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2006-11-03 | Suzaku Spectroscopy Study of Hard X-Ray Emission in the Arches Cluster | We present the results of a Suzaku study of the Arches cluster. A high S/N
spectrum in the 3-12 keV band was obtained with the XIS. We found that the
spectrum consists of a thermal plasma, a hard power-law tail, and two Gaussian
lines. The plasma component (kT~2.2 keV) is established from the presence of
CaXIX and FeXX... | 0611104v1 |
2001-02-16 | Finite-temperature magnetism of transition metals: an LDA+DMFT approach | We present an ab initio quantum theory of the finite temperature magnetism of
iron and nickel. A recently developed technique which combines dynamical
mean-field theory with realistic electronic structure methods, successfully
describes the many-body features of the one electron spectra and the observed
magnetic moment... | 0102297v1 |
2002-03-07 | Segmented Band Mechanism for Itinerant Ferromagnetism | We introduce a novel mechanism for itinerant ferromagnetism, which is based
on a simple two-band model, and using numerical and analytical methods, we show
that the Periodic Anderson Model (PAM) contains this mechanism. We propose that
the mechanism, which does not assume an intra-atomic Hund's coupling, is
present in ... | 0203172v1 |
2002-04-08 | Determining the Saddle Point in Micromagnetic Models of Magnetization Switching | A numerical model of single-domain nanoscale iron magnets fabricated using
scanning-microscope-assisted chemical vapor deposition is simulated using
finite-temperature micromagnetics. A Projective-dynamics method is used to
determine the magnetization at the saddle point as a function of temperature.
This magnetization... | 0204180v1 |
2002-09-06 | Electric conductivity of lead iron niobate | Results of d.c. electric conductivity and Seebeck coefficient measurements
for PFN, PFN+Li ceramic samples and PFN single crystals are presented. Marked
influence of doping with lithium on the value of electric conductivity, and on
the type of electric conductance has been found. | 0209154v1 |
2002-09-12 | Some physical properties of lead iron niobate | The results of the X-ray, microscopic, magnetic, and dielectric measurements
performed for PFN single crystals and ceramic samples are presented. The
influence of the technological conditions on selected physical properties of
the materials examined is shown. | 0209289v1 |
2004-09-10 | Reversal Modes of Simulated Iron Nanopillars in an Obliquely Oriented Field | Stochastic micromagnetic simulations are employed to study switching in
three-dimensional magnetic nanopillars exposed to highly misaligned fields. The
switching appears to proceed through two different decay modes, characterized
by very different average lifetimes and different average values of the
transverse magneti... | 0409277v1 |
2006-09-29 | Negative four-terminal resistance as a probe of crossed Andreev reflection | We report on the experimental investigation of electronic transport in
superconductor-ferromagnet spin-valve structures. Our samples consist of two
ferromagnetic iron leads forming planar tunnel contacts to a superconducting
aluminum wire. At energies below the superconducting gap, we observe a negative
four-probe resi... | 0609766v1 |
2005-05-23 | The Cyborg Astrobiologist: Scouting Red Beds for Uncommon Features with Geological Significance | The `Cyborg Astrobiologist' (CA) has undergone a second geological field
trial, at a red sandstone site in northern Guadalajara, Spain, near Riba de
Santiuste. The Cyborg Astrobiologist is a wearable computer and video camera
system that has demonstrated a capability to find uncommon interest points in
geological image... | 0505058v1 |
1998-05-27 | Signals of phase transition in atmospheric showers | We discuss collective effects like percolation, quark gluon plasma, or string
fusion and their effect on the longitudinal development of high energy showers
in air. It is shown that iron-air showers could develop more slowly than
expected and produce the observed change in the slope of $X_max$ at the highest
energies. | 9805475v1 |
2007-06-01 | Unveiling the broad band X-ray continuum and iron line complex in Mkr 841 | Mkr 841 is a bright Seyfert 1 galaxy known to harbor a strong soft excess and
a variable K$\alpha$ iron line. It has been observed during 3 different periods
by XMM for a total cumulated exposure time of $\sim$108 ks. We present in this
paper a broad band spectral analysis of the complete EPIC-pn data sets. We were
abl... | 0706.0134v1 |
2007-10-04 | Broad band X-ray spectroscopy of A0535+262 with SUZAKU | The transient X-ray binary pulsar A0535+262 was observed with Suzaku on 2005
September 14 when the source was in the declining phase of the August-September
minor outburst. The ~103 s X-ray pulse profile was strongly energy dependent, a
double peaked profile at soft X-ray energy band (<3 keV) and a single peaked
smooth... | 0710.0961v1 |
2008-04-16 | Discovery of superstrong, fading, iron line emission and double-peaked Balmer lines of the galaxy SDSSJ0952+2143 - the light echo of a huge flare | We report the discovery of superstrong, fading, high-ionization iron line
emission in the galaxy SDSSJ095209.56+214313.3 (SDSSJ0952+2143 hereafter),
which must have been caused by an X-ray outburst of large amplitude.
