6 papers
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…
Chandra X-Ray Imaging and Spatially Resolved Spectroscopy of SN 1987A: Energy-Dependent Morphology of the Equatorial Ring
Yusuke Sakai, Shinya Yamada, Koji Mori +8
We present a systematic imaging and spatially resolved spectral study of SN 1987A using Chandra observations obtained between 1999 and 2025. By combining multiepoch ACIS and HETG d…
XRISM High-Resolution X-ray Spectroscopy of Cygnus X-1 -- Orbital and Short-Term Variability of Iron Absorption
Kaito Ninoyu, Shinya Yamada, Natalie Hell +19
We present the first high-resolution spectroscopy of the black hole high-mass X-ray binary Cygnus X-1 with XRISM, including orbital-phase-resolved analyses and tentative evidence o…
XRISM spectroscopy of a crowded Galactic center region -- I. Disentangling the sources in the field of view
Maxime Parra, Kai Matsunaga, Shifra Mandel +16
The Galactic center is a complex and crowded region hosting the supermassive black hole Sgr A*, numerous accreting compact objects, and diffuse X-ray emission. This paper presents…
Narrow iron- and nickel-K absorption lines from the eclipsing low-mass X-ray binary AX~J1745.62901
Kojiro Tanaka, Yoshitomo Maeda, Ryota Tomaru +23
We report the presence of a highly ionized absorber in the transient, eclipsing low-mass X-ray binary AX J1745.6-2901, observed from Feb. 26 to 29, 2024 with XRISM's Resolve and Xt…
Spectral and photometric variability of SS 433 observed with XRISM and simultaneous optical and near-infrared telescopes
Yusuke Sakai, Shinya Yamada, Yuta Okada +36
We present results from coordinated multiwavelength observations of the SS 433, obtained with XRISM, optical telescopes, and near-infrared camera during 2024 April and 2025 March.…