APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Chris Belczynski (WARSAW UNIVERSITY)
Title: Comparison of LIGO/Virgo upper limits with predicted compact binary merger rates
Date (JST): Wed, Jan 27, 2016, 15:40 - 16:40
Place: Seminar Room A
Related File: 1583.pdf
Abstract: We compare evolutionary predictions of double compact object merger rate
densities with initial and forthcoming LIGO/Virgo upper limits. We find

(i) Due to the cosmological reach of advanced detectors, current
conversion methods of population synthesis predictions into merger
rate densities are insufficient.

(ii) Our optimistic models are a factor of 18 below the initial
LIGO/Virgo upper limits for BH-BH systems, indicating that a modest
increase in observational sensitivity (by a factor of 2.5) may bring
the first detections or first gravitational wave constraints on binary

(iii) Stellar-origin massive BH-BH mergers should dominate event rates
in advanced LIGO/Virgo and can be detected out to redshift z=2 with
templates including inspiral, merger, and ringdown. Normal stars (<150
Msun) can produce such mergers with total redshifted mass up to 400

(iv) High black hole natal kicks can severely limit the formation of
massive BH-BH systems (both in isolated binary and in dynamical dense
cluster evolution), and thus would eliminate detection of these
systems even at full advanced LIGO/Virgo sensitivity. We find that low
and high black hole natal kicks are allowed by current observational
electromagnetic constraints.

(v) The majority of our models yield detections of all types of
mergers with advanced detectors. Numerous massive BH-BH merger
detections will indicate small (if any) natal kicks for massive
BHs. These systems would also shed light on the merger origin,
possibly distinguishing mergers arising from field binary evolution
(aligned spins) and dense clusters (misaligned spins).