Mapping the Galactic Center with Gravitational Wave Measurements using Pulsar Timing
Abstract
We examine the nHz gravitational wave (GW) foreground of stars and black holes (BHs) orbiting SgrA* in the Galactic Center. A cusp of stars and BHs generates a continuous GW spectrum below 40 nHz; individual BHs within 1 mpc to SgrA* stick out in the spectrum at higher GW frequencies. The GWs and gravitational near-field effects can be resolved by timing pulsars within a few pc of this region. Observations with the Square Kilometer Array (SKA) may be especially sensitive to intermediate mass black holes (IMBHs) in this region, if present. A 100ns-10mus timing accuracy is sufficient to detect BHs of mass 1000 Msun with pulsars at distance 0.1-1 pc in a 3 yr observation baseline. Unlike electromagnetic imaging techniques, the prospects for resolving individual objects through GW measurements improve closer to SgrA*, even if the number density of objects increases inwards steeply. Scattering by the interstellar medium will pose the biggest challenge for such observations.
Cite
@article{arxiv.1110.6172,
title = {Mapping the Galactic Center with Gravitational Wave Measurements using Pulsar Timing},
author = {Bence Kocsis and Alak Ray and Simon Portegies Zwart},
journal= {arXiv preprint arXiv:1110.6172},
year = {2015}
}
Comments
12 pages, 3 figures, accepted for publication in ApJ