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low-mass x-ray binaries (lmxbs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. it is challenging to unambiguously determine whether an lmxb hosts a black hole or a neutron star. in the last few decades, multiple observational works have trie... | a machine-learning approach for classifying low-mass x-ray binaries based on their compact object nature |
we present a simple but informative online tool to visualize the multiwavelength (mw) properties of ≈2700 x-ray sources from chandra source catalog version 2.0 with literature verified classifications. here we describe the catalogs that we used to collect the classifications and extract the mw properties of these sourc... | visualizing multiwavelength properties of classified x-ray sources from chandra source catalog |
grb 190114c represents a breakthrough for the physics of gamma-ray bursts (grbs), being the first grb with delayed emission above 300 gev, as reported by magic. we present in this paper the sub-mev/mev data of the prompt and early afterglow emissions of grb 190114c, as detected by agile and konus-wind, in the 20 kev-10... | agile and konus-wind observations of grb 190114c: the remarkable prompt and early afterglow phases |
two custom-made in0.5ga0.5p p+-i-n+ circular mesa spectroscopic x-ray photodiodes with different diameters (200 μm and 400 μm) and a 5 μm i layer have been characterized for their response to x-ray photons within the energy range 4.95 kev to 21.17 kev. the photodiodes, operating uncooled at 30 °c, were coupled, in turn... | energy response characterization of ingap x-ray detectors |
the association of gw170817 with grb170817a proved that electromagnetic counterparts of gravitational wave events are the key to deeply understand the physics of ns-ns merges. upgrades of the existing gw antennas and the construction of new ones will allow to increase sensitivity down to several hundred mpc vastly incr... | timing techniques applied to distributed modular high-energy astronomy: the h.e.r.m.e.s. project |
relativistic reflection features in the x-ray spectra of black hole binaries and active galactic nuclei originate from illumination of the inner part of the accretion disc by a hot corona. in the presence of high quality data and with the correct astrophysical model, x-ray reflection spectroscopy can be quite a powerfu... | impact of the reflection model on the estimate of the properties of accreting black holes |
chandra x-ray observations of kepler's supernova remnant indicate the existence of a high-speed fe-rich ejecta structure in the southwestern region. we report strong k-shell emission from fe-peak elements (cr, mn, fe, ni), as well as ca, in this fe-rich structure, implying that those elements could be produced in the i... | a nucleosynthetic origin for the southwestern fe-rich structure in kepler's supernova remnant |
one aspect of the quantum nature of spacetime is its “foaminess” at very small scales. many models for spacetime foam are defined by the accumulation power α, which parameterizes the rate at which planck-scale spatial uncertainties (and the phase shifts they produce) may accumulate over large path lengths. here α is de... | new constraints on quantum gravity from x-ray and gamma-ray observations |
the hard x-ray modulation telescope (hxmt or also dubbed as insight-hxmt) is china's first astronomical satellite. it was launched on 15th june 2017 in jiuquan, china and is currently in service smoothly. it was designed to perform pointing, scanning and gamma-ray burst (grb) observations and, based on the direct demod... | the insight-hxmt mission and its recent progresses |
there has been a growing request from the x-ray astronomy community for a quantitative estimate of systematic uncertainties originating from the atomic data used in plasma codes. though there have been several studies looking into atomic data uncertainties using theoretical calculations, in general, there is no commonl... | x-ray spectra of the fe-l complex. iii. systematic uncertainties in atomic data |
soft x-ray emissions from solar wind charge exchange (swcx) are applied in a recently developed approach to study the magnetosphere using panoramic soft x-ray imaging. this study represents the first attempt to distinguish magnetospheric swcx emissions observed by xmm-newton during the impact of an interplanetary coron... | solar wind charge exchange soft x-ray emissions in the magnetosphere during an interplanetary coronal mass ejection compared to its driven sheath |
the existence of excess absorption in the x-ray spectra of grbs is well known, but the primary location of the absorbing material is still uncertain. to gain more knowledge about this, we have performed a time-resolved analysis of the x-ray spectra of 199 grbs observed by the swift x-ray telescope, searching for eviden... | investigating time variability of x-ray absorption in swift grbs |
this program is part of quest (quasar/ulirg evolutionary study) and seeks to examine the gaseous environments of z ≲ 0.3 quasars and ulirgs as a function of host galaxy properties and age across the merger sequence from ulirgs to quasars. this first paper in the series focuses on 33 quasars from the quest sample and on... | galactic winds across the gas-rich merger sequence. i. highly ionized n v and o vi outflows in the quest quasars |
