University of Surrey

Test tubes in the lab Research in the ATI Dance Research

Gravitational wave sources from inspiralling globular clusters in the Galactic Centre and similar environments

Arca-Sedda, Manuel and Gualandris, Alessia (2018) Gravitational wave sources from inspiralling globular clusters in the Galactic Centre and similar environments Monthly Notices of the Royal Astronomical Society, 477 (4). pp. 4423-4442.

[img]
Preview
Text
Gravitational wave sources from inspiralling globular clusters in the Galactic Centre and similar environments.pdf - Accepted version Manuscript
Available under License Creative Commons Attribution.

Download (3MB) | Preview

Abstract

We model the inspiral of globular clusters (GCs) towards a galactic nucleus harboring a supermassive black hole (SMBH), a leading scenario for the formation of nuclear star clusters.We consider the case of GCs containing either an intermediate-mass black hole (IMBH) or a population of stellar mass black holes (BHs), and study the formation of gravitational wave (GW) sources. We perform direct summation N-body simulations of the infall of GCs with different orbital eccentricities in the live background of a galaxy with either a shallow or steep density profile. We find that the GC acts as an efficient carrier for the IMBH, facilitating the formation of a bound pair. The hardening and evolution of the binary depends sensitively on the galaxy’s density profile. If the host galaxy has a shallow profile the hardening is too slow to allow for coalescence within a Hubble time, unless the initial cluster orbit is highly eccentric. If the galaxy hosts a nuclear star cluster, the hardening leads to coalescence by emission of GWs within 3−4 Gyr. In this case, we find a IMBH-SMBH merger rate of IIMBH−SMBH = 2.8×10−3 yr−1 Gpc−3. If the GC hosts a population of stellar BHs, these are deposited close enough to the SMBH to form extreme-mass-ratio-inspirals with a merger rate of IEMRI = 0.25 yr−1 Gpc−3. Finally, the SMBH tidal field can boost the coalescence of stellar black hole binaries delivered from the infalling GCs. The merger rate for this merging channel is IBHB = 0.4 − 4 yr−1 Gpc−3.

Item Type: Article
Divisions : Faculty of Engineering and Physical Sciences > Physics
Authors :
NameEmailORCID
Arca-Sedda, Manuel
Gualandris, Alessiaa.gualandris@surrey.ac.uk
Date : 16 April 2018
DOI : 10.1093/mnras/sty922
Copyright Disclaimer : This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2018 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Uncontrolled Keywords : Black hole physics. Galaxies: nuclei. Galaxies: star clusters: general. Galaxy: centre.
Depositing User : Clive Harris
Date Deposited : 13 Jul 2018 18:51
Last Modified : 13 Aug 2018 23:03
URI: http://epubs.surrey.ac.uk/id/eprint/848709

Actions (login required)

View Item View Item

Downloads

Downloads per month over past year


Information about this web site

© The University of Surrey, Guildford, Surrey, GU2 7XH, United Kingdom.
+44 (0)1483 300800