2014/08/15 by Kazunari Eda, Yousuke Itoh, Sachiko Kuroyanagi +1 · 1 citation
Physics and Astronomy · #gr-qc #astro-ph.CO #astro-ph.HE
paper · pdf · doi:10.1103/physrevd.91.044045
published as Phys. Rev. D 91, 044045 (2015) · 19 pages, 8 figures
arxiv created 2014/08/15 · arxiv updated 2015/03/04
Recent studies show that an intermediate mass black hole (IMBH) may develop a dark matter (DM) mini-halo according to some BH formation scenarios. We consider a binary system composed of an IMBH surrounded by a DM mini-spike and a stellar mass object orbiting around the IMBH. The binary evolves due to gravitational pull and dynamical friction from the DM mini-spike and back-reaction from its gravitational wave (GW) radiation which can be detected by future space-borne GW experiments such as eLISA/NGO. We consider a single power-law model for the DM mini-spike which is assumed to consist of non-annihilating DM particles and demonstrate that an eLISA/NGO detection of GW from such a binary enables us to measure the DM mini-spike parameters very accurately. For instance, in our reference case originally advocated by Zhao and Silk (2005) and Bertone et al. (2005), we could determine the power-law index α of the DM mini-spike radial profile with a 1 σ relative error of ± 5× 10-6 for a GW signal with signal-to-noise-ratio 10 and assuming a 5 year observation with eLISA. We also investigate how accurately the DM parameters can be determined for various DM parameters and the masses of the IMBH-stellar mass object binary surrounded by a DM mini-spike. We find that we can determine the power-law index α at 10 % level even for a slightly flatter radial distribution of α∼ 1.7.