Belczynski 2007 短暴的黑洞双星演化和引力波辐射

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文章信息:
Black Hole Spin Evolution: Implications for Short-hard Gamma Ray Bursts and Gravitational Wave Detection

Authors: Krzysztof Belczynski, Ronald E. Taam, Emmanouela Rantsiou, Marc van der Sluys

(Submitted on 6 Mar 2007)

Abstract: The evolution of the spin and tilt of black holes in compact black hole - neutron star and black hole - black hole binary systems is investigated via the population synthesis method. Based on recent results on accretion at super Eddington rates in slim disk models, estimates of natal kicks, and the results regarding fallback in supernova models, we obtain the black hole spin and misalignment. It is found that the spin parameter, a_spin, is less than 0.5 for initially non rotating black holes and the tilt, i_tilt, is less than 40 deg for 50% of the systems in black hole - neutron star binaries. Upon comparison with the results of black hole - neutron star merger calculations we estimate that only a small fraction (~0.02) of these systems can potentially produce a short-hard gamma ray burst. Only for high initial black hole spin parameters (a_spin>0.6) can this fraction be significant (~0.35). For the majority of black holes in black hole - neutron star systems the spin magnitude is increased to a_spin>0.1 and the degree of spin misalignment (i_tilt ~ 40 deg) is sufficiently high that the predicted gravitational radiation signal significantly differs from that for non rotating black holes. However, due to the (i) insensitivity of signal detection techniques to the black hole spin and the (ii) predicted overall low contribution of black hole binaries to the signal we find that the detection of gravitational waves are not greatly inhibited by current searches with non spinning templates. It is pointed out that the detection of a black hole - black hole binary inspiral system with LIGO or VIRGO may provide a direct measurement of the initial spin of a black hole.

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19 pages, 3 tables, 10 figures: submitted to ApJ

Subjects:

Astrophysics (astro-ph)

Cite as:

arXiv:astro-ph/0703131v1