present understandings of accretion disks based on x-ray observations are reviewed. the main focus is on observational properties of accretion disks around black holes in x-ray binaries and their phenomenological interpretations. since there are several excellent reviews on black hole binaries already, we here pick up ... | x-ray observations of accretion disks |
we review the history of astronomical x-ray polarimetry based on the author's perspective, beginning with early sounding-rocket experiments by robert novick at columbia university and his team, of which the author was a member. after describing various early techniques for measuring x-ray polarization, we discuss the p... | an overview of x-ray polarimetry of astronomical sources |
the focal plane of the x-ray integral field unit (x-ifu) for esa's athena x-ray observatory will consist of 4000 transition edge sensor (tes) x-ray microcalorimeters optimized for the energy range of 0.2 to 12 kev. the instrument will provide unprecedented spectral resolution of 2.5 ev at energies of up to 7 kev and wi... | transition-edge sensor pixel parameter design of the microcalorimeter array for the x-ray integral field unit on athena |
we report the detection of the mn-kα line in the sn-iib remnant, cassiopeia a. manganese (55mn after decay of 55co), a neutron-rich element, together with chromium (52cr after decay of 52fe), is mainly synthesized in core-collapse supernovae at the explosive incomplete si-burning regime. therefore, the mn/cr mass ratio... | a subsolar metallicity progenitor for cassiopeia a, the remnant of a type iib supernova |
this work is the continuation of our preceding work where we have shown that regular bardeen black hole surrounded by perfect fluid dark matter (pfdm) can be an alternative solution to explain the radiative efficiency of the astronomical source a0620-00. here we expand the number of x-ray sources containing black hole ... | regular black hole solution in pfdm environment to explain the radiative efficiency of black hole candidates |
we show how observations of gravitational waves from binary neutron star (bns) mergers over the next few years can be combined with insights from nuclear physics to obtain useful constraints on the equation of state (eos) of dense matter, in particular, constraining the neutron-matter eos to within 20% between one and ... | constraining the neutron-matter equation of state with gravitational waves |
space telescopes for solar hard x-ray imaging provide observations made of sampled fourier components of the incoming photon flux. the aim of this study is to design an image reconstruction method relying on enhanced visibility interpolation in the fourier domain. the interpolation-based method is applied to synthetic ... | visibility interpolation in solar hard x-ray imaging: application to rhessi and stix |
outflows are common in many astrophysical systems. in the two component advective flow (tcaf) paradigm, which is essentially a generalized bondi flow including rotation, viscosity, and cooling effects, the outflow originates in the hot, puffed up, post-shock region at the inner edge of the accretion disk. we consider t... | spectral signature of mass outflow in the two component advective flow paradigm |
by characterizing the contribution of stray light to large data sets from the cxb measurement x-ray observatory collected over 2012-2017, we report a measurement of the cosmic x-ray background (cxb) in the 3-20 kev energy range. these data represent ~20% sky coverage while avoiding galactic ridge x-ray emission and are... | measuring the cosmic x-ray background in 3-20 kev with stray light from nustar |
through several articles we have developed a model for dark matter as consisting of bubbles of a new (speculated) type of vacuum, starting from cm-sized pearls or balls down to atomic size ones and now we believe they have nanometer sizes. in the latest development of our model we have the bubbles of the new vacuum imb... | nano meter size dirty dark matter pearls, electron-signal, imp or sidm, not wimp |
we present an updated version of lightning, a galaxy spectral energy distribution (sed) fitting code that can model x-ray to submillimeter observations. the models in lightning include the options to contain contributions from stellar populations, dust attenuation and emission, and active galactic nuclei (agns). x-ray ... | lightning: an x-ray to submillimeter galaxy sed-fitting code with physically motivated stellar, dust, and agn models |
solar flares are known to release a large amount of energy into accelerating electrons. studying small timescale (≤2s) fluctuations in nonthermal x-ray flux offers the opportunity to probe the nature of those acceleration mechanisms. by comparing the durations, differences in timing between energy bands, and the period... | subsecond spikes in fermi gbm x-ray flux as a probe for solar flare particle acceleration |