SDSSJ0952+2143 is unique in its strong multiwavelength variability; such a
broadband emission-line and... | 0804.2670v1 |
2008-05-26 | Around the Pair Instability Valley - Massive SN Progenitors | The discovery of the extremely luminous supernova SN 2006gy, possibly
interpreted as a pair instability supernova, renewed the interest in very
massive stars. We explore the evolution of these objects, which end their life
as pair instability supernovae or as core collapse supernovae with relatively
massive iron cores,... | 0805.3874v1 |
2008-06-05 | Cu, Pu and Fe high Tc superconductors: all the same mechanism! | The new iron based high Tc superconductors with Tc up to 55 K have stirred
new interest in this field. It is consensus that the BCS mechanism is not able
to explain the high Tc's. In the following we propose that spin holes in
antiferromagnetic clusters combine to make nonmagnetic bipolarons, which can
condense and lea... | 0806.0900v1 |
2008-06-22 | The most massive core collapse supernova progenitors | The discovery of the extremely luminous supernova SN 2006gy, possibly
interpreted as a pair instability supernova, renewed the interest in very
massive stars. We explore the evolution of these objects, which end their life
as pair instability supernovae or as core collapse supernovae with relatively
massive iron cores,... | 0806.3544v2 |
2008-07-08 | The influence of chemical composition on the properties of Cepheid stars. II-The iron content | The Cepheid period-luminosity (PL) relation is unquestionably one of the most
powerful tools at our disposal for determining the extragalactic distance
scale. While significant progress has been made in the past few years towards
its understanding and characterization both on the observational and
theoretical sides, th... | 0807.1196v2 |
2008-09-21 | The Suzaku Observations of SS Cygni in Quiescence and Outburst | We present results from the Suzaku observations of the dwarf nova SS Cyg in
quiescence and outburst in 2005 November. Owing to high sensitivity of the HXD
PIN detector and high spectral resolution of the XIS, we have determined
parameters of the plasma with unprecedented precision. The maximum temperature
of the plasma... | 0809.3559v2 |
2008-10-14 | Probing the accretion disk and central engine structure of NGC4258 with Suzaku and XMM-Newton observations | [abridged] We present an X-ray study of the low-luminosity active galactic
nucleus (AGN) in NGC4258 using data from Suzaku, XMM-Newton, and the Swift/BAT
survey. We find that signatures of X-ray reprocessing by cold gas are very weak
in the spectrum of this Seyfert-2 galaxy; a weak, narrow fluorescent-Kalpha
emission l... | 0810.2543v1 |
2008-11-24 | Fe-based superconductors: unity or diversity? | Does the high temperature superconductivity observed in the newly discovered
iron-pnictide materials represent another example of the same essential physics
responsible for superconductivity in the cuprates, or does it embody a new
mechanism? | 0811.3973v1 |
2008-12-06 | Piezonuclear Neutrons | We report the results of neutron measurements carried out during the
application of ultrasounds to a solution containing only stable elements like
Iron and Chlorine, without any other radioactive source of any kind. These
measurements, carried out by CR39 detectors and a Boron TriFouride electronic
detector, evidenced ... | 0812.1272v1 |
2009-03-01 | Excitonic spin density wave state in iron pnictides | We examine the appearance of a spin density wave in the FeAs parent compounds
due to an excitonic instability. Using a realistic four-band model, we show
that the magnetic state depends very sensitively upon the details of the band
structure. We demonstrate that an orthorhombic distortion of the crystal
enhances the st... | 0903.0124v1 |
2009-03-25 | Isotropic superconducting state and high critical currents in Fe1+yTe1-xSx single crystals | We report single crystal growth and a study of superconducting properties in
Fe_{1+y}Te_{1-x}S_{x}. We demonstrate the smallest upper critical field
anisotropy, gamma=H_{c2}^{//c}/H_{c2}^{//a}, among all iron based
superconductors, the value of gamma reaches 1.05 at T=0.65T_{C} for
Fe_{1.09}Te_{0.89}S_{0.11}, while sti... | 0903.4430v2 |
2009-10-21 | Correspondence on "Electronic correlations in the iron pnictides" | I point out that the observed discrepancy between the measured and calculated
Drude weights in LaFePO may be caused not only by mass renormalization, but
also by a DFT inaccuracy in determining the relative positions of the hole and
electron band. | 0910.4117v1 |
2009-10-28 | Experimentally Realized Correlated Electron Materials: From Superconductors to Topological Insulators | Recent discoveries, as well as open questions, in experimentally realized
correlated electron materials are reviewed. In particular, high temperature
superconductivity in the cuprates and in the recently discovered iron
pnictides, possible chiral p-wave superconductivity in strontium ruthenate, the
search for quantum s... | 0910.5513v1 |
2009-12-09 | Pairing mechanism in Fe pnictide superconductors | By applying an exact unitary transformation to a two-band hamiltonian which
also includes the effects due to large pnictogen polarizabilities, we show that
an attractive spin-mediated Hubbard term appears in the $d_{xz}$, $d_{yz}$
nearest-neighbour channel. This pairing mechanism implies a singlet
superconducting order... | 0912.1811v1 |
2009-12-18 | Nodes to the grindstone: viewpoint on ``Band- and momentum-dependent electron dynamics in superconducting Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ as seen via electronic Raman scattering" [arXiv:0910.0898] | Raman spectroscopy of a cobalt-doped iron-pnictide superconductor reveals the
complex electronic structure of the superconducting state in this material.
