An unusual timing and spectral state of a black hole microquasar XTE J1550–564

• Published in: Research in astronomy and astrophysics Vol. 9; no. 2; pp. 179 - 190
• Main Authors: Jin, Ying-Kang, Zhang, Shuang-Nan, Li, Ti-Pei
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.02.2009; Department of Engineering Physics and Center for Astrophysics, Tsinghua University, Beijing 100084, China%Department of Physics and Center for Astrophysics, Tsinghua University, Beijing 100084, China; Department of Physics and Center for Astrophysics, Tsinghua University, Beijing 100084, China; Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China; Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China%Department of Engineering Physics and Center for Astrophysics, Tsinghua University, Beijing 100084, China
• Subjects: data analysis-X-rays; individual (XTE J1550-564); methods; binaries-X-rays
• ISSN: 1674-4527
• DOI: 10.1088/1674-4527/9/2/007

P1; An unusual timing and spectral state of a black hole microquasar XTE J1550-564 observed with RXTE is analyzed. Millisecond variabilities are found, which are significantly shorter than the minimum possible time scale in the light curves of black hole binaries, as suggested by Sunyaev & Revnivtsev (2000). The X-ray spectral fitting result indicates that there is an unusual soft component in the spectrum, which may be responsible for the millisecond variabilities. The millisecond variabilities as well as the unusual soft spectral component should be produced from some small, but independent active regions in the accretion disk.