the rosat x-ray background tool (sxrbg) calculates the average x-ray background count rate and statistical uncertainty in each of the six standard bands of the rosat all-sky survey (rass) diffuse background maps (r1, r2, r4, r5, r6, r7) for a specified astronomical position and a search region consisting of either a ci... | sxrbg: rosat x-ray background tool |
astrosat/uvit carries two gratings in the fuv channel and a single grating in the nuv channel. these gratings are useful for low resolution, slitless spectroscopy in the far and near uv bands of a variety of cosmic sources such as hot stars, interacting binaries, active galactic nuclei, etc. we present calibration of t... | calibration of astrosat/uvit gratings and spectral responses |
aims: we analyse the properties of the host galaxies of a [nev]-selected sample to investigate whether and how they are affected by the agn.methods: we have selected a sample of galaxies at 0.62 < z < 1.2 from the vimos public extragalactic redshift survey (vipers) and divided it in blue cloud galaxies, red passi... | the vimos public extragalactic redshift survey (vipers). agn feedback in [nev] emitters |
ultraluminous x-ray sources (ulxs) are a class of accreting compact objects with x-ray luminosities above 1039 erg s-1. the ulx population counts several hundred objects but only a fraction are well studied. here we present a detailed analysis of all ulxs hosted in the galaxy ngc 7456. it was observed in x-rays only on... | the ultraluminous x-ray sources population of the galaxy ngc 7456 |
the scientific challenges still open in hard x-rays and γ-rays astronomy require the development of new instrumentation able to overcome the sensitivity limits of the present one. among the technologies currently under study to cover the energy range between several tens of kev and one mev, the development of telescope... | a czt 3d imaging spectrometer prototype with digital readout for high energy astronomy |
we have been developing silicon-on-insulator pixel sensors, "xrpixs," for future x-ray astronomy satellites. xrpixs are equipped with a function of "event-driven readout," with which we can read out only hit pixels by trigger signals and hence realize good time resolution reaching ∼ 10 μs . the current version of xrpix... | reduction of cross-talks between circuit and sensor layer in the kyoto's x-ray astronomy soi pixel sensors with double-soi wafer |
the analysis of astronomical images is a non-trivial task. the d3po algorithm addresses the inference problem of denoising, deconvolving, and decomposing photon observations. its primary goal is the simultaneous but individual reconstruction of the diffuse and point-like photon flux given a single photon count image, w... | denoising, deconvolving, and decomposing photon observations. derivation of the d3po algorithm |
we present hitomi observations of n 132 d, a young, x-ray bright, o-rich core-collapse supernova remnant in the large magellanic cloud (lmc). despite a very short observation of only 3.7 ks, the soft x-ray spectrometer (sxs) easily detects the line complexes of highly ionized s k and fe k with 16-17 counts in each. the... | hitomi observations of the lmc snr n 132 d: highly redshifted x-ray emission from iron ejecta |
grailquest (gamma ray astronomy international laboratory for quantum exploration of space-time) is a mission concept based on a constellation (hundreds/thousands) of nano/micro/small-satellites in low (or near) earth orbits. each satellite hosts a non-collimated array of scintillator crystals coupled with silicon drift... | esa voyage 2050 white paper -- grailquest: hunting for atoms of space and time hidden in the wrinkle of space-time |
this paper presents a data processing algorithm with machine learning for polarization extraction and event selection applied to photoelectron track images taken with x-ray polarimeters. the method uses a convolutional neural network (cnn) classification to predict the azimuthal angle and 2-d position of the initial ph... | a convolutional neural network approach for reconstructing polarization information of photoelectric x-ray polarimeters |
we describe a process for cross-calibrating the effective areas of x-ray telescopes that observe common targets. the targets are not assumed to be "standard candles" in the classic sense, in that we assume that the source fluxes have well-defined, but a priori unknown values. using a technique developed by chen et al. ... | concordance: in-flight calibration of x-ray telescopes without absolute references |
the crab nebula is used by many instruments as a calibration source, in particular at high energy, where it is one of the brightest celestial objects. the spectrometer integral spi (20 kev-8 mev), in operation since 2002 october, offers a large data set dedicated to this source, with regular campaigns planned twice per... | 2003-2019 monitoring of the crab emission through integral spi, or vice versa |
astro-h was an x-ray astronomy satellite that the japan aerospace exploration agency (jaxa) developed to study the evolution of the universe and physical phenomena yet to be discovered. the primary scientific instrument of astro-h was the soft x-ray spectrometer (sxs). its detectors were to be cooled to 50 m k using a ... | in-orbit performance of a helium dewar for the soft x-ray spectrometer onboard astro-h |