[Viewpoint on Phys. Rev. B 80, 180510 (2009), arXiv:0910.0898] | 0912.3756v1 |
2010-03-19 | New Baade-Wesselink distances and radii for four metal-rich Galactic Cepheids | We provided accurate estimates of distances, radii and iron abundances for
four metal-rich Cepheids, namely V340 Ara, UZ Sct, AV Sgr and VY Sgr. The main
aim of this investigation is to constrain their pulsation properties and their
location across the Galactic inner disk. We adopted new accurate NIR (J,H,K)
light curv... | 1003.3854v1 |
2010-05-17 | Interatomic exchange coupling of BCC iron | We performed first-principle calculations on the exchange interaction (EI)
between atoms in BCC-Fe strained volumetrically. Our results show that the
volume-dependence of the EI deviates considerably from the Bethe-Slater curve.
This behavior is discussed in terms of the on-site and/or inter-site direct
exchange intera... | 1005.2931v1 |
2010-06-16 | Apparent high metallicity in 3-4 keV galaxy clusters: the inverse iron-bias in action in the case of the merging cluster Abell 2028 | Recent work based on a global measurement of the ICM properties find evidence
for an increase of the iron abundance in galaxy clusters with temperature
around 2-4 keV up to a value about 3 times larger than that typical of very hot
clusters. We have started a study of the metal distribution in these objects
from the sa... | 1006.3255v2 |
2010-06-18 | The Type Ia Supernova Rate in Redshift 0.5--0.9 Galaxy Clusters | Supernova (SN) rates are potentially powerful diagnostics of metal enrichment
and SN physics, particularly in galaxy clusters with their deep,
metal-retaining potentials and relatively simple star-formation histories. We
have carried out a survey for supernovae (SNe) in galaxy clusters, at a
redshift range 0.5<z<0.9, u... | 1006.3757v1 |
2010-07-09 | The broad-band X-ray spectrum of the Seyfert 1 galaxy, MCG+8-11-11 | We present a long (100 ks) Suzaku observation of one of the X-ray brightest
AGN, MCG+8-11-11. These data were complemented with the 54-month Swift BAT
spectrum, allowing us to perform a broad-band fit in the 0.6-150 keV range. The
fits performed in the 0.6-10 keV band give consistent results with respect to a
previous ... | 1007.1638v1 |
2010-07-16 | Magnetism and Charge Dynamics in Iron Pnictides | In a wide variety of materials, such as copper oxides, heavy fermions,
organic salts, and the recently discovered iron pnictides, superconductivity is
found in close proximity to a magnetically ordered state. The character of the
proximate magnetic phase is thus believed to be crucial for understanding the
differences ... | 1007.2867v1 |
2010-10-29 | The Stellar Abundances for Galactic Archaeology (SAGA) Database II - Implications for Mixing and Nucleosynthesis in Extremely Metal-Poor Stars and Chemical Enrichment of the Galaxy | We discuss the characteristics of known extremely metal-poor (EMP) stars in
the Galaxy using the Stellar Abundances for Galactic Archaeology (SAGA)
database (Suda et al. 2008, PASJ, 60, 1159).The analyses of carbon-enhanced
stars in our sample suggest that the nucleosynthesis in AGB stars can
contribute to the carbon e... | 1010.6272v1 |
2011-01-18 | Discovery of strong Iron Kα emitting Compton thick quasars at z=2.5 and 2.9 | We report the detection of the 6.4 keV Iron K{\alpha} emission line in two
infrared-luminous, massive, star-forming BzK galaxies at z = 2.578 and z = 2.90
in the CDF-S. The Chandra 4 Ms spectra of BzK4892 and BzK8608 show a reflection
dominated continuum with strong Iron lines, with rest-frame equivalent widths
EW-2.3 ... | 1101.3478v1 |
2011-02-02 | Gold slows down the growth of helium bubble in iron | We predict by first-principles calculations that Au have strong affinity to
He in bcc Fe. The Au-Au bonding in the segregated Au layer at the He bubble
surface is stronger than Fe-Fe and Au-Fe interactions; therefore this layer
becomes an effective barrier to further He and slows down the bubble growth. | 1102.0355v1 |
2011-03-07 | Reversibly tuning the insulating and superconducting state in KxFe2-ySe2 crystals by post-annealing | Since the discovery of superconductivity at 26 K in oxy-pnictide
LaFeAsO1-xFx, enormous interests have been stimulated in the field of condensed
matter physics and material sciences. Among the many kind of structures in the
iron pnictide superconductors, FeSe with the PbO structure has received special
attention since ... | 1103.1347v1 |
2011-04-07 | Insight Into the Formation of the Milky Way Through Cold Halo Substructure. II. The Elemental Abundances of ECHOS | We determine the average metallicities of the elements of cold halo
substructure (ECHOS) that we previously identified in the inner halo of the
Milky Way within 17.5 kpc of the Sun. As a population, we find that stars
kinematically associated with ECHOS are chemically distinct from the background
kinematically smooth i... | 1104.1424v1 |
2011-05-10 | Superconductivity in the Honeycomb-Lattice Pnictide SrPtAs | We report superconductivity in the honeycomb-lattice pnictide SrPtAs with Tc
= 2.4 K. To our knowledge, SrPtAs is the first superconducting pnictide with a
honeycomb lattice structure. Our finding opens up new playground to develop
pnictide superconductors with honeycomb lattices, in addition to square
lattices known i... | 1105.1848v1 |
