Is M82 X-1 really an intermediate-mass black hole? X-ray spectral and timing evidence

被引:39
作者
Fiorito, R [1 ]
Titarchuk, L
机构
[1] Univ Maryland, College Pk, MD 20742 USA
[2] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA
[3] George Mason Univ, CEOSR, Fairfax, VA 22030 USA
[4] USN, Res Lab, Washington, DC 20375 USA
关键词
accretion; accretion disks; black hole physics; radiation mechanisms : nonthermal;
D O I
10.1086/425736
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Ultraluminous X-ray sources (ULXs) with apparent luminosities up to hundreds of times the Eddington luminosity for a neutron star have been discovered in external galaxies. The existence of intermediate-mass black holes has been proposed to explain these sources. We present evidence for an intermediate-mass black hole in the ULX M82 X-1 based on the spectral features and timing (quasi-periodic oscillation [QPO]) properties of the X-radiation from this source. We revisited XMM-Newton and Rossi X-Ray Timing Explorer (RXTE) data for M82 X-1 obtained in 2001 and 1997 for XMM and RXTE, respectively. We show for these observations that the source is either in transition or in a high/soft state with photon spectral indices 2.1 and 2.7, respectively. We confirm the early determination of the QPO frequency v approximate to 55 mHz in this source by Strohmayer & Mushotzky and identify this as the low- frequency QPO for the source. We apply a new method to determine the black hole mass of M82 X-1. The method uses the index-QPO low-frequency correlation that has been recently established in Galactic black hole candidates GRS 1915 + 105, XTE J1550-564, 4U 1630-47, and others. Using scaling arguments and the correlation derived from the consideration of Galactic black holes, we conclude that M82 X-1 is an intermediate black hole with a mass of the order of 1000 M-circle dot.
引用
收藏
页码:L113 / L116
页数:4
相关论文
共 17 条
[1]   The nature of accreting black holes in nearby galaxy nuclei [J].
Colbert, EJM ;
Mushotzky, RF .
ASTROPHYSICAL JOURNAL, 1999, 519 (01) :89-107
[2]  
FIORITO R, 2003, AAS HEAD M 11 07, V35
[3]   Ultraluminous X-ray sources in external galaxies [J].
King, AR ;
Davies, MB ;
Ward, MJ ;
Fabbiano, G ;
Elvis, M .
ASTROPHYSICAL JOURNAL, 2001, 552 (02) :L109-L112
[4]   X-ray spectroscopic evidence for intermediate-mass black holes: Cool accretion disks in two ultraluminous X-ray sources [J].
Miller, JM ;
Fabbiano, G ;
Miller, MC ;
Fabian, AC .
ASTROPHYSICAL JOURNAL, 2003, 585 (01) :L37-L40
[5]   Evidence for harmonic relationships in the high-frequency quasi-periodic oscillations of XTE J1550-564 and GRO J1655-40 [J].
Remillard, RA ;
Muno, MP ;
McClintock, JE ;
Orosz, JA .
ASTROPHYSICAL JOURNAL, 2002, 580 (02) :1030-1042
[6]   Characterizing the quasi-periodic oscillation behavior of the X-ray nova XTE J1550-564 [J].
Remillard, RA ;
Sobczak, GJ ;
Muno, MP ;
McClintock, JE .
ASTROPHYSICAL JOURNAL, 2002, 564 (02) :962-973
[7]   RXTE view of the starburst galaxies M82 and NGC 253 [J].
Rephaeli, Y ;
Gruber, D .
ASTRONOMY & ASTROPHYSICS, 2002, 389 (03) :752-760
[8]   A method for black hole mass determination in accretion-powered X-ray sources [J].
Shrader, CR ;
Titarchuk, L .
ASTROPHYSICAL JOURNAL, 2003, 598 (01) :168-177
[9]   Correlations between low-frequency quasi-periodic oscillations and spectral parameters in XTE J1550-564 and GRO J1655-40 [J].
Sobczak, GJ ;
McClintock, JE ;
Remillard, RA ;
Cui, W ;
Levine, AM ;
Morgan, EH ;
Orosz, JA ;
Bailyn, CD .
ASTROPHYSICAL JOURNAL, 2000, 531 (01) :537-545
[10]   X-ray nova XTE J1550-564:: RXTE spectral observations [J].
Sobczak, GJ ;
McClintock, JE ;
Remillard, RA ;
Levine, AM ;
Morgan, EH ;
Bailyn, CD ;
Orosz, JA .
ASTROPHYSICAL JOURNAL, 1999, 517 (02) :L121-L125