astro-rivelatore gamma a immagini leggero (agile) is a space mission launched in 2007 to study x-ray and gamma-ray astronomy. the agile team developed real-time analysis pipelines to detect transient phenomena such as gamma-ray bursts (grbs) and react to external science alerts received by other facilities. the agile a... | a deep-learning anomaly-detection method to identify gamma-ray bursts in the ratemeters of the agile anticoincidence system |
a 3-stage adiabatic demagnetization refrigerator (adr) (shirron et al., 2012) is used on the soft x-ray spectrometer instrument (mitsuda et al., 2010) on astro-h (takahashi et al., 2010) [3] to cool a 6 × 6 array of x-ray microcalorimeters to 50 mk. the adr is supported by a cryogenic system (fujimoto et al., 2010) con... | operating modes and cooling capabilities of the 3-stage adr developed for the soft-x-ray spectrometer instrument on astro-h |
the magellanic stream and the leading arm form a massive, filamentary system of gas clouds surrounding the large and small magellanic clouds. here we present a new component-level analysis of their ultraviolet (uv) kinematic properties using a sample of 31 sightlines through the magellanic system observed with the hubb... | kinematics of the magellanic stream and implications for its ionization |
einstein's theory of general relativity was proposed over 100 years ago and has successfully passed a large number of observational tests in the weak field regime. however, the strong field regime is largely unexplored, and there are many modified and alternative theories that have the same predictions as einstein's gr... | relxill_nk: a relativistic reflection model for testing einstein's gravity |
x-ray imaging and spectroscopy mission (xrism) is an x-ray astronomical mission led by the japan aerospace exploration agency (jaxa) and national aeronautics and space administration (nasa), with collaboration from the european space agency (esa) and other international participants, that is planned for launch in 2022 ... | detailed design of the science operations for the xrism mission |
wr 25 is a colliding-wind binary star system comprising a very massive o2.5if*/wn6 primary and an o-star secondary in an eccentric orbit with a 208 day period. these hot stars have strong, highly supersonic winds that interact to form a bright x-ray source from wind-collision shocks whose conditions change with stellar... | the colliding winds of wr 25 in high-resolution x-rays |
the solar atmosphere is filled with clusters of hot small-scale loops commonly known as coronal bright points (cbps). these ubiquitous structures stand out in the sun by their strong x-ray and/or extreme-ultraviolet (euv) emission for hours to days, which makes them a crucial piece when solving the solar coronal heatin... | deciphering solar coronal heating: energizing small-scale loops through surface convection |
the study of the elusive hot component (t ≳ 107 k) of the milky way circumgalactic medium (cgm) is a novel topic for understanding galactic formation and evolution. in this work, we use the stacking technique through 46 lines of sight with chandra acis-s hetg totaling over 10 ms of exposure time and nine lines of sight... | detection of a supervirial hot component in the milky way circumgalactic medium along multiple sight lines by using the stacking technique |
we assess galactic dark matter (dm) sensitivities to photons from annihilation and decay using the spatial and kinematic information determined by state-of-the-art simulations in the latte suite of feedback in realistic environments (fire-2). for kinematic information, we study the energy shift pattern of dm narrow emi... | near to long-term forecasts in x-ray and gamma-ray bands: are we entering the era of dark matter astronomy? |
the binary neutron star merger gw170817 is the first and only astronomical object with a joint detection of gravitational waves and electromagnetic radiation. here we report the results from deep chandra x-ray observations of gw170817 at δt ∼ 940 days post merger. we find evidence for x-ray emission with flux fx = $({2... | x-ray emission from gw170817 ∼2.5 years after the merger |
we report on the discovery of 41 new pulsating sources in the data of the chandra advanced ccd imaging spectrometer, which is sensitive to x-ray photons in the 0.3-10 kev band. the archival data of the first 15 yr of chandra observations were retrieved and analysed by means of fast fourier transforms, employing a peak-... | the chandra acis timing survey project: glimpsing a sample of faint x-ray pulsators |
we perform detailed spectroscopy of the x-ray-brightest supernova remnant in the large magellanic cloud (lmc), n132d, using chandra archival observations. by analyzing the spectra of the entire well-defined rim, we determine the mean abundances for o, ne, mg, si, s, and fe for the local lmc environment. we find evidenc... | spatially resolved chandra spectroscopy of the large magellanic cloud supernova remnant n132d |