2011-05-18 | Specifics of impurity effects in ferropnictide superconductors | Effects of impurities and disorder on quasiparticle spectrum in
superconducting iron pnictides are considered. Possibility for occurrence of
localized energy levels due to impurities within the superconducting gap and
the related modification of band structure and of superconducting order
parameter are discussed. The e... | 1105.3608v1 |
2011-06-02 | X-ray Spectroscopy of the High Mass X-ray Binary Pulsar Centaurus X-3 over its Binary Orbit | We present a comprehensive spectral analysis of the high mass X-ray binary
(HMXB) pulsar Centaurus X-3 with the Suzaku observatory covering nearly one
orbital period. The light curve shows the presence of extended dips which are
rarely seen in HMXBs. These dips are seen up to as high as ~40 keV. The pulsar
spectra duri... | 1106.0370v1 |
2011-06-29 | Phase Separation and Superconductivity in Fe1+xTe0.5Se0.5 | Fe1+xTe0.5Se0.5 is the archetypical iron-based superconductor. Here we show
that the superconducting state is controlled by the stacking of its anti-PbO
layers, such that homogeneous ordering hinders superconductivity and the
highest volume fractions are observed in phase separated structures as
evidenced by either a d... | 1106.5955v1 |
2011-12-19 | XMM-Newton observation of 4U 1820-30: Broad band spectrum and the contribution of the cold interstellar medium | We present the analysis of the bright X-ray binary 4U 1820-30, based mainly
on XMM-Newton-RGS data, but using complementary data from XMM-Epic, Integral,
and Chandra-HETG, to investigate different aspects of the source. The broad
band continuum is well fitted by a classical combination of black body and
Comptonized emi... | 1112.4349v1 |
2012-02-27 | Testing the No-Hair Theorem with Observations in the Electromagnetic Spectrum. IV. Relativistically Broadened Iron Lines | According to the no-hair theorem, astrophysical black holes are fully
characterized by their masses and spins and are described by the Kerr metric.
This theorem can be tested observationally by measuring (at least) three
different multipole moments of the spacetimes of black holes. In this paper, we
calculate the profi... | 1202.6069v2 |
2012-03-20 | Neutrino cooling rates due to $^{54,55,56}$Fe for presupernova evolution of massive stars | Accurate estimate of neutrino energy loss rates are needed for the study of
the late stages of the stellar evolution, in particular for cooling of neutron
stars and white dwarfs. Proton-neutron quasi-particle random phase
approximation (pn-QRPA) theory has recently being used for a microscopic
calculation of stellar we... | 1203.4344v1 |
2012-03-21 | Ground and excited states Gamow-Teller strength distributions of iron isotopes and associated capture rates for core-collapse simulations | This paper reports on the microscopic calculation of ground and excited
states Gamow-Teller (GT) strength distributions, both in the electron capture
and electron decay direction, for $^{54,55,56}$Fe. The associated electron and
positron capture rates for these isotopes of iron are also calculated in
stellar matter. Th... | 1203.4675v1 |
2012-03-22 | Thermal and electrical conductivity of iron at Earth's core conditions | The Earth acts as a gigantic heat engine driven by decay of radiogenic
isotopes and slow cooling, which gives rise to plate tectonics, volcanoes, and
mountain building. Another key product is the geomagnetic field, generated in
the liquid iron core by a dynamo running on heat released by cooling and
freezing to grow th... | 1203.4970v1 |
2012-03-22 | Enhancement of superconducting transition temperature of FeSe by intercalation of a molecular spacer layer | The recent discovery of high temperature superconductivity in a layered iron
arsenide has led to an intensive search to optimize the superconducting
properties of iron-based superconductors by changing the chemical composition
of the spacer layer that is inserted between adjacent anionic iron arsenide
layers. Until now... | 1203.5046v2 |
2012-04-05 | "Cigar" Fermi surface as a possible requisite for superconductivity in iron-based superconductors | Recently discovered A-Fe-Se (A - alkali metal) materials have questioned the
most popular theories of iron-based superconductors because of their unusual
electronic structure [1]. Controversial photoemission data taken in the
superconducting state [2-7] are in conflict with highly magnetic state seen by
neutron-, muSR-... | 1204.1316v1 |
2012-06-03 | Fe-C and Fe-H systems at pressures of the Earth's inner core | The solid inner core of the Earth is predominantly composed of iron alloyed
with several percent Ni and some lighter elements, Si, S, O, H, and C being the
prime candidates. There have been a growing number of papers investigating C
and H as possible light elements in the core, but the results are
contradictory. Here, ... | 1206.0467v1 |
2012-06-28 | High-spin low-spin transition | Temperature dependent nuclear inelastic-scattering (NIS) of synchrotron
radiation was applied to investigate both spin states of the spin-crossover
complex [Fe(tpa)(NCS)(2)] (tpa = tris(2-pyridylmethyl)amine). A remarkable
increase of the iron-ligand bond stretching upon spin crossover has
unambiguously been identified... | 1206.6683v1 |
