0212065v2
2003-04-01
XMM-Newton observations of Broad FeKalpha emission from a Seyfert 1.9 galaxy MCG-5-23-16
XMM-Newton observations of the bright Seyfert 1.9 galaxy MCG-5-23-16 have revealed a broad FeKalpha emission line which is nearly symmetric in contrast to the broad and red-shifted asymmetric FeKalpha line sometimes observed from Seyfert 1 galaxies. The FeKalpha line has two distinct components - a narrow unresolved co...
0304037v1
2003-12-01
On Sensitivity of Cherenkov Radiation to the Dynamics of High Energy Cosmic Ray Interactions
A simulation study of the effects resulting from creation of quark--gluon plasma in high energy collisions of cosmic iron nuclei with the air has been carried out. The Cherenkov light emission has been found to reveal some features of the dynamics of high energy hadronic interactions.
0312027v1
2003-12-11
IZw1 observed with XMM-Newton: Low-energy spectral complexity, iron lines, and hard X-ray flares
We present a 20 ks XMM-Newton observation of the prototypical Narrow-Line Seyfert 1 galaxy IZw1. The best-fit model to the data is a double blackbody plus a dominant power-law, on which complex soft absorption (possibly a blended edge or absorption lines) and/or OVII emission are superimposed, as well as strong Fe Kalp...
0312298v1
2003-12-12
XMM-Newton view of the prototype narrow-line Seyfert 1 galaxy I Zw 1
We present results based on an XMM-Newton observation of the prototype narrow-line Seyfert 1 galaxy I Zw 1 performed in June 2002. The 0.6-12 keV spectrum is well described by a steep power-law (Gamma\sim 2.3) and a weak soft blackbody component (kT \sim 200 eV) below 2 kev. The soft X-ray excess emission is featureles...
0312342v1
2004-03-02
Abundance differences between components of wide binaries
In this paper we present iron abundance analysis for 23 wide binaries with main sequence components in the temperture range 4900-6300 K, taken from the sample of the pairs currently included in the radial velocity planet search on going at the TNG. The use of a line-by-line differential analysis technique between the c...
0403051v2
2004-03-04
S4N: A Spectroscopic Survey of Stars in the Solar Neighborhood
[ABRIDGED] We report the results of a high-resolution spectroscopic survey of all the stars more luminous than Mv = 6.5 mag within 14.5 pc from the Sun. We derive stellar parameters and perform a preliminary abundance and kinematic analysis of the F-G-K stars in the sample. The inferred metallicity ([Fe/H]) distributio...
0403108v1
2004-05-18
Iron K-alpha Fluorescent Line Profiles from Spiral Accretion Flows in AGNs
We present 6.4 keV iron K-alpha fluorescent line profiles predicted for a relativistic black hole accretion disk in the presence of a spiral motion in Kerr geometry, the work extended from an earlier literature motivated by recent magnetohydrodynamic (MHD) simulations. The velocity field of the spiral motion, superpose...
0405337v1
2004-08-23
An extreme, blueshifted iron line profile in the Narrow Line Seyfert 1 PG 1402+261; an edge-on accretion disk or highly ionized absorption?
We report on a short XMM-Newton observation of the radio-quiet Narrow Line Seyfert 1 PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6-9 keV in the rest frame. This feature can be modeled by an unusually strong (equivalent width 2 keV) and very broad (FWHM velocity of 110000 ...
0408403v1
2004-10-28
Composition of the Solar Interior: Information from Isotope Ratios
Measurements are reviewed showing that the interior of the Sun, the inner planets, and ordinary meteorites consist mostly of the same elements: Iron, oxygen, nickel, silicon, magnesium, sulfur and calcium. These results do not support the standard solar model.
0410717v1
2005-11-15
Kappa-Mechanism Excitation of Retrograde Mixed Modes in B-Type Stars
The stability of retrograde mixed modes in rotating B-type stars is investigated. It is found that these modes are susceptible to kappa-mechanism excitation, due to the iron opacity bump at log T ~ 5.3. The findings are discussed in the context of the pulsation of SPB and Be stars.
0511455v1
2006-08-08
XMM-Newton high-resolution spectroscopy reveals the chemical evolution of M 87
We present here a study of chemical abundances in the giant elliptical galaxy M 87 using high-resolution spectra obtained with the Reflection Grating Spectrometers during two deep XMM-Newton observations. While we confirm the two-temperature structure of the inter-stellar medium (ISM) in M 87, we also show that a conti...
0608177v1
2006-09-08
Iron and Nickel Line Diagnostics for the Galactic Center Diffuse Emission
We have observed the diffuse X-ray emission from the Galactic center (GC) using the X-ray Imaging Spectrometer (XIS) on Suzaku. The high-energy resolution and the low-background orbit provide excellent spectra of the GC diffuse X-rays (GCDX). The XIS found many emission lines in the GCDX near the energy of K-shell tran...
0609215v1
2006-10-16
Helium and Iron in X-ray galaxy clusters
I discuss the role of the sedimentation of helium in galaxy cluster cores on the observed X-ray properties and present a history of the metal accumulation in the ICM, with new calculations with respect to my previous work following the recent evidence of a bi-modal distribution of the delay time in Supernovae Type Ia.
0610466v1
2006-10-17
Suzaku discovery of iron absorption lines in outburst spectra of the X-ray transient 4U 1630-472
We present the results of six Suzaku observations of the recurrent black hole transient 4U1630-472 during its decline from outburst from February 8 to March 23 in 2006. All observations show the typical high/soft state spectral shape in the 2-50keV band, roughly described by an optically thick disk spectrum in the soft...
0610496v1
2006-11-01
Magnetic flares in Active Galactic Nuclei: Modeling the iron Kalpha-line
The X-ray spectra of Active Galactic Nuclei (AGN) are complex and vary rapidly in time as seen in recent observations. Magnetic flares above the accretion disk can account for the extreme variability of AGN. They also explain the observed iron Kalpha fluorescence lines. We present radiative transfer modeling of the X-r...
0611020v1