we assess galactic dark matter (dm) sensitivities to photons from annihilation and decay using the spatial and kinematic information determined by state-of-the-art simulations in the latte suite of feedback in realistic environments (fire-2). for kinematic information, we study the energy shift pattern of dm narrow emi... | entering the era of dark matter astronomy? near to long-term forecasts in x-ray and gamma-ray bands |
we develop the power spectral density (psd) model to explain the nature of the x-ray variability in iras 13224-3809, including the full effects of the x-ray reverberation due to the lamppost source. we utilize 16 xmm-newton observations individually as well as group them into three different luminosity bins: low, mediu... | mapping the x-ray corona evolution of iras 13224-3809 with the power spectral density |
there are currently many large-field surveys that are operational and are being planned including the powerful vera c. rubin observatory legacy survey of space and time. these surveys will increase the number and diversity of transients dramatically. however, for some transients, like supernovae (sne), we can gain more... | supernova shock breakout/emergence detection predictions for a wide-field x-ray survey |
the geologic time scale for the cenozoic era has been notably improved over the last decades by virtue of integrated stratigraphy, combining high-resolution astrochronologies, biostratigraphy and magnetostratigraphy with high-precision radioisotopic dates. however, the middle eocene remains a weak link. the so-called "... | a lower to middle eocene astrochronology for the mentelle basin (australia) and its implications for the geologic time scale |
a detailed biostratigraphic, chemostratigraphic, and chronostratigraphic study was carried out in the south‑western margin of the neo‑tethys ocean (tunisia) covering the eocene‑oligocene interval to report potential paleoenvironmental and paleoclimatic changes associated with the growth of the antarctic ice sheet (ais)... | the eocene‑oligocene transition in the south‑western neo‑tethys (tunisia): astronomical calibration and paleoenvironmental changes |
we are developing arrays of position-sensitive microcalorimeters for future x-ray astronomy applications. these position-sensitive devices commonly referred to as hydras consist of multiple x-ray absorbers, each with a different thermal coupling to a single-transition-edge sensor microcalorimeter. their development is ... | multiabsorber transition-edge sensors for x-ray astronomy |
svom (space-based multi-band astronomical variable objects monitor) is an international cooperation project led by the chinese national space agency (cnsa) and the centre national d'etudes spatiales of france (cnes). svom focuses on the detection of gamma-ray bursts (grbs). it is developed by the chinese academy of sci... | svom: a joint gamma-ray burst detection mission |
being a part of the petroliferous linqing depression, the dongpu sag is located in the sw part of the bohai bay basin, eastern china, and is rich in oil and gas. as new discoveries of conventional, structural, and stratigraphic plays of oil and gas have been gradually diminished in the sag, there is an urgent requireme... | astronomical time scale of a middle eocene lacustrine sequence from the dongpu sag, bohai bay basin, eastern china |
a range of astronomical data indicates that ancient supernovae created the galactic environment of the sun and sculpted the physical properties of the interstellar medium near the heliosphere. in this paper, we review the characteristics of the local interstellar medium that have been affected by supernovae. the kinema... | effect of supernovae on the local interstellar material |
we present evidence of diffuse, non-thermal x-ray emission from the superbubble 30 doradus c (30 dor c) using hard x-ray images and spectra from nustar observations. for this analysis, we utilize data from a 200 ks targeted observation of 30 dor c as well as 2.8 ms of serendipitous off-axis observations from the monito... | evidence of particle acceleration in the superbubble 30 doradus c with nustar |
we report chandra observations of the highly asymmetric core-collapse supernova remnant g350.1-0.3. we document expansion over 9 yr away from the roughly stationary central compact object, with sky-plane velocities up to 5000 d4.5 km s-1 (d4.5 is the distance in units of 4.5 kpc), redshifts ranging from 900 to 2600 km ... | expansion and age of the supernova remnant g350.1-0.3: high-velocity iron ejecta from a core-collapse event |
in astronomy and cosmology significant effort is devoted to characterizing and understanding spatial cross-correlations between points - e.g galaxy positions, high energy neutrino arrival directions, x-ray and agn sources, and continuous fields - e.g. weak lensing meiand cosmic microwave background maps. recently, we i... | tracer-field cross-correlations with k-nearest neighbour distributions |
gamma-ray flares of blazars may be accompanied by high-energy neutrinos due to interactions of high-energy cosmic rays in the jet with photons, as suggested by the detection of the high-energy neutrino icecube-170922a during a major gamma-ray flare from blazar txs 0506+056 at the ~3σ significance level. in this work, w... | flare duty cycle of gamma-ray blazars and implications for high-energy neutrino emission |