2012-08-03 | The effect of frame dragging on the iron K alpha line in X-ray binaries | The clear characteristic timescale picked out by the low frequency
quasi-periodic oscillations (QPOs) seen in many black hole and neutron star
binaries has the potential to provide a very powerful diagnostic of the inner
regions of the accretion flow. However, this potential cannot be realised
without a quantitative mo... | 1208.0728v1 |
2012-08-06 | The UV/optical spectra of the Type Ia supernova SN 2010jn: a bright supernova with outer layers rich in iron-group elements | Radiative transfer studies of Type Ia supernovae (SNe Ia) hold the promise of
constraining both the time-dependent density profile of the SN ejecta and its
stratification by element abundance which, in turn, may discriminate between
different explosion mechanisms and progenitor classes. Here we present a
detailed analy... | 1208.1267v3 |
2012-09-07 | Phase relations in K_xFe_{2-y}Se_2 and the structure of superconducting K_xFe_2Se_2 via high-resolution synchrotron diffraction | Superconductivity in iron selenides has experienced a rapid growth, but not
without major inconsistencies in the reported properties. For
alkali-intercalated iron selenides, even the structure of the superconducting
phase is a subject of debate, in part because the onset of superconductivity is
affected much more delic... | 1209.1650v1 |
2012-10-10 | Composition of Near-Earth Asteroid (4179) Toutatis | Surface composition of near-Earth asteroid (4179) Toutatis is consistent with
an undifferentiated L-chondrite composition. This is inconsistent with early
observations that suggested high pyroxene iron content and a differentiated
body. | 1210.2853v1 |
2012-11-14 | Timing and Spectral Analysis of the Unusual X-Ray Transient XTE J0421+560/CI Camelopardalis | We present a detailed X-ray study of the 2003 XMM-Newton observation of the
High Mass X-ray Binary XTE J0421+560/CI Cam. The continuum of the X-ray
spectrum is well described by a flat power law (Gamma=1.0+/-0.2) with a large
intrinsic absorbing column (N_H=(4.4+/-0.5)\times10^{23} cm^{-2}). We have
decomposed the broa... | 1211.3400v1 |
2013-01-22 | First principles study of helium, carbon and nitrogen in austenite, dilute austenitic iron alloys and nickel | An extensive set of first-principles density functional theory calculations
have been performed to study the behaviour of He, C and N solutes in austenite,
dilute Fe-Cr-Ni austenitic alloys and Ni in order to investigate their
influence on the microstructural evolution of austenitic steel alloys under
irradiation. | 1301.5317v1 |
2013-03-25 | Broad iron line in the fast spinning neutron-star system 4U 1636-53 | We analysed the X-ray spectra of six observations, simultaneously taken with
XMM-Newton and Rossi X-ray Timing Explorer (RXTE), of the neutron star low-mass
X-ray binary 4U 1636-53. The observations cover several states of the source,
and therefore a large range of inferred mass accretion rate. These six
observations s... | 1303.6337v1 |
2013-04-03 | Universal formula for the muon-induced neutron yield | The experimental data on the yield of muon-induced neutrons for liquid
scintillator, iron and lead accumulated during 60 years of muon interaction
underground study have been analyzed. A universal formula connecting the yield
with muon energy loss in the matter and neutron production in hadronic and
electromagnetic sho... | 1304.0919v1 |
2013-06-20 | Unexpected radial trend of the iron abundance in a sample of monometallic Galactic globular clusters | We study the relationship between the iron abundance (IA) in red giant branch
(RGB) stars and their radial distribution (RD) in Galactic globular clusters
(GCs). We relied on publicly available archival data on IA in red giants (RGs)
of GCs. We built a sample of ten target GCs in which the number of these RGs
exceeded ... | 1306.4930v1 |
2013-07-29 | Effect of surface hydrogen on the anomalous surface segregation behavior of Cr in Fe-rich Fe-Cr alloys | The segregation behavior of Cr in dilute Fe-Cr alloys is known to be
anomalous since the main barrier for surface segregation of Cr in these alloys
arises not from the topmost surface layer but from the subsurface layer where
the solution energy of Cr is much more endothermic as compared to the topmost
surface layer. T... | 1307.7588v1 |
2013-09-23 | The diagnostic potential of Fe lines applied to protostellar jets | We investigate the diagnostic capabilities of the iron lines for tracing the
physical conditions of the shock-excited gas in jets driven by pre-main
sequence stars. We have analyzed the 300-2500 nm X-shooter spectra of two jets
driven by the pre-main sequence stars ESO-Halpha 574 and Par-Lup 3-4. Both
spectra are very ... | 1309.5827v1 |
2014-07-03 | The Composition of M-type asteroids II: Synthesis of spectroscopic and radar observations | This work updates and expands on results of our long-term radar-driven
observational campaign of main-belt asteroids (MBAs) focused on Bus-DeMeo Xc-
and Xk-type objects (Tholen X and M class asteroids) using the Arecibo radar
and NASA Infrared Telescope Facilities (Ockert-Bell et al. 2008; 2010; Shepard
et al. 2008; 20... | 1407.0750v1 |
2014-08-05 | Collective Mode at Lifshitz Transition in Iron-Pnictide Superconductors | We obtain the exact low-energy spectrum of two mobile holes in a t-J model
