124 citations · 419 across the 36 of their papers we have counts for
37 papers
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…
Three-Dimensional Expansion of Iron Ejecta in Cassiopeia A with Chandra and XRISM
Aya Bamba, Tomoki Kadoya, Kouichi Hagino +4
Measurement of the expansion structure of ejecta in supernova remnants (SNRs) provides important information about their explosion mechanism. We combine Chandra proper-motion measu…
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…
A Weak Fe K Emission Line in the Broad-Line Radio Galaxy 3C 111 Observed with XRISM: An Ionized Wind Absorption Feature?
Kouichi Hagino, Motoki Kino, Lukasz Stawarz +3
We present the results of an observation of the broad-line radio galaxy 3C 111 with the X-Ray Imaging and Spectroscopy Mission (XRISM). The unprecedentedly high spectral resolution…
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…
Resolving the Multiple Component Outflows in PG 1211+143: II. The Soft X-ray View of the Ultra Fast Outflow
James Reeves, Valentina Braito, Misaki Mizumoto +16
The nearby quasar, PG 1211+143, has one of the prototype examples of an ultra fast outflow (UFO), as seen in several past XMM-Newton and Chandra observations. In December 2024, PG…
A XRISM/Resolve view of the dynamics in the hot gaseous atmosphere of M87
XRISM Collaboration, M. Audard, H. Awaki +138
The XRISM/Resolve microcalorimeter directly measured the gas velocities in the core of the Virgo Cluster, the closest example of AGN feedback in a cluster. This proximity allows us…
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…
Resolving the Multiple Component Outflows in PG 1211+143: I. The Fe-K Absorption Structure and UFO Forest
Misaki Mizumoto, James N. Reeves, Valentina Braito +15
We present the initial high-resolution X-ray spectroscopic observations of the Fe-K absorption structure in the luminous nearby quasar PG 1211+143, utilizing the X-ray Imaging and…
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…
Discovery of Powerful Multi-Velocity Ultra-Fast Outflows in the Starburst Merger Galaxy IRAS 051892524 with XRISM
Hirofumi Noda, Satoshi Yamada, Shoji Ogawa +17
We observed the X-ray-bright ultra-luminous infrared galaxy, IRAS 051892524, with XRISM during its performance verification phase. The unprecedented energy resolution of the onb…
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 (…
Non-local orbital-free density functional theory incorporating nuclear shell effects
Xinhui Wu, Gianluca Colò, Kouichi Hagino +1
Incorporating nuclear shell effects within the framework of orbital-free density functional theory (DFT) has remained a longstanding challenge in nuclear physics. While the Hohenbe…
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…
The electron temperature distribution and the high ionization just behind the shock in the Cygnus Loop
Masahiro Ichihashi, Aya Bamba, Dai Tateishi +6
The physical processes behind astrophysical collisionless shocks, such as thermal relaxation and ionization after shock passage, remain poorly understood. To investigate these proc…
Development of Solar Flare X-ray Polarimeter with Micro-Pixel CMOS Sensors
Kouichi Hagino, Tatsuaki Kato, Toshiya Iwata +10
We are developing an X-ray polarimeter using micro-pixel CMOS sensors for solar flare X-ray polarimetry. The system consists of a 2.5-m pixel CMOS image sensor with a 12.8$\time…
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…
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…
Probing surface vibration of spherical nuclei in relativistic heavy-ion collisions
Kouichi Hagino, Masakiyo Kitazawa
There has been increasing interest in recent years in using relativistic heavy-ion collisions to probe nuclear structure, such as static nuclear deformation. Here we discuss the ro…
Delving into the depths of NGC 3783 with XRISM. I. Kinematic and ionization structure of the highly ionized outflows
Missagh Mehdipour, Jelle S. Kaastra, Megan E. Eckart +17
We present our study of the XRISM observation of the Seyfert-1 galaxy NGC 3783. XRISM's Resolve microcalorimeter has enabled, for the first time, a detailed characterization of the…
XRISM analysis of the complex Fe K line in Centaurus A
David Bogensberger, Yuya Nakatani, Tahir Yaqoob +14
We analyze the high-resolution XRISM/Resolve spectrum of the Fe K emission line of the nearest active galactic nucleus, in Centaurus A. The line features two narrow and resolved…
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…
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…
Constraining gas motion and non-thermal pressure beyond the core of the Abell 2029 galaxy cluster with XRISM
XRISM Collaboration, Marc Audard, Hisamitsu Awaki +137
We report a detailed spectroscopic study of the gas dynamics and hydrostatic mass bias of the galaxy cluster Abell 2029, utilizing high-resolution observations from XRISM Resolve.…