the kepler space telescope and transiting exoplanet survey satellite unveiled that sun-like stars frequently host exoplanets. these exoplanets are subject to fluxes of ionizing radiation in the form of x-ray and extreme-ultraviolet (euv) radiation that may cause changes in their atmospheric dynamics and chemistry. whil... | reconstructing the xuv spectra of active sun-like stars using solar scaling relations with magnetic flux |
improved observational constraints on the orbital parameters of the low-mass x-ray binary scorpius x-1 were recently published in killestein et al. in the process, errors were corrected in previous orbital ephemerides, which have been used in searches for continuous gravitational waves from sco x-1 using data from the ... | search for gravitational waves from scorpius x-1 in ligo o3 data with corrected orbital ephemeris |
we have performed a systematic study of the rotational, orbital, and x-ray properties of millisecond pulsars (msps) in globular clusters (gcs) and compared their nature with those of the msps in the galactic field (gf). we found that gc msps generally rotate slower than their counterparts in the gf. different from the ... | a comparison of millisecond pulsar populations between globular clusters and the galactic field |
we have collected a new deep chandra x-ray observatory exposure of psr b2224+65 and the "guitar nebula," mapping the complex x-ray structure. this is accompanied by a new hubble space telescope (hst) hα image of the head of the guitar. comparing the hst and chandra structures in four epochs over 25 yr, we constrain the... | a quarter century of guitar nebula/filament evolution |
microcalorimeters have demonstrated success in delivering high spectral resolution, and have paved the path to revolutionary new science possibilities in the coming decade of x-ray astronomy. there are several research areas in compact object science that can only be addressed with energy resolution delta(e)<~5 ev a... | accretion physics at high x-ray spectral resolution: new frontiers and game-changing science |
extraterrestrial gamma-ray astronomy is now a source of a new knowledge in the fields of astrophysics, cosmic-ray physics, and the nature of dark matter. the next absolutely necessary step in the development of extraterrestrial high-energy gamma-ray astronomy is the improvement of the physical and technical characteris... | gamma-400 project |
we have been developing monolithic active pixel sensors series, named ``xrpix'', based on the silicon-on-insulator (soi) pixel technology, for future x-ray astronomical satellites. the xrpix series offers high coincidence time resolution (~ 1 μs), superior readout time (~ 10 μs), and a wide energy range (0.5-40 kev) . ... | improvement of spectroscopic performance using a charge-sensitive amplifier circuit for an x-ray astronomical soi pixel detector |
the andromeda galaxy (m31) has been observed with the ultraviolet imaging telescope (uvit) instrument onboard the astrosat observatory. the m31 sky area was covered with 19 fields, in multiple uv filters per field, over the period of 2017 to 2019. the entire galaxy was observed in the fuv f148w filter, and more than ha... | new results from the uvit survey of the andromeda galaxy |
the field of artificial intelligence based image enhancement has been rapidly evolving over the last few years and is able to produce impressive results on non-astronomical images. in this work, we present the first application of machine learning based super-resolution (sr) and de-noising (dn) to enhance x-ray images ... | deep learning-based super-resolution and de-noising for xmm-newton images |
the x-ray silicon-on-insulator (soi) pixel sensor named xrpix has been developed for the future x-ray astronomical satellite force. xrpix is capable of a wide-band x-ray imaging spectroscopy from below 1 kev to a few tens of kev with a good timing resolution of a few tens of $\mu$s. however, it had a major issue with i... | radiation-induced degradation mechanism of x-ray soi pixel sensors with pinned depleted diode structure |
the swift deep galactic plane survey (dgps) is a swift key project consisting of 380 tiled pointings covering ~40 deg2 of the galactic plane between longitude 10 < ∣l∣ < 30 deg and latitude ∣b∣ < 0.5 deg. each pointing has a 5 ks exposure, yielding a total of 1.9 ms spread across the entire survey footprint. p... | the swift deep galactic plane survey (dgps) phase i catalog |
warm absorber spectra contain bound-bound and bound-free absorption features seen in the x-ray and uv spectra from many active galactic nuclei. the widths and centroid energies of these features indicate they occur in outflowing gas, and the outflow can affect the gas within the host galaxy. thus, the warm absorber mas... | time-dependent photoionization modeling of warm absorbers in active galactic nuclei |
