Publications (53)
Hitomi Observations of the LMC SNR N132D: Highly Redshifted X-ray Emission from Iron Ejecta
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
We present Hitomi observations of N132D, a young, X-ray bright, O-rich core-collapse supernova remnant in the Large Magellanic Cloud (LMC). Despite a very short observation of only…
Hitomi X-ray studies of Giant Radio Pulses from the Crab pulsar
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +201
To search for giant X-ray pulses correlated with the giant radio pulses (GRPs) from the Crab pulsar, we performed a simultaneous observation of the Crab pulsar with the X-ray satel…
Multiwavelength study of X-ray Luminous Clusters in the Hyper Suprime-Cam Subaru Strategic Program S16A field
Keita Miyaoka, Nobuhiro Okabe, Takao Kitaguchi +34
We present a joint X-ray, optical and weak-lensing analysis for X-ray luminous galaxy clusters selected from the MCXC (Meta-Catalog of X-Ray Detected Clusters of Galaxies) cluster…
Detection of polarized gamma-ray emission from the Crab nebula with Hitomi Soft Gamma-ray Detector
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
We present the results from the Hitomi Soft Gamma-ray Detector (SGD) observation of the Crab nebula. The main part of SGD is a Compton camera, which in addition to being a spectrom…
The ASTRO-H X-ray Astronomy Satellite
Tadayuki Takahashi, Kazuhisa Mitsuda, Richard Kelley +250
The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions developed by the Institute of Space and Astronautical Science (ISAS), with a planne…
Radiation tolerance of a diamond radiation detector for space use
Yoshiyuki Ando, Shutaro Ueda, Ryota Heibatake +13
We present a study of the radiation tolerance of two types of diamond radiation detectors for space use. We plan to launch a 3U-size CubeSat, KSAT3-X, developed by Kanazawa Univers…
Discovery of an Overlapping Cluster in Abell 1674 Field with Suzaku
Shota Inoue, Kiyoshi Hayashida, Hiroki Akamatsu +5
We present the results of a Suzaku observation of Abell 1674, an optically very rich (richness class 3) cluster cataloged as z = 0.1066. We discover the He-like Fe K-shell line fro…
Halo Concentration, Galaxy Red Fraction, and Gas Properties of Optically-defined Merging Clusters
Nobuhiro Okabe, Masamune Oguri, Hiroki Akamatsu +9
We present multi-wavelength studies of optically-defined merging clusters, based on the Hyper Suprime-Cam Subaru Strategic Program. Luminous red galaxies, tracing cluster mass dist…
Search for a Non-equilibrium Plasma in the Merging Galaxy Cluster Abell 754
Shota Inoue, Kiyoshi Hayashida, Shutaro Ueda +3
Abell 754 is a galaxy cluster in which an ongoing merger is evident on the plane of the sky, from the southeast to the northwest. We study the spatial variation of the X-ray spectr…
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…
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…
Glimpse of the highly obscured HMXB IGR J16318-4848 with Hitomi
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
We report a Hitomi observation of IGR J16318-4848, a high-mass X-ray binary system with an extremely strong absorption of N_H~10^{24} cm^{-2}. Previous X-ray studies revealed that…
Atomic data and spectral modeling constraints from high-resolution X-ray observations of the Perseus cluster with Hitomi
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +192
The Hitomi SXS spectrum of the Perseus cluster, with 5 eV resolution in the 2-9 keV band, offers an unprecedented benchmark of the atomic modeling and database for hot collis…
Hitomi X-ray Observation of the Pulsar Wind Nebula G21.50.9
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +194
We present results from the Hitomi X-ray observation of a young composite-type supernova remnant (SNR) G21.50.9, whose emission is dominated by the pulsar wind nebula (PWN) cont…
Discovery of Gas Bulk Motion in the Galaxy Cluster Abell 2256 with Suzaku
Takayuki Tamura, Kiyoshi Hayashida, Shutaro Ueda +1
The results from Suzaku observations of the galaxy cluster Abell2256 are presented. This cluster is a prototypical and well-studied merging system, exhibiting substructures both in…
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) conti…
Hitomi constraints on the 3.5 keV line in the Perseus galaxy cluster
Hitomi Collaboration, Felix A. Aharonian, Hiroki Akamatsu +215
High-resolution X-ray spectroscopy with Hitomi was expected to resolve the origin of the faint unidentified E=3.5 keV emission line reported in several low-resolution studies of va…
Comparing XRISM cluster velocity dispersions with predictions from cosmological simulations: are feedback models too ejective?