for an isolated layer in an iron-pnictide superconductor. The minimum d xz and
d yz orbitals per iron atom are included, with no hybridization between the
two. After tuning the Hund coupling to a putative quantum critical point (QCP)
that separa... | 1408.0864v4 |
2014-08-09 | Structure determination and coexistence of superconductivity and antiferromagnetic order in (Li0.8Fe0.2)OHFeSe | FeSe-derived superconductors show some unique behaviors relative to
iron-pnictide superconductors, which are very helpful to understand the
mechanism of superconductivity in high-Tc iron-based superconductors. The
low-energy electronic structure of the heavily electron-doped AxFe2Se2 (A=K,
Rb, Cs) demonstrates that int... | 1408.2006v1 |
2014-12-22 | Fe-based superconductors: seven years later | Iron-based superconductors were discovered seven years ago, in 2008. This
short review summarizes what we learned about these materials over the last
seven years, what are open questions, and what new physics we expect to extract
from studies of this new class of high-temperature superconductors. | 1412.7104v1 |
2015-01-07 | Superoxide reductase from Desulfoarculus baarsii: reaction mechanism and role of glutamate 47 and lysine 48 in catalysis | Superoxide reductase (SOR) is a small metalloenzyme that catalyzes reduction
of O(2)(*)(-) to H(2)O(2) and thus provides an antioxidant mechanism against
superoxide radicals. Its active site contains an unusual mononuclear ferrous
center, which is very efficient during electron transfer to O(2)(*)(-)
[Lombard, M., Font... | 1501.01442v1 |
2015-09-02 | Energy and matter | Our work is an approach between matter and energy. Using the famous equation
E = mc^2, Einstein and the Law of Universal Gravitation of Newton, we estimate
that a small amount matter converted into energy is needed to lift, using the
gravitational potential energy equation on the surface, a mountain of solid
iron or ev... | 1509.02892v1 |
2015-10-27 | Constraining distance and inclination angle of V4641 Sgr using ${\it SWIFT}$ and ${\it NuSTAR}$ observations during low soft spectral state | We present results from ${\it NuSTAR}$ and ${\it SWIFT}$/XRT joint spectral
analysis of V4641 Sgr during a disk dominated or soft state as well as a
powerlaw dominated or hard state. The soft state spectrum is well modeled by a
relativistically blurred disk emission, a powerlaw, a broad Iron line, two
narrow emission l... | 1510.07837v1 |
2015-12-17 | Disorder-promoted $C_4$-symmetric magnetic order in iron-based superconductors | In most iron-based superconductors, the transition to the magnetically
ordered state is closely linked to a lowering of structural symmetry from
tetragonal ($C_{4}$) to orthorhombic ($C_{2}$). However, recently, a regime of
$C_{4}$-symmetric magnetic order has been reported in certain hole-doped
iron-based superconduct... | 1512.05747v1 |
2016-01-22 | Revised Masses and Densities of the Planets around Kepler-10 | Determining which small exoplanets have stony-iron compositions is necessary
for quantifying the occurrence of such planets and for understanding the
physics of planet formation. Kepler-10 hosts the stony-iron world Kepler-10b
(K10b), and also contains what has been reported to be the largest solid
silicate-ice planet,... | 1601.06168v1 |
2016-01-13 | On electrical conductivity of melts of boron and its compounds under pressure | The electrical conductivity of melts of boron and its carbide (B4C), nitride
(BN), and phosphide (BP) has been studied at pressures to 7.7 GPa and
temperatures to 3500 K. It has been shown that these melts are good conductors
with specific electrical conductivity values comparable with that of iron melt
at ambient pres... | 1601.06828v1 |
2016-03-04 | FeS: Structure and Composition Relations to Superconductivity and Magnetism | Structure and composition of iron chalcogenides have a delicate relationship
with magnetism and superconductivity. In this report we investigate the iron
sulfide layered tetragonal phase (t-FeS), and compare with three-dimensional
hexagonal phase (h-FeS). X-ray diffraction reveals the absence of structural
transitions ... | 1603.01598v1 |
2016-04-21 | Transition from sign-reversed to sign-preserved Cooper-pairing symmetry in sulfur-doped iron selenide superconductors | An essential step toward elucidating the mechanism of superconductivity is to
determine the sign/phase of superconducting order parameter, as it is closely
related to the pairing interaction. In conventional superconductors, the
electron-phonon interaction induces attraction between electrons near the Fermi
energy and ... | 1604.06222v1 |
2016-06-03 | Quantum Transitions of Nematic Phases in a Spin-$1$ Bilinear-Biquadratic Model and Their Implications for FeSe | Since its discovery, iron-based superconductivity has been known to develop
near an antiferromagnetic order, but this paradigm fails in the iron
chalcogenide FeSe, whose single-layer version holds the record for the highest
superconducting transition temperature in the iron-based superconductors. The
striking puzzle th... | 1606.01235v4 |
2016-07-04 | Low-energy microscopic models for iron-based superconductors: a review | The development of sensible microscopic models is essential to elucidate the
normal-state and superconducting properties of the iron-based superconductors.