between 2011 march and 2014 august swift responded to 20 triggers from the icecube neutrino observatory, observing the icecube 50 per cent confidence error circle in x-rays, typically within 5 h of the trigger. no confirmed counterpart has been detected. we describe the swift follow-up strategy and data analysis and pr... | swift follow-up of icecube triggers, and implications for the advanced-ligo era |
we report on xmm-newton and nustar x-ray observations of the prototypical polar, am herculis, supported by ground-based photometry and spectroscopy, all obtained in high accretion states. in 2005, am herculis was in its regular mode of accretion, showing a self-eclipse of the main accreting pole. x-ray emission during ... | the various accretion modes of am herculis: clues from multi-wavelength observations in high accretion states |
polarlight is the first dedicated soft x-ray polarimeter in space since the 1970s and is attempting to reopen this long-awaited window in astronomy, explain principal investigator hua feng and ronaldo bellazzini. | the x-ray polarimetry window reopens |
the galactic microquasar grs 1915+105 shows rich variability that is categorized into different classes. in this paper, we report the temporal and spectral analysis of grs 1915+105 to study the properties of the accretion flow when the light curve shows θ class variability. for this purpose, we use the large area x-ray... | accretion flow properties of grs 1915+105 during its θ class using astrosat data |
the physical origin of the overionized recombining plasmas (rps) in supernova remnants (snrs) has been attracting attention because its understanding provides new insight into snr evolution. however, the process of the overionization, although it has been discussed in some rp-snrs, is not yet fully understood. here, we... | investigation of the physical origin of overionized recombining plasma in the supernova remnant ic 443 with xmm-newton |
recently selected by nasa as the next small explorer (smex) mission for a launch in 2021, the imaging x-ray polarimetry explorer (ixpe) marks the renaissance of x-ray polarimetry, with the prospect of measuring linear polarization from tens of astronomical x-ray sources. ixpe will expand the x-ray view of the universe ... | the imaging x-ray polarimetry explorer (ixpe) |
athena is the l2 mission selected by esa to pursue the science theme "hot and energetic universe." one of the two focal plane instruments is the x-ray integral field unit, an array of tes microcalorimeters operated at t < 100 mk. to allow the x-ray photons focused by the telescope to reach the detector, windows have... | thermal filters for the athena x-ifu: ongoing activities toward the conceptual design |
in this paper, we propose a new mechanism that could explain the survival of hydrogen atmospheres on some hot super-earths. we argue that on close-orbiting tidally locked super-earths, the tidal forces, together with the orbital and rotational centrifugal forces, can partially confine the atmosphere on the nightside. a... | hot super-earths with hydrogen atmospheres: a model explaining their paradoxical existence |
we present an initial study of the mass and evolutionary state of a massive and distant cluster, rcs2 j232727.6-020437. this cluster, at z = 0.6986, is the richest cluster discovered in the rcs2 project. the mass measurements presented in this paper are derived from all possible mass proxies: x-ray measurements, weak-l... | a multi-wavelength mass analysis of rcs2 j232727.6-020437, a ∼3 × 1015 m⊙ galaxy cluster at z = 0.7 |
neutron stars are thought to be born rapidly rotating and then exhibit a phase of rotation-powered pulsations as they slow down to 1-10 s periods. the significant population of millisecond pulsars observed in our galaxy is explained by the recycling concept: during an epoch of accretion from a donor star in a binary sy... | the slowest spinning x-ray pulsar in an extragalactic globular cluster |
we report our measurements of the bulk radial velocity from a sample of small, metal-rich ejecta knots in kepler's supernova remnant (snr). we measure the doppler shift of the he-like si kα line-center energy in the spectra of these knots based on our chandra high-energy transmission grating spectrometer observation to... | an ejecta kinematics study of kepler's supernova remnant with high-resolution chandra hetg spectroscopy |
insight-hxmt, the first x-ray astronomical satellite in china, aims to reveal new sources in the galaxy and to study fundamental physics of x-ray binaries from 1 to 250 kev. it has three collimated telescopes, the high energy x-ray telescope (he), the medium energy x-ray telescope (me), and the low energy x-ray telesco... | comparison of simulated backgrounds with in-orbit observations for he, me, and le onboard insight-hxmt |
predictions for the ability of 21 cm interferometric experiments to discriminate epoch of reionization (eor) signal models are typically limited by the simplicity of data models, whereby foreground signals and characteristics of the instrument are often simplified or neglected. to move toward more realistic scenarios, ... | the impact of realistic foreground and instrument models on 21 cm epoch of reionization experiments |
