We investigate the evolution of intermediate-mass (IMBHs), stellar (BHs), and binary black holes (BHBs), deposited near a supermassive black hole (SMBH) by a population of massive star clusters. Stellar BHs rapidly segregate around the SMBH, driving the formation of extreme-mass ratio inspirals that coalesce at a rate Γ = 0.02-0.2 yr-1 Gpc-3 at redshift z = 0. A few IMBHs orbiting the SMBH favour the formation of massive pairs that coalescence within a Hubble time, being the merger rate for this channel Γ = 0.03 yr-1 Gpc-3. Recoiling kicks post-merger can eject the remnant from the galaxy centre, especially in dwarf galaxies. Our results suggest that this mechanism can lead to up to 105 ejected SMBH within 1 Gpc. An IMBH co-existing with a few single and binary BHs in the same cluster can affect significantly their evolution, either driving binary disruption, yielding to intermediate-mass ratio inspirals (merger rate Γ = 9.5 yr-1 Gpc-3), or boosting BHBs coalescence (Γ = 2-8 yr-1 Gpc-3). In a few simulations, the SMBH boosts BHBs coalescence, leading this process to a merger rate Γ = 1 yr-1 Gpc-3. We note that BHBs experiencing a merger in a galactic nucleus can be erroneously estimated {̃ } 30{{ per cent}} heavier than it really is because of the Doppler shift of the wave frequency as caused by the rapid motion around the SMBH. All our simulations are carried out using an N-body code tailored to treat close encounters and post-Newtonian dynamics, that includes also the galaxy field and dynamical friction in the particles equation of motion.

The MEGaN project II. Gravitational waves from intermediate-mass and binary black holes around a supermassive black hole / Arca-Sedda, M; Capuzzo-Dolcetta, R. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 483:1(2019), pp. 152-171. [10.1093/mnras/sty3096]

The MEGaN project II. Gravitational waves from intermediate-mass and binary black holes around a supermassive black hole

Arca-Sedda, M
Methodology
;
Capuzzo-Dolcetta, R
Supervision
2019

Abstract

We investigate the evolution of intermediate-mass (IMBHs), stellar (BHs), and binary black holes (BHBs), deposited near a supermassive black hole (SMBH) by a population of massive star clusters. Stellar BHs rapidly segregate around the SMBH, driving the formation of extreme-mass ratio inspirals that coalesce at a rate Γ = 0.02-0.2 yr-1 Gpc-3 at redshift z = 0. A few IMBHs orbiting the SMBH favour the formation of massive pairs that coalescence within a Hubble time, being the merger rate for this channel Γ = 0.03 yr-1 Gpc-3. Recoiling kicks post-merger can eject the remnant from the galaxy centre, especially in dwarf galaxies. Our results suggest that this mechanism can lead to up to 105 ejected SMBH within 1 Gpc. An IMBH co-existing with a few single and binary BHs in the same cluster can affect significantly their evolution, either driving binary disruption, yielding to intermediate-mass ratio inspirals (merger rate Γ = 9.5 yr-1 Gpc-3), or boosting BHBs coalescence (Γ = 2-8 yr-1 Gpc-3). In a few simulations, the SMBH boosts BHBs coalescence, leading this process to a merger rate Γ = 1 yr-1 Gpc-3. We note that BHBs experiencing a merger in a galactic nucleus can be erroneously estimated {̃ } 30{{ per cent}} heavier than it really is because of the Doppler shift of the wave frequency as caused by the rapid motion around the SMBH. All our simulations are carried out using an N-body code tailored to treat close encounters and post-Newtonian dynamics, that includes also the galaxy field and dynamical friction in the particles equation of motion.
2019
gravitational waves; galaxies: nuclei; galaxies: star clusters: general; Astrophysics - Astrophysics of Galaxies
01 Pubblicazione su rivista::01a Articolo in rivista
The MEGaN project II. Gravitational waves from intermediate-mass and binary black holes around a supermassive black hole / Arca-Sedda, M; Capuzzo-Dolcetta, R. - In: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY. - ISSN 0035-8711. - 483:1(2019), pp. 152-171. [10.1093/mnras/sty3096]
File allegati a questo prodotto
File Dimensione Formato  
Arca-Sedda_MEGaN_2019.pdf

solo gestori archivio

Tipologia: Documento in Post-print (versione successiva alla peer review e accettata per la pubblicazione)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 1.28 MB
Formato Adobe PDF
1.28 MB Adobe PDF   Contatta l'autore

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1249359
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 60
  • ???jsp.display-item.citation.isi??? 59
social impact