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キーワード:
Astrophysics, Cosmology and Extragalactic Astrophysics, astro-ph.CO, Astrophysics, Galaxy Astrophysics, astro-ph.GA,General Relativity and Quantum Cosmology, gr-qc
要旨:
Even though the existence of intermediate-mass black holes has not yet been
corroborated observationally, these objects are of high interest for
astrophysics. Our understanding of formation and evolution of supermassive
black holes (SMBHs), as well as galaxy evolution modeling and cosmography would
dramatically change if an IMBH was observed. The prospect of detection and,
possibly, observation and characterization of an IMBH has good chances in
lower-frequency gravitational-wave (GW) astrophysics with ground-based
detectors such as LIGO, Virgo and the future Einstein Telescope (ET). We
present an analysis of the signal of a system of a binary of IMBHs based on a
waveform model obtained with numerical relativity simulations coupled with
post-Newtonian calculations at the highest available order so as to extend the
waveform to lower frequencies. We find that initial LIGO and Virgo are in the
position of detecting IMBHs with a signal-to-noise ratio (SNR) of $\sim 10$ for
systems with total mass between 100 and $500 M_{\odot}$ situated at a distance
of 100 Mpc. Nevertheless, the event rate is too low and the possibility that
these signals are mistaken with a glitch is, unfortunately, non-negligible.
When going to second- and third-generation detectors, such as Advanced LIGO or
the proposed ET, the event rate becomes much more promising (tens per year for
the first and thousands per year for the latter) and the SNR at 100 Mpc is as
high as 100 -- 1000 and 1000 -- $10^{5}$ respectively. The prospects for IMBH
detection and characterization with ground-based GW observatories would not
only provide us with a robust test of general relativity, but would also
corroborate the existence of these systems. Such detections would be a probe to
the stellar environments of IMBHs and their formation.
