Search Publications
A large sample of shear-selected clusters from the Hyper Suprime-Cam Subaru Strategic Program S16A Wide field mass maps
Miyatake, Hironao; Oguri, Masamune; Umetsu, Keiichi +13 more
We present the result of searching for clusters of galaxies based on weak gravitational lensing analysis of the ∼160 deg2 area surveyed by Hyper Suprime-Cam (HSC) as a Subaru Strategic Program. HSC is a new prime focus optical imager with a 1.5°-diameter field of view on the 8.2 m Subaru telescope. The superb median seeing on the HSC i-…
Hitomi observation of radio galaxy NGC 1275: The first X-ray microcalorimeter spectroscopy of Fe-Kα line emission from an active galactic nucleus
Done, Chris; Safi-Harb, Samar; Hamaguchi, Kenji +191 more
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 broad line region, a molecular torus, or interstellar/intracluster media. In 2016 February-March, we performed the first X-ray microcalorimeter spectroscopy with the Soft X…
Temperature structure in the Perseus cluster core observed with Hitomi
Done, Chris; Safi-Harb, Samar; Hamaguchi, Kenji +192 more
The present paper explains the temperature structure of X-ray emitting plasma in the core of the Perseus cluster based on 1.8-20.0 keV data obtained with the Soft X-ray Spectrometer (SXS) on board the Hitomi Observatory. A series of four observations was carried out, with a total effective exposure time of 338 ks that covered a central region of ∼…
Suzaku X-ray observations of the mixed-morphology supernova remnant CTB 1
Takahashi, Tadayuki; Uchida, Hiroyuki; Uchiyama, Yasunobu +6 more
We present an X-ray study of the mixed-morphology supernova remnant CTB 1 (G116.9+0.2) observed with Suzaku. The 0.6-2.0 keV spectra in the northeastern breakout region of CTB 1 are well represented by a collisional ionization-equilibrium plasma model with an electron temperature of ∼0.3 keV, whereas those in the southwestern inner-shell region ca…
Magnetic field analysis of the bow and terminal shock of the SS 433 jet
Nakanishi, Hiroyuki; Akamatsu, Hiroki; Akahori, Takuya +4 more
We report a polarization analysis of the eastern region of W 50, observed with the Australia Telescope Compact Array (ATCA) at 1.4-3.0 GHz. In order to study the physical structures in the region where the SS 433 jet and W 50 interact, we obtain an intrinsic magnetic field vector map of that region. We find that the orientation of the intrinsic ma…
Multiwavelength study of X-ray luminous clusters in the Hyper Suprime-Cam Subaru Strategic Program S16A field
Hoshino, Akio; Fukazawa, Yasushi; Nakazawa, Kazuhiro +34 more
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 catalog in the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey field with S16A data. As a pilot study for a series of papers, we measure hydrostatic equilib…
Can the relativistic light-bending model explain X-ray spectral variations of Seyfert galaxies?
Tsujimoto, Masahiro; Ebisawa, Ken; Mizumoto, Misaki +3 more
Many Seyfert galaxies are known to exhibit Fe-K broad emission line features in their X-ray energy spectra. The observed lines have three distinct features: (1) the line profiles are skewed and show significant low-energy tails, (2) the Fe-K band has low variability, which produces a broad and deep dip in the root-mean-square (rms) spectra, and (3…
Suzaku observations of low surface brightness cluster Abell 1631
Matsumoto, Hironori; Mitsuishi, Ikuyuki; Ota, Naomi +5 more
We present analysis results for a nearby galaxy cluster Abell 1631 at z = 0.046 using the X-ray observatory Suzaku. This cluster is categorized as a low X-ray surface brightness cluster. To study the dynamical state of the cluster, we conduct four-pointed Suzaku observations and investigate physical properties of the Mpc-scale hot gas associated w…
High entropy and evidence for a merger in the low surface brightness cluster Abell 2399
Mitsuishi, Ikuyuki; Ota, Naomi; Babazaki, Yasunori +4 more
We present results of the X-ray analyses of the nearby cluster of galaxies Abell 2399 (z = 0.058) using the XMM-Newton and Suzaku satellites. This cluster is classified as a low surface brightness (LSB) cluster. It has a bimodal structure in X-rays, and the X-ray-emission peaks are significantly offset from the peaks in gas temperature. By de-proj…
X-ray-bright optically faint active galactic nuclei in the Subaru Hyper Suprime-Cam wide survey
Greene, Jenny E.; Ueda, Yoshihiro; Terashima, Yuichi +8 more
We construct a sample of X-ray-bright optically faint active galactic nuclei by combining Subaru Hyper Suprime-Cam, XMM-Newton, and infrared source catalogs. Fifty-three X-ray sources satisfying i-band magnitude fainter than 23.5 mag and X-ray counts with the EPIC-PN detector larger than 70 are selected from 9.1 deg2, and their spectral…