Because these materials are mostly metallic, a good starting point is an
effective low-energy model that captures the electronic states near the Fermi
level and the... | 1607.00865v2 |
2016-10-04 | Optical signatures of low spin Fe3+: a new probe for the spin state of bridgmanite and post-perovskite | Iron spin transition directly affects properties of lower mantle minerals and
can thus alter geophysical and geochemical characteristics of the deep Earth.
While the spin transition in ferropericlase has been vigorously established at
P ~ 60 GPa and 300 K, experimental evidence for spin transitions in other
rock-formin... | 1610.01048v1 |
2016-12-22 | The AMBRE project: Iron-peak elements in the solar neighbourhood | The aim of this paper is to characterise the abundance patterns of five
iron-peak elements (Mn, Fe, Ni, Cu, and Zn) for which the stellar origin and
chemical evolution are still debated. We automatically derived iron peak (Mn,
Fe, Ni, Cu, and Zn) and alpha element (Mg) chemical abundances for 4666 stars.
We used the bi... | 1612.07622v2 |
2017-01-31 | Heterodiffusion coefficients in α-iron | The diffusion of tungsten in {\alpha}-iron is important for the application
of ferritic-iron alloys to thermal power plants. These data, over a wide
temperature range across the Curie temperature, have been recently reported. We
show that these diffusion coefficients can be satisfactory reproduced in terms
of the bulk ... | 1701.08993v1 |
2017-08-18 | Diffuse X-Ray Sky in the Galactic Center | The Galactic Diffuse X-ray Emission (GDXE) in the Milky Way Galaxy is
spatially and spectrally decomposed into the Galactic Center X-ray Emission
(GCXE), the Galactic Ridge X-ray Emission (GRXE) and the Galactic Bulge X-ray
Emission (GBXE). The X-ray spectra of the GDXE are characterized by the strong
K-shell lines of ... | 1708.05501v1 |
2017-10-09 | Pressure-induced spin pairing transition of Fe$^{3+}$ in oxygen octahedra | High pressure can provoke spin transitions in transition metal-bearing
compounds. These transitions are of high interest not only for fundamental
physics and chemistry, but also may have important implications for
geochemistry and geophysics of the Earth and planetary interiors. Here we have
carried out a comparative s... | 1710.03192v1 |
2018-01-03 | Reconciling Magma-Ocean Crystallization Models with the present-day Structure of the Earth's mantle | Terrestrial planets are thought to experience episode(s) of large-scale
melting early in their history. Fractionation during magma-ocean freezing leads
to unstable stratification within the related cumulate layers due to
progressive iron enrichment upward, but the effects of incremental cumulate
overturns during MO cry... | 1801.00991v1 |
2018-01-03 | The formation of the heaviest elements | The rapid neutron-capture process needed to build up many of the elements
heavier than iron seems to take place primarily in neutron-star mergers, not
supernova explosions. | 1801.01190v1 |
2018-01-10 | Lifshitz transitions induced by magnetic field | The Fermi surface can be changed by different external conditions like, e.g.,
pressure or doping. It can lead to a change in the Fermi surface topology,
called as the Lifshitz transition. Here, we briefly describe the Lifshitz
transitions induced by the external magnetic field in a one-dimensional optical
lattice and i... | 1801.03556v1 |
2018-01-22 | Alternative explanations for extreme supersolar iron abundances inferred from the energy spectrum of Cygnus X-1 | Here we study a 1-200 keV energy spectrum of the black hole binary Cygnus X-1
taken with NuSTAR and Suzaku. This is the first report of a NuSTAR observation
of Cyg X-1 in the intermediate state, and the observation was taken during the
part of the binary orbit where absorption due to the companion's stellar wind
is min... | 1801.07267v1 |
2018-09-25 | Multiple topological states in iron-based superconductors | Topological insulators and semimetals as well as unconventional iron-based
superconductors have attracted major recent attention in condensed matter
physics. Previously, however, little overlap has been identified between these
two vibrant fields, even though the principal combination of topological bands
and supercond... | 1809.09977v1 |
2018-12-11 | Variable stars in Terzan 5: additional evidence of multi-age and multi-iron stellar populations | Terzan 5 is a complex stellar system in the Galactic bulge, harboring stellar
populations with very different iron content ({\Delta}[Fe/H] ~1 dex) and with
ages differing by several Gyrs. Here we present an investigation of its
variable stars. We report on the discovery and characterization of three RR
Lyrae stars. For... | 1812.04325v1 |
2019-02-06 | Iron oxide nanoparticles for magnetic hyperthermia | Assemblies of magnetic nanoparticles show a great potential for application
in biomedicine, in particular, in magnetic hyperthermia. However, to achieve
desired therapeutic effect in magnetic hyperthermia the assembly of
nanoparticles should have a sufficiently high specific absorption rate in
alternating magnetic fiel... | 1902.02220v1 |
2019-07-01 | A new Majorana platform in an Fe-As bilayer superconductor | Recently, iron-chalcogenide superconductors have emerged as a new and
promising platform for studying and manipulating Majorana zero mode (MZM). By
