Daniel J. D'Orazio

Accretion into the central cavity of a circumbinary disc

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

THE MIGRATION OF GAP-OPENING PLANETS IS NOT LOCKED TO VISCOUS DISK EVOLUTION

q=M_2/M_1

Relativistic boost as the cause of periodicity in a massive black-hole binary candidate

in the range

A reduced orbital period for the supermassive black hole binary candidate in the quasar PG 1302-102?

0.01 \leq q \leq 1

A transition in circumbinary accretion discs at a binary mass ratio of 1:25

. 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

Periodic self-lensing from accreting massive black hole binaries

\sim 5

Big black hole, little neutron star: Magnetic dipole fields in the Rindler spacetime

, compared to a disk with a single BH with the same mass; (ii) the largest suppression occurs for

An analytic solution for weak-field Schwarzschild geodesics

q\approx 0.05

Black Hole Mergers from Globular Clusters Observable by LISA and LIGO: Results from post-Newtonian Binary-Single Scatterings

; binaries whose mass ratios are either lower or higher both suppress accretion less significantly; (iii) for

A Single Progenitor Model for GW150914 and GW170104

q \gtrsim 0.05