512 citations · 6.9k across the 194 of their papers we have counts for
140 papers · 1 filter
The Geometry of Ultra-Fast Outflows Probed by Soft X-ray Variability in PDS 456
Riki Sato, Kouichi Hagino, Toshiya Iwata +20
Constraining the location and geometry of ultra-fast outflows (UFOs) is essential for identifying where they are launched and how they are accelerated. We investigate the soft X-ra…
The Complete Catalog of Gamma-Ray Transients Observed by GRBAlpha & VZLUSAT-2 CubeSat Missions
Marianna Dafcikova, Jakub Ripa, Andras Pal +45
We present the largest sample of gamma-ray transients observed by any CubeSat mission so far. Observations were acquired by a 1U CubeSat GRBAlpha, the smallest astrophysical space…
The line modulations of H-like Fe, Ca, Ar, and S observed with /Resolve in Cyg X-3
Tomohiro Hakamata, Hirokazu Odaka, Ryota Tomaru +13
Cygnus X-3, hosting a Wolf-Rayet (WR) star whose dense wind produces various spectral lines due to photoionization by X-rays from a compact object, provides an ideal laboratory for…
A XRISM Study of Highly Ionized Iron Emission Lines from the Low-Eddington-ratio AGN in NGC 7213
Kaito Murakami, Taiki Kawamuro, Ryota Tomaru +10
We present an analysis of XRISM and NuSTAR data obtained for the nearby low-Eddington active galactic nucleus NGC 7213. Our goal is to examine whether its He-like and H-like iron e…
Accurate Determination of Chemical Abundances near a Supermassive Black Hole
The XRISM collaboration
The metal abundances in galactic nuclei carry key information on the history of star formation and mass transfer in central regions of galaxies. X-ray fluorescence analysis is a un…
High Spectral Resolution X-ray Observations of the Evolved Supermassive Stellar Binary System Carinae - Iron K Band Profile Revealed with XRISM
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +138
The supermassive binary system, Carinae, is experiencing enormous wind-driven mass loss at a rate unparalleled in the rest of the Galaxy. Their wind-wind collision (WWC) contin…
Unification Model of Active Galactic Nuclei by Photoionization Equilibrium Calculation Based on Radiative Hydrodynamic Simulations
Atsushi Tanimoto, Keiichi Wada, Yuki Kudoh +3
To investigate the origin of the dependence of the covering factor on the Eddington ratio suggested by X-ray observations, we examined the angular distribution of HI and HII based…
GRBAlpha, VZLUSAT-2 and GRBBeta -- GRB observations with CubeSats
Jakub Ripa, Marianna Dafcikova, Andras Pal +49
Results from GRBAlpha, VZLUSAT-2 and GRBBeta CubeSats and their on-board gamma-ray detectors for monitoring transients are summarised in this article. GRBAlpha was a 1U CubeSat lau…
X-ray Analysis and Photon-transport Simulations of SMC X-1: A Warped-disc Origin of the Superorbital Modulation
Satoshi Takashima, Hirokazu Odaka, Ryota Tomaru +3
The luminous accreting pulsar SMC X-1 is an appropriate target to explore the accretion dynamics. SMC X-1 shows unique quasi-periodic flux variability of 40-65days known as sup…
Chlorine and Potassium Enrichment in the Cassiopeia A Supernova Remnant
XRISM collaboration
The elements in the universe are synthesized primarily in stars and supernovae, where nuclear fusion favors the production of even-Z elements. In contrast, odd-Z elements are less…
XRISM/Resolve reveals the complex iron structure of NGC 7213: Evidence for radial stratification between inner disk and broad-line region
E. Kammoun, T. Kawamuro, K. Murakami +48
We present the first high-resolution X-ray spectrum of NGC 7213 obtained with XRISM/Resolve, supported by simultaneous XMM-Newton, NuSTAR, and SOAR optical data. The XRISM spectrum…
Emission and Absorption Features of Magnetically Driven Disk Winds in Black Hole X-Ray Binaries
Atsushi Tanimoto, Keigo Fukumura, Shoji Ogawa +5
We investigate accretion disk winds commonly observed in galactic black hole (BH) X-ray binaries (XRB), which manifest as blueshifted absorption features in X-ray spectra. We model…