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +147
The dynamics of the intra-cluster medium (ICM), the hot plasma that fills galaxy clusters, are shaped by gravity-driven cluster mergers and feedback from supermassive black holes (…
Single event effect characterization of the mixed-signal ASIC developed for CCD camera in space use
Hiroshi Nakajima, Mari Fujikawa, Hideki Mori +10
We present the single event effect (SEE) tolerance of a mixed-signal application-specific integrated circuit (ASIC) developed for a charge-coupled device camera onboard a future X-…
Suzaku observations of the type 2 QSO in the central galaxy of the Phoenix cluster
Shutaro Ueda, Kiyoshi Hayashida, Naohisa Anabuki +3
We report the \Suzaku/XIS and HXD and \Chandra/ACIS-I results on the X-ray spectra of the Phoenix cluster at the redshift . The spectrum of the intracluster medium (ICM) i…
Systematic Perturbations of the Thermodynamic Properties in Cool Cores of HIFLUGCS Galaxy Clusters
Shutaro Ueda, Keiichi Umetsu, FanLam Ng +3
We present an ensemble X-ray analysis of systematic perturbations in the central hot gas properties for a sample of 28 nearby strong cool-core systems selected from the HIghest X-r…
Vigorous turbulence driven by quasar-mode feedback in a cluster core
Satoshi Yamada, Shutaro Ueda, Hirofumi Noda +9
Quasars are among the most luminous objects. They are powered by accretion onto supermassive black holes. They are thought to impact cosmological evolution primarily through energe…
Line-of-sight Elongation and Hydrostatic Mass Bias of the Frontier Fields Galaxy Cluster Abell 370
Keiichi Umetsu, Shutaro Ueda, Bau-Ching Hsieh +6
We present a detailed weak-lensing and X-ray study of the Frontier Fields galaxy cluster Abell 370, one of the most massive known lenses on the sky, using wide-field BRz Subaru/Spr…
Probable Detection of a Cooler Gas Component in the Perseus Cluster with XRISM
Julian Meunier, Brian R. McNamara, Aurora Simionescu +36
We present an analysis of the temperature structure of the Perseus cluster atmosphere using XRISM Resolve observations. The average temperature rises from 3.3 keV near the nucleus…
Embedded Spiral Patterns in the Cool Core of the Massive Cluster of Galaxies Abell 1835
Shutaro Ueda, Tetsu Kitayama, Tadayasu Dotani
We present the properties of intracluster medium (ICM) in the cool core of the massive cluster of galaxies Abell 1835 obtained with the data by - .…
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…
New Insights on 30 Dor B Revealed by High-Quality Multi-wavelength Observations
Wei-An Chen, Chuan-Jui Li, You-Hua Chu +4
The supernova remnant (SNR) 30 Dor B is associated with the \ion{H}{2} region ionized by the OB association LH99. The complex interstellar environment has made it difficult to stud…
X-ray study of the double source plane gravitational lens system Eye of Horus observed with XMM-Newton
Keigo Tanaka, Ayumi Tsuji, Hiroki Akamatsu +19
A double source plane (DSP) system is a precious probe for the density profile of distant galaxies and cosmological parameters. However, these measurements could be affected by the…
Suzaku Discovery of Fe K-Shell Line from the O-Rich SNR G292.0+1.8
Fumiyoshi Kamitsukasa, Katsuji Koyama, Hiroshi Tsunemi +7
We report the Suzaku/XIS results of the Galactic oxygen-rich supernova remnant (SNR), G292.0+1.8, a remnant of a core-collapse supernova. The X-ray spectrum of G292.0+1.8 consists…
Soft X-ray Imager aboard Hitomi (ASTRO-H)
Takaaki Tanaka, Hiroyuki Uchida, Hiroshi Nakajima +25
The Soft X-ray Imager (SXI) is an imaging spectrometer using charge-coupled devices (CCDs) aboard the Hitomi X-ray observatory. The SXI sensor has four CCDs with an imaging area si…
