Paper: astro-ph/0603441
Date: Fri, 17 Mar 2006 09:53:09 GMT (221kb)

Title: Detection Rate Estimates of Gravity-waves Emitted During Parabolic
Encounters of Stellar Black Holes in Globular Clusters

Authors: Bence Kocsis, Merse E. Gaspar, Szabolcs Marka

Comments: 18 pages, 8 figures, submitted to ApJ
\\
The rapid advance of gravitational-wave (GW) detector facilities makes it
very important to estimate the event rates of possible detection candidates. We
consider an additional possibility of GW bursts produced during parabolic
encounters (PEs) of stellar mass compact objects. We estimate the rate of
successful detections for specific detectors: the initial Laser Interferometric
Gravitational-Wave Observatory (InLIGO), the French-Italian gravitational-wave
antenna VIRGO, the near-future Advanced-LIGO (AdLIGO), the space-based Laser
Interferometric Space Antenna (LISA), and the Next Generation LISA (NGLISA).
Simple GC models are constructed to account for the compact object mass
function, mass segregation, number density distribution, and velocity
distribution. We calculate encounters both classically and account for general
relativistic corrections by extrapolating the results for infinite mass ratios.
We also include the cosmological redshift of waveforms and event rates. We find
that typical PEs with masses m_1=m_2=40 Msun are detectable with matched
filtering over a signal to noise ratio of 5 within a distance d_L~200Mpc for
InLIGO and VIRGO, z=1 for AdLIGO, 0.4Mpc for LISA, and 1Gpc for NGLISA. We
estimate single datastream total detection rates of 5.5 x 10^{-5} for InLIGO,
7.2 x 10^{-5} for VIRGO, 0.063 for AdLIGO, 2.9 x 10^{-6} for LISA, and 1.0 for
NGLISA per year, for reasonably conservative assumptions. These estimates are
subject to uncertainties in the GC parameters, most importantly the total
number and mass-distribution of black holes (BHs) in the cluster core. In
reasonably optimistic cases, we get >~1 detections for AdLIGO per year. The
regular detection of GWs during PEs would provide a unique observational probe
for constraining the stellar BH mass function of dense clusters. (abridged)

\\ ( http://arXiv.org/abs/astro-ph/0603441 , 221kb)