Accretion into the central cavity of a circumbinary disc

By D. D’Orazio, Zoltán Haiman, A. MacFadyen. 2012

201 citations recorded by the source corpus.

A near-equal mass binary black hole can clear a central cavity in a circumbinary accretion disk; however, previous works have revealed accretion streams entering this cavity. Here we use 2D hydrodynamical simulations to study the accretion streams and their periodic behavior. In particular, we perform a suite of simulations, covering different binary mass ratios $q=M_2/M_1$ in the range $0.01 \leq q \leq 1$. In each case, we follow the system for several thousand binary orbits, until it relaxes to a stable accretion pattern. We find the following results: (i) while the binary is efficient in maintaining a low-density cavity, the time-averaged mass accretion rate into the cavity, through narrow coherent accretion streams, is suppressed by at most a factor of $\sim 5$, compared to a disk with a single BH with the same mass; (ii) the largest suppression occurs for $q\approx 0.05$; binaries whose mass ratios are either lower or higher both suppress accretion less significantly; (iii) for $q \gtrsim 0.05$, the accretion rate is strongly modulated by the binary, and depending on the precise value of $q$, the power spectrum of the accretion rate shows either one, two, or three distinct periods; and (v) for $q \lesssim 0.05$, the accretion rate becomes steady, with no time-variations. Most binaries produced in galactic mergers are expected to have $q\gtrsim 0.05$. If the luminosity of these binaries tracks their accretion rate, then a periodogram of their light-curve could help in their identification, and to constrain their mass ratio and disk properties.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/467e63536bc04cdeb9edad4cde0a2411e4390b03

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. Zoltán Haiman
2. M. Volonteri
3. A. Sesana
4. L. Hernquist
5. M. Colpi
6. E. Lusso
7. M. Dotti
8. S. Bianchi

Citations in the corpus

• The quest for dual and binary supermassive black holes: A multi-messenger view (2019, background): “05, the disk is steady and the BH accretion rate displays no strong variability (D’Orazio et al., 2013; Farris et al., 2014; D’Orazio et al., 2016).”