Discovery and state transitions of the new Galactic black hole candidate MAXI J1535−571

PASJ: Publications of the Astronomical Society of Japan

Yamaoka, Kazutaka¹  Makishima, Kazuo²  Kawase, Tomofumi³  Kawai, Nobuyuki³  Morita, Kotaro⁴  Mihara, Tatehiro⁵  Shidatsu, Megumi⁶  Ueda, Yoshihiro⁶  Nakahira, Satoshi⁶  Negoro, Hitoshi⁶ 

[1] Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto, Kyoto 606-8502, Japan;Department of Physics, Ehime University, 2-5 Bunkyocho, Matsuyama, Ehime 790-8577, Japan;Department of Physics, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308, Japan;Department of Physics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551, Japan;Institute for Space-Earth Environmental Research (ISEE), Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan;MAXI team, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan

关键词: X-rays: binaries;    X-rays: bursts;    accretion, accretion disks;    black hole physics;   

DOI  :  10.1093/pasj/psy093

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

We report on the detection and subsequent X-ray monitoring of the new Galactic black hole candidate MAXI J1535−571 with the Gas Slit Camera onboard Monitor of All-sky X-ray Image (MAXI/GSC). After the discovery on 2017 September 2, made independently with MAXI and the Swift/BAT, the source brightened gradually, and in a few weeks reached the peak intensity of ∼5 Crab, or ∼1.6 × 10−7 erg cm−2 s−1 in terms of the 2–20 keV flux. On the initial outburst rise, the 2–20 keV MAXI/GSC spectrum was described by a power-law model with a photon index of ≲ 2, while after a hard-to-soft transition, which occurred on September 18, the spectrum required a disk blackbody component in addition. At around the flux peak, the 2–8 keV and 15–50 keV light curves showed quasi-periodic and anti-correlated fluctuations with amplitudes of 10%–20%, on a time scale of ∼1 d. Based on these X-ray properties obtained with the MAXI/GSC, with additional information from the Swift/BAT, we discuss the evolution of the spectral state of this source, and give constraints on its system parameters.

【 授权许可】

CC BY