Eccentricity distributions of eccentric binary black holes in galactic nuclei. (arXiv:1812.04012v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Takatsy_J/0/1/0/all/0/1">János Takátsy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Becsy_B/0/1/0/all/0/1">Bence Bécsy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Raffai_P/0/1/0/all/0/1">Peter Raffai</a>
Galactic nuclei are expected to be one of the main sites for formations of
eccentric binary black holes (EBBHs), with an estimated detection rate of
$mathcal{O}(1-100$ yr$^{-1}$) with Advanced LIGO (aLIGO) detectors operating
at design sensitivity. Two of the main formation channels of these binaries are
gravitational capture and the secular Kozai-Lidov mechanism, with expectedly
commensurable formation rates. We used Monte Carlo simulations to construct the
eccentricity distributions of EBBHs formed through these channels in galactic
nuclei, at the time their gravitational-wave signals enter the aLIGO band at
$10$ Hz. We have found that the proportion of binary black holes entering the
aLIGO band with eccentricities larger than $0.1$ is $sim 10$ percent for the
secular Kozai-Lidov mechanism, and $sim 90$ percent for gravitational capture.
We show that if future EBBH detection rates with aLIGO will be dominated by
EBBHs formed in galactic nuclei, then the proportions of EBBHs formed through
the two main channels can be constrained to a $Delta mathcal{F}= 0.2$ wide
one-sigma confidence interval with a few tens of observations, even if
parameter estimation errors are taken into account at realistic levels.
Galactic nuclei are expected to be one of the main sites for formations of
eccentric binary black holes (EBBHs), with an estimated detection rate of
$mathcal{O}(1-100$ yr$^{-1}$) with Advanced LIGO (aLIGO) detectors operating
at design sensitivity. Two of the main formation channels of these binaries are
gravitational capture and the secular Kozai-Lidov mechanism, with expectedly
commensurable formation rates. We used Monte Carlo simulations to construct the
eccentricity distributions of EBBHs formed through these channels in galactic
nuclei, at the time their gravitational-wave signals enter the aLIGO band at
$10$ Hz. We have found that the proportion of binary black holes entering the
aLIGO band with eccentricities larger than $0.1$ is $sim 10$ percent for the
secular Kozai-Lidov mechanism, and $sim 90$ percent for gravitational capture.
We show that if future EBBH detection rates with aLIGO will be dominated by
EBBHs formed in galactic nuclei, then the proportions of EBBHs formed through
the two main channels can be constrained to a $Delta mathcal{F}= 0.2$ wide
one-sigma confidence interval with a few tens of observations, even if
parameter estimation errors are taken into account at realistic levels.
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