combining topological band structure and superconductivity in a multiband
material, they provide significant advantages such as higher superconducting
transition temperatur... | 1907.00904v1 |
2020-01-13 | Spectroscopic Evidence of Bilayer Splitting and Interlayer Pairing in an Iron Based Superconductor | In high temperature cuprate superconductors, the interlayer coupling between
the CuO$_2$ planes plays an important role in dictating superconductivity, as
indicated by the sensitive dependence of the critical temperature (T$_C$) on
the number of CuO$_2$ planes in one structural unit. In
Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta... | 2001.04082v1 |
2020-04-14 | Trans-iron Ge, As, Se, and heavier elements in the dwarf metal-poor stars, HD~19445, HD~84937, HD~94028, HD~140283, and HD~160617 | Spectra of unevolved metal-poor halo stars uniquely reflect the elemental
abundances incorporated during the earliest Galactic epoch. Their heavy-element
content is well understood as the products of neutron capture on iron-peak
elements. However, the lightest elements just past the iron peak, with atomic
number 30<Z<5... | 2004.06359v1 |
2020-04-23 | Neutral Iron Emission Lines From The Day-side Of KELT-9b -- The GAPS Programme With HARPS-N At TNG XX | We present the first detection of atomic emission lines from the atmosphere
of an exoplanet. We detect neutral iron lines from the day-side of KELT-9b (Teq
$\sim$ 4, 000 K). We combined thousands of spectrally resolved lines observed
during one night with the HARPS-N spectrograph (R $\sim$ 115, 000), mounted at
the Tel... | 2004.11335v1 |
2020-04-26 | Resolving the soft X-ray ultra fast outflow in PDS 456 | Past X-ray observations of the nearby luminous quasar PDS 456 (at $z=0.184$)
have revealed a wide angle accretion disk wind (Nardini et al. 2015), with an
outflow velocity of $\sim-0.25c$, as observed through observations of its
blue-shifted iron K-shell absorption line profile. Here we present three new
XMM-Newton obs... | 2004.12439v1 |
2020-06-09 | The lively accretion disk in NGC 2992. I. Transient iron K emission lines in the high flux state | We report on one of the brightest flux levels of the Seyfert 2 galaxy NGC
2992 ever observed in X-rays, on May 2019. The source has been monitored every
few days from March 26, 2019 to December 14, 2019 by Swift-XRT, and
simultaneous XMM-Newton (250 ks) and NuSTAR (120 ks) observations were
triggered on May 6, 2019. Th... | 2006.05280v1 |
2020-08-14 | New luminous blue variable candidates in the NGC 247 galaxy | We search for LBV stars in galaxies outside the Local Group. Here we present
a study of two bright $H\alpha$ sources in the NGC 247 galaxy. Object
j004703.27-204708.4 ($M_V=-9.08 \pm 0.15^m$) shows the spectral lines typical
for well-studied LBV stars: broad and bright emission lines of hydrogen and
helium He I with P ... | 2008.06215v1 |
2020-09-11 | An Extraordinary Response of Iron Emission to the Central Outburst in a Tidal Disruption Event Candidate | Understanding the origin of \feii\ emission is important because it is
crucial to construct the main sequence of Active Galactic Nuclei (AGNs).
Despite several decades of observational and theoretical effort, the location
of the optical iron emitting region and the mechanism responsible for the
positive correlation bet... | 2009.05243v2 |
2020-12-01 | Variability in NGC 3201 giant stars and its impact on their spectroscopic [Fe/H] determination | We present the analysis of 34 light curves in $V$ and $I$ of 17 giant stars
in the globular cluster NGC 3201, to check if such stars are variable and if
their variability has some kind of impact on the iron abundance as obtained
from spectroscopic measurements. First, we computed the Generalized
Lomb-Scargle and Phase ... | 2012.00520v1 |
2020-12-09 | First measurement using a nuclear emulsion detector of the $ν_μ$ charged-current cross section on iron around the 1$\,$GeV energy region | We have carried out $\nu_{\mu}$ charged-current interaction measurement on
iron using an emulsion detector exposed to the T2K neutrino beam in the J-PARC
neutrino facility. The data samples correspond to 4.0$\times$10$^{19}$ protons
on target, and the neutrino mean energy is 1.49$\,$GeV. The emulsion detector
is suitab... | 2012.05221v2 |
2021-01-03 | Magnetic surface reconstruction in the van-der-Waals antiferromagnet Fe$_{1+x}$Te | Fe$_{1+x}$Te is a two dimensional van der Waals antiferromagnet that becomes
superconducting on anion substitution on the Te site. The parent phase of
Fe$_{1+x}$Te is sensitive to the amount of interstitial iron situated between
the iron-tellurium layers displaying collinear magnetic order coexisting with
low temperatu... | 2101.00569v1 |
2021-03-04 | Crater shape as a possible record of the impact environment of metallic bodies: Effects of temperature, impact velocity and impactor density | Metallic bodies that were the cores of differentiated bodies are sources of
iron meteorites and are considered to have formed early in the terrestrial
planet region before migrating to the main asteroid belt. Surface temperatures
and mutual collision velocities differ between the terrestrial planet region
and the main ... | 2103.03128v2 |
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