[1108.5161] Hubble without the Hubble: cosmology using advanced gravitational-wave detectors alone

Authors: Stephen R. Taylor, Jonathan R. Gair, Ilya Mandel

Date: 25 Aug 2011

Abstract: We propose a novel approach to measuring the Hubble constant using gravitational-wave signals from compact binaries by exploiting the narrowness of the distribution of masses of the underlying neutron-star population. The Advanced LIGO gravitational wave detector is due to come online in 2015 with a factor of ~10 sensitivity increase over its predecessor. The volume-averaged range at which an inspiraling double-neutron-star binary can be detected should increase from ~15 Mpc to ~200 Mpc, providing a thousand-fold gain in the volume sensitivity of the detector. Incorporating AdLIGO into a global network (through AdVirgo or LIGO-Australia) will boost the directional sensitivity and permit source distance determination. In this paper, we explore what we can learn about the background cosmology and the mass distribution of neutron stars from the set of neutron star (NS) mergers detected by such a network. We use a Bayesian formalism to analyse catalogues of NS-NS inspiral detections. We find that it is possible to constrain the Hubble constant, H_0, and the parameters of the NS mass function using gravitational-wave data alone, without relying on electromagnetic counterparts. Under reasonable assumptions, we will be able to determine H_0 to +/- 10% using ~100 observations, provided the Gaussian half-width of the underlying double NS mass distribution is less than 0.04 M_{\odot}. The expected precision depends linearly on the intrinsic width of the NS mass function, but has only a weak dependence on H_0 near the default parameter values. Finally, we consider what happens if, for some fraction of our data catalogue, we have an electromagnetically measured redshift. The detection, and cataloguing, of these compact object mergers will allow precision astronomy, and provide a determination of H_0 which is independent of the local distance scale.

abs pdf

Sep 09, 2011

1108.5161 (/preprints)
2011-09-09, 06:59 [edit]

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