we present xmm-newton observations of n132d, the x-ray brightest supernova remnant in the large magellanic cloud, using the reflection grating spectrometer (rgs), which enables high-resolution spectroscopy in the soft x-ray band. a dozen emission lines from l-shell transitions of si, s, ar, ca, and fe at intermediate c... | plasma diagnostics of the supernova remnant n132d using deep xmm-newton observations with the reflection grating spectrometer |
context. during more than 17 years of operation in space, the international gamma-ray astrophysics laboratory (integral) telescope has accumulated a large data set that contains records of hard x-ray and soft γ-ray astronomical sources. these data can be reused in the context of multi-wavelength or multi-messenger stud... | online data analysis system of the integral telescope |
in 2016-17, the galactic transient black hole candidate grs 1716-249 exhibited an outburst event after a long quiescence period of almost 23 years. the source remained in the outbursting phase for almost 9 months. we study the spectral and temporal properties of the source during this outburst using archival data from ... | accretion flow properties of grs 1716-249 during its 2016-17 `failed' outburst |
the latest high altitude water cherenkov (hawc) point-like source catalog up to 56 tev reported the detection of two sources in the region of the galactic plane at galactic longitude 52° < ℓ < 55°, 3hwc j1930+188 and 3hwc j1928+178. the first one is associated with a known tev source, the supernova remnant snr g0... | detailed analysis of the tev γ-ray sources 3hwc j1928+178, 3hwc j1930+188, and the new source hawc j1932+192 |
4u 1957+11 is a black hole candidate system that has been in a soft x-ray spectral state since its discovery. we present analyses of recent joint nicer and nustar spectra, which are extremely well described by a highly inclined disk accreting into a near maximally spinning black hole. owing to the broad x-ray coverage ... | nicer/nustar characterization of 4u 1957+11: a near maximally spinning black hole potentially in the mass gap |
electron compton scattering of target photons into the gamma-ray energy band (inverse compton scattering; ic) is commonly expected to dominate the very high energy (vhe) spectra in gamma-ray bursts (grbs) especially during the afterglow phase. for sufficiently large center-of-mass energies in these collisions, the effe... | the formation of hard very high energy spectra from gamma-ray burst afterglows via two-zone synchrotron self-compton emission |
we report measurements of electron-impact excitation cross sections for the strong k-shell n = 2 → 1 transitions in s xv, using the llnl ebit-i electron beam ion trap, two crystal spectrometers, and the ebit calorimeter spectrometer. the cross sections are determined by direct normalization to the well-known cross sect... | high-resolution laboratory measurements of k-shell x-ray line polarization and excitation cross sections in helium-like s xv ions |
an x-ray pulsar is a remnant of massive star evolution, collapse, and supernova explosions. it has an extremely stable spin cycle and is known as the most accurate astronomical clock in the natural world. it presents high-precision navigational information, such as the location, speed, time, and attitude, which are use... | 314 mm2 hexagonal double-sided spiral silicon drift detector for soft x-ray detection based on ultra-pure high resistance silicon |
context. ngc 6366 is a metal-rich globular cluster that is relatively unstudied. it is a kinematically interesting cluster, reported as belonging to the slowly rotating halo system, which is unusual given its metallicity and spatial location in the galaxy.aims: the purpose of this research is to determine the relative ... | proper motions and membership probabilities of stars in the region of globular cluster ngc 6366 |
the x-ray astronomy and observational cosmology (xoc) group at stanford university, in collaboration with the massachusetts institute of technology (mit) and mit lincoln laboratory (mit-ll), is developing next generation x-ray detector and readout technologies. specifically, the xoc group is developing a fast, low nois... | x-ray speed reading with the mcrc: a low noise ccd readout asic enabling readout speeds of 5 mpixel/s/channel |
we present the results of a detailed investigation into the physical conditions in interstellar material interacting with the supernova remnant (snr) ic 443. our analysis is based on a comprehensive examination of high-resolution far-ultraviolet spectra obtained with the space telescope imaging spectrograph onboard the... | physical conditions in shocked interstellar gas interacting with the supernova remnant ic 443 |
polarlight is a compact soft x-ray polarimeter onboard a cubesat, which was launched into a low-earth orbit on october 29, 2018. in march 2019, polarlight started full operation, and since then, regular observations with the crab nebula, sco x-1, and background regions have been conducted. here we report the operation,... | in-orbit operation and performance of the cubesat soft x-ray polarimeter polarlight |
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