X-RAY SPECTRAL STATE IS NOT CORRELATED WITH LUMINOSITY IN HOLMBERG II X-1

被引:32
|
作者
Grise, F. [1 ]
Kaaret, P. [1 ]
Feng, H. [2 ,3 ]
Kajava, J. J. E. [4 ]
Farrell, S. A. [5 ]
机构
[1] Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA
[2] Tsinghua Univ, Dept Engn Phys, Beijing 100084, Peoples R China
[3] Tsinghua Univ, Ctr Astrophys, Beijing 100084, Peoples R China
[4] Univ Oulu, Astron Div, Dept Phys, Oulu 90014, Finland
[5] Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England
关键词
accretion; accretion disks; black hole physics; X-rays: binaries; X-rays: individual (Holmberg II X-1); BLACK-HOLE BINARIES; GRS 1915+105; ESO; 243-49; GALAXY; VARIABILITY; TRANSITIONS; EVOLUTION; EMISSION; MASSES; PERIOD;
D O I
10.1088/2041-8205/724/2/L148
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
The ultraluminous X-ray source (ULX) Holmberg II X-1 has been observed over four months in 2009/2010 by the Swift observatory. The source luminosity varied by a factor of up to 14, reaching a maximum 0.3-10 keV luminosity of similar to 3.0 x 10(40) erg s(-1). The spectral properties do not vary much over these four months, with only a slight monotonic increase of the hardness ratio with the count rate. This means that the erratic flaring activity of the source is not associated with spectral changes, as seen in other ULXs. Conversely, comparison with data obtained by Swift in 2006 shows a completely different picture: while at a luminosity also seen in the 2009/2010 data, the source appears with a hard spectrum. Thus, it appears that, as in Galactic black hole binaries, spectral states in this ULX are not determined only by the X-ray luminosity.
引用
收藏
页码:L148 / L152
页数:5
相关论文
共 50 条
  • [21] X-RAY SPECTRAL CUTOFF AND THE LACK OF HARD X-RAY EMISSION FROM TWO ULTRALUMINOUS X-RAY SOURCES M81 X-6 AND HOLMBERG IX X-1
    Dewangan, G. C.
    Jithesh, V.
    Misra, R.
    Ravikumar, C. D.
    ASTROPHYSICAL JOURNAL LETTERS, 2013, 771 (02)
  • [22] Spectral state transitions of the Ultraluminous X-ray Source IC 342 X-1
    Marlowe, H.
    Kaaret, P.
    Lang, C.
    Feng, H.
    Grise, F.
    Miller, N.
    Cseh, D.
    Corbel, S.
    Mushotzky, R. F.
    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2014, 444 (01) : 642 - 650
  • [23] Spectral variability of the X-ray pulsar Hercules X-1
    A. A. Lutovinov
    S. A. Grebenev
    M. N. Pavlinsky
    R. A. Sunyaev
    Astronomy Letters, 2000, 26 : 691 - 698
  • [24] Spectral variability of the X-ray pulsar Hercules X-1
    Lutovinov, AA
    Grebenev, SA
    Pavlinsky, MN
    Sunyaev, RA
    ASTRONOMY LETTERS-A JOURNAL OF ASTRONOMY AND SPACE ASTROPHYSICS, 2000, 26 (11): : 691 - 698
  • [25] First Detection of Mid-infrared Variability from an Ultraluminous X-Ray Source Holmberg II X-1
    Lau, R. M.
    Heida, M.
    Kasliwal, M. M.
    Walton, D. J.
    ASTROPHYSICAL JOURNAL LETTERS, 2017, 838 (02)
  • [26] Correlated optical and X-ray emission from SCO X-1
    McNamara, B
    Harrison, T
    Zavala, R
    Mirales, O
    Olivaras, D
    Galvan, J
    Galvan, E
    FIFTH COMPTON SYMPOSIUM, 2000, 510 : 227 - 230
  • [27] Detection of a Radio Bubble around the Ultraluminous X-Ray Source Holmberg IX X-1
    Berghea, Ciprian T.
    Johnson, Megan C.
    Secrest, Nathan J.
    Dudik, Rachel P.
    Hennessy, Gregory S.
    El-Khatib, Aisha
    ASTROPHYSICAL JOURNAL, 2020, 896 (02):
  • [28] X-ray and γ-ray spectra of Cyg X-1 in the soft state
    Gierlinski, M
    Zdziarski, AA
    Dotani, T
    Ebisawa, K
    Jahoda, K
    Johnson, WN
    PROCEEDINGS OF THE FOURTH COMPTON SYMPOSIUM, PTS 1 AND 2: PT 1: THE COMPTON OBSERVATORY IN REVIEW; PT 2: PAPERS AND PRESENTATIONS, 1997, (410): : 844 - 848
  • [29] X-ray spectral evolution of Her X-1 in a low state and the following short high state
    Inam, SC
    Baykal, A
    MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2005, 361 (04) : 1393 - 1398
  • [30] Hard X-ray spectral and temporal observations of SCO X-1
    1600, Publ by Univ of Adelaide, Adelaide, Aust