Chemical enrichment of the Perseus cluster core seen by XRISM/Resolve
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +143
The intracluster medium (ICM) is rich in chemical elements, produced by core-collapse (SNcc) and Type Ia supernovae (SNIa) over the last 12 Gyr. Whereas cluster outskirts are…
An azimuthally resolved study of sloshing cold fronts in three nearby galaxy clusters
I-Hsuan Li, Shutaro Ueda, I-Non Chiu +1
We present a detailed analysis of sloshing cold fronts in a sample of three nearby galaxy clusters (Abell 496, Abell 2029, and Abell 1644) observed with the Chandra X-ray Observato…
Temperature Structure in the Perseus Cluster Core Observed with Hitomi
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +192
The present paper investigates the temperature structure of the X-ray emitting plasma in the core of the Perseus cluster using the 1.8--20.0 keV data obtained with the Soft X-ray S…
Discovery of Radio Jets in Phoenix Galaxy Cluster Center
Takuya Akahori, Tetsu Kitayama, Shutaro Ueda +6
We report the results of the Australia Telescope Compact Array (ATCA) 15 mm observation of the Phoenix galaxy cluster possessing an extreme star-burst brightest cluster galaxy (BCG…
Hitomi Observation of Radio Galaxy NGC 1275: The First X-ray Microcalorimeter Spectroscopy of Fe-Kα Line Emission from an Active Galactic Nucleus
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +191
The origin of the narrow Fe-Kα fluorescence line at 6.4 keV from active galactic nuclei has long been under debate; some of the possible sites are the outer accretion disk, the br…
Measurements of resonant scattering in the Perseus cluster core with Hitomi SXS
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +192
Thanks to its high spectral resolution (~5 eV at 6 keV), the Soft X-ray Spectrometer (SXS) on board Hitomi enables us to measure the detailed structure of spatially resolved emissi…
The Dynamical State of the Frontier Fields Galaxy Cluster Abell 370
Sandor M. Molnar, Shutaro Ueda, Keiichi Umetsu
We study the dynamics of Abell 370 (A370), a highly massive Hubble Frontier Fields galaxy cluster, using self-consistent three-dimensional N-body/hydrodynamical simulations. Our si…
XRISM-Subaru views of Abell 754: an off-axis, near-line-of-sight merging cluster
Nobuhiro Okabe, Yuki Omiya, Kazuhiro Nakazawa +4
We report a weak-lensing (WL) mass measurement for the merging cluster Abell 754 and impose constraints on the merger trajectory. The trajectory analysis adopts a two-body model wi…
Development and Evaluation of a CNN-Based Charged-Particle Event Rejection Algorithm for Soft X-ray Detection in a pnCCD-Based Satellite System
Hsien-Chieh Shen, Ryuji Kondo, Makoto Arimoto +13
All-sky surveys in the soft X-ray band are essential for detecting transient objects such as high-redshift gamma-ray bursts (GRBs), which provide key insights into the early univer…
XRISM Observations of The Prototypical Cold Front in Abell 3667
Yuki Omiya, Yuto Ichinohe, Kazuhiro Nakazawa +13
We present high-resolution X-ray spectroscopy of the merging galaxy cluster Abell 3667 with \textit{XRISM}/Resolve. Two observations, targeting the cluster X-ray core and the proto…
Line-of-sight gas sloshing in the cool core of Abell 907
Shutaro Ueda, Yuto Ichinohe, Tetsu Kitayama +1
We present line-of-sight gas sloshing first found in a cool core in a galaxy cluster. The galaxy cluster Abell 907 is identified as a relaxed cluster owing to its global X-ray surf…
Search for Thermal X-ray Features from the Crab nebula with Hitomi Soft X-ray Spectrometer
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +192