XRISM constraints on unidentified X-ray emission lines, including the 3.5 keV line, in the stacked spectrum of ten galaxy clusters
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +150
We stack 3.75 Megaseconds of early XRISM Resolve observations of ten galaxy clusters to search for unidentified spectral lines in the 2.5-15 keV band (rest frame), including t…
Stratified wind from a super-Eddington X-ray binary is slower than expected
XRISM collaboration, Marc Audard, Hisamitsu Awaki +132
Accretion discs in strong gravity ubiquitously produce winds, seen as blueshifted absorption lines in the X-ray band of both stellar mass X-ray binaries (black holes and neutron st…
XRISM/Resolve View of Abell 2319: Turbulence, Sloshing, and ICM Dynamics
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +132
We present results from XRISM/Resolve observations of the core of the galaxy cluster Abell 2319, focusing on its kinematic properties. The intracluster medium (ICM) exhibits temper…
The detection of high X-ray polarization from an accretion disc corona source and its modelling via Monte Carlo radiation transfer simulation
Ryota Tomaru, Chris Done, Hirokazu Odaka
We report a time averaged 2--8 keV X-ray polarization degree (PD) of ( detection) from the accretion-disc-corona (ADC) neutron-star system 2S 0921-630 (=V395 C…
Disentangling Multiple Gas Kinematic Drivers in the Perseus Galaxy Cluster
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +143
Galaxy clusters, the Universe's largest halo structures, are filled with 10-100 million degree X-ray-emitting gas. Their evolution is shaped by energetic processes such as feedback…
Unraveling the structure of the stratified ultra-fast outflows in PDS 456 with XRISM
Yerong Xu, Luigi C. Gallo, Kouichi Hagino +18
Multiple clumpy wind components () in the luminous quasar PDS 456 have recently been resolved by XRISM in the Fe-K band for the first time. In this paper, we i…
XRISM spectroscopy on orbital modulation of Fe Ly lines in Cygnus X-3
Daiki Miura, Hiroya Yamaguchi, Ralf Ballhausen +17
To understand physical processes such as mass transfer and binary evolution in X-ray binaries, the orbital parameters of the system are fundamental and crucial information. Cygnus…
X-Ray Radiative Transfer Calculation Based on a Physics-based Model of the Sub-parsec-scale Gases around an Active Galactic Nucleus and Its Application to NGC 3783
Atsushi Tanimoto, Keiichi Wada, Hirokazu Odaka +2
Although the X-ray spectra of Seyfert 1 galaxies exhibit absorption lines of He-like iron and H-like iron at blue-shifted velocities of approximately $500 \ \mathrm{km} \ \mathrm{s…
Structured ionized winds shooting out from a quasar at relativistic speeds
XRISM collaboration
Evidence indicates that supermassive black holes exist at the centers of most galaxies. Their mass correlates with the galactic bulge mass, suggesting a co-evolution with their hos…
The Moon as a Cosmic-Ray Spectrometer: Prospects for MeV Gamma-Ray Observations
Tatsuki Fujiwara, Ellis R. Owen, Yoshiyuki Inoue +10
The Moon is the closest celestial gamma-ray emitting object. Its gamma-ray emission arises from interactions between Galactic cosmic rays (CRs) and the lunar surface. While the lun…
XRISM forecast for the Coma cluster: stormy, with a steep power spectrum
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +142
The XRISM Resolve microcalorimeter array measured the velocities of hot intracluster gas at two positions in the Coma galaxy cluster: 3'x3' squares at the center and at 6' (170 kpc…
The nature of spectral variability of the accreting pulsar Centaurus X-3 unveiled by NuSTAR observation covering two orbital cycles
Tsubasa Tamba, Hirokazu Odaka, Atsushi Tanimoto +3
We conducted a NuSTAR observation on the X-ray pulsar Centaurus X-3, which covered two consecutive orbital cycles of the source, including two eclipse durations. We…