THE CLOSE STELLAR COMPANIONS TO INTERMEDIATE-MASS BLACK HOLES

被引:48
作者
MacLeod, Morgan [1 ]
Trenti, Michele [2 ]
Ramirez-Ruiz, Enrico [1 ]
机构
[1] Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA
[2] Univ Melbourne, Sch Phys, Melbourne, Vic 3010, Australia
基金
美国国家科学基金会;
关键词
black hole physics; galaxies: dwarf; globular clusters: general; gravitation; gravitational waves; methods: numerical; ESO; 243-49; HLX-1; X-RAY SOURCE; YOUNG STAR-CLUSTERS; GRAVITATIONAL-WAVE EMISSION; MINOR MERGER SCENARIO; SGR-A-ASTERISK; GLOBULAR-CLUSTERS; TIDAL DISRUPTION; DYNAMICAL EVOLUTION; WHITE-DWARFS;
D O I
10.3847/0004-637X/819/1/70
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
When embedded in dense cluster cores, intermediate-mass black holes (IMBHs) acquire close stellar or stellarremnant companions. These companions are not only gravitationally bound, but also tend to hierarchically isolate from other cluster stars through series of multibody encounters. In this paper we study the demographics of IMBH companions in compact star clusters through direct N-body simulations. We study clusters initially composed of 10(5) or 2 x 10(5) stars with IMBHs of 75 and 150 solar masses, and we follow their evolution for 6-10 Gyr. A tight, innermost binary pair of IMBH and stellar object rapidly forms. The IMBH has a companion with an orbital semimajor axis at least three times tighter than the second-most-bound object over 90% of the time. These companionships have typical periods on the order of years and are subject to cycles of exchange and destruction. The most frequently observed, long-lived pairings persist for similar to 10(7) years. The demographics of IMBH companions in clusters are diverse: they include both main-sequence, giant stars and stellar remnants. Companion objects may reveal the presence of an IMBH in a cluster in one of several ways. The most-bound companion stars routinely suffer grazing tidal interactions with the IMBH, offering a dynamical mechanism to produce repeated flaring episodes like those seen in the IMBH candidate HLX-1. The stellar winds of companion stars provide a minimum quiescent accretion rate for IMBHs, with implications for radio searches for IMBH accretion in globular clusters. Finally, gravitational wave inspirals of compact objects occur with promising frequency.
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页数:19
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共 166 条
[1]   From NBODY1 to NBODY6: The growth of an industry [J].
Aarseth, SJ .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC, 1999, 111 (765) :1333-1346
[2]   Intermediate and extreme mass-ratio inspirals - astrophysics, science applications and detection using LISA [J].
Amaro-Seoane, Pau ;
Gair, Jonathan R. ;
Freitag, Marc ;
Miller, M. Coleman ;
Mandel, Ilya ;
Cutler, Curt J. ;
Babak, Stanislav .
CLASSICAL AND QUANTUM GRAVITY, 2007, 24 (17) :R113-R169
[3]  
[Anonymous], 2003, Gravitational N-Body Simulations
[4]   STAR DISTRIBUTION AROUND A MASSIVE BLACK-HOLE IN A GLOBULAR CLUSTER [J].
BAHCALL, JN ;
WOLF, RA .
ASTROPHYSICAL JOURNAL, 1976, 209 (01) :214-232
[5]   A ∼ 50,000 M⊙ SOLAR MASS BLACK HOLE IN THE NUCLEUS OF RGG 118 [J].
Baldassare, Vivienne F. ;
Reines, Amy E. ;
Gallo, Elena ;
Greene, Jenny E. .
ASTROPHYSICAL JOURNAL LETTERS, 2015, 809 (01)
[6]   Tidal capture of stars by intermediate-mass black holes [J].
Baumgardt, H. ;
Hopman, C. ;
Portegies Zwart, S. ;
Makino, J. .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2006, 372 (01) :467-478
[7]   Massive black holes in star clusters. II. Realistic cluster models [J].
Baumgardt, H ;
Makino, J ;
Ebisuzaki, T .
ASTROPHYSICAL JOURNAL, 2004, 613 (02) :1143-1156
[8]   Which globular clusters contain intermediate-mass black holes? [J].
Baumgardt, H ;
Makino, J ;
Hut, P .
ASTROPHYSICAL JOURNAL, 2005, 620 (01) :238-243
[9]   Massive black holes in star clusters. I. Equal-mass clusters [J].
Baumgardt, H ;
Makino, J ;
Ebisuzaki, T .
ASTROPHYSICAL JOURNAL, 2004, 613 (02) :1133-1142
[10]   THE DYNAMICAL STATE OF THE GLOBULAR CLUSTER M10 (NGC 6254) [J].
Beccari, G. ;
Pasquato, M. ;
De Marchi, G. ;
Dalessandro, E. ;
Trenti, M. ;
Gill, M. .
ASTROPHYSICAL JOURNAL, 2010, 713 (01) :194-204