Stochastic Background of Gravitational Waves Generated by Black Hole MACHO Binaries in the Galaxy

The interest in gravitational waves (GW) has increased since the recent detections of such signals announced by the LIGO Scientific Collaboration and the Virgo Collaboration. On the other hand, also interesting is the study of the stochastic backgrounds of GW (SBGW), which could in principle be generated by a variety of sources and astrophysical processes; particularly, in the present paper we are concerned with the SBGW from MACHO binaries in the Galaxy. In our scheme, we take into account only MACHOs which are black holes (BHMACHOs) and are located up to 50 kpc from the center of the Galaxy. Our spectra, which are calculated in the scenarios with Ωh2=0.1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega h^{2}=0.1$$\end{document} and Ωh2=1.0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega h^{2}=1.0$$\end{document}, are parameterized by the fraction of the Galaxy’s dark halo mass which is in the form of BHMACHOs and are compared with some results found in the literature. Besides, we investigate in what situations the backgrounds are above the sensitivity curves of the Laser Interferometer Space Antenna (LISA), Einstein Telescope (ET), Advanced Virgo (AdV) and Advanced Laser Interferometer Gravitational-Wave Observatory Plus (LIGO A+).