The Crab nebula originated from a core-collapse supernova (SN) explosion observed in 1054 A.D. When viewed as a supernova remnant (SNR), it has an anomalously low observed ejecta m…
The relation between the cool-core radius and the host galaxy clusters: thermodynamic properties and cluster mass
FanLam Ng, Shutaro Ueda
We present a detailed study of cool-core systems in a sample of four galaxy clusters (RXCJ1504.1-0248, A3112, A4059, and A478) using archival X-ray data from the Chandra X-ray Obse…
Performance of a newly developed SDCCD for X-ray use
Hiroshi Tsunemi, Shutaro Ueda, Kazuo Shigeyama +3
A Scintillator Deposited CCD (SDCCD) is a wide-band X-ray detector consisting of a CCD and a scintillator directly attached to each other. We assembled the newly developed SDCCD th…
Gas Density Perturbations in Cool Cores of CLASH Galaxy Clusters
Shutaro Ueda, Yuto Ichinohe, Sandor M. Molnar +2
We present a systematic study of gas density perturbations in cool cores of high-mass galaxy clusters. We select 12 relaxed clusters from the Cluster Lensing And Supernova survey w…
Proton Radiation Damage Experiment on P-Channel CCD for an X-ray CCD camera onboard the Astro-H satellite
Koji Mori, Yusuke Nishioka, Satoshi Ohura +16
We report on a proton radiation damage experiment on P-channel CCD newly developed for an X-ray CCD camera onboard the Astro-H satellite. The device was exposed up to 10^9 protons…
Mapping the Perseus Galaxy Cluster with XRISM: Gas Kinematic Features and their Implications for Turbulence
Congyao Zhang, Irina Zhuravleva, Annie Heinrich +19
In this paper, we present extended gas kinematic maps of the Perseus cluster by combining five new XRISM/Resolve pointings observed in 2025 with four Performance Verification datas…
Three-dimensional thermodynamic structures of the intracluster medium across edges in the X-ray surface brightness of massive, bright, dynamically-active galaxy clusters
Shutaro Ueda, Yuto Ichinohe
We present a detailed study of three-dimensional (3D) thermodynamic structures of the intracluster medium (ICM) across edges in the X-ray surface brightness of four massive, bright…
Cool core disturbed: Observational evidence for coexistence of sub-sonic sloshing gas and stripped shock-heated gas around the core of RX J1347.5-1145
Shutaro Ueda, Tetsu Kitayama, Masamune Oguri +13
RXJ1347.5-1145 (z = 0.451) is one of the most luminous X-ray galaxy clusters, which hosts a prominent cool core and exhibits a signature of a major merger. We present the first dir…
The Quiescent Intracluster Medium in the Core of the Perseus Cluster
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +213
Clusters of galaxies are the most massive gravitationally-bound objects in the Universe and are still forming. They are thus important probes of cosmological parameters and a host…
XRISM-Subaru views of Abell 754: Energetic ICM Motions Revealed by XRISM/Resolve
Yuki Omiya, Nobuhiro Okabe, Kazuhiro Nakazawa +4
We present high-resolution X-ray spectroscopy of the merging cluster Abell~754 using \textit{XRISM}/Resolve. In GO1 phase, \textit{XRISM}/Resolve observed Abell 754 in two deep poi…
Atmospheric gas dynamics in the Perseus cluster observed with Hitomi
Hitomi Collaboration, Felix Aharonian, Hiroki Akamatsu +195
Extending the earlier measurements reported in Hitomi collaboration (2016, Nature, 535, 117), we examine the atmospheric gas motions within the central 100~kpc of the Perseus clust…
X-ray properties of high-richness CAMIRA clusters in the Hyper Suprime-Cam Subaru Strategic Program field
Naomi Ota, Ikuyuki Mitsuishi, Yasunori Babazaki +13
We present the first results of a pilot X-ray study of 37 rich galaxy clusters at in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) field. Diffuse X-ray emiss…