Preferential accretion and circumbinary disc precession in eccentric binary systems

ABSTRACT We present a suite of high-resolution hydrodynamic simulations binaries immersed in circumbinary accretion discs (CBDs). For the first time, we investigate preferential rate as function both eccentricity eb and mass ratio qb densely sampled parameter space, finding that when compared with circular binaries, (i) ratios grow more efficiently on moderately eccentric orbits (0.0 ? 0.4), (ii) high eccentricities (eb ? 0.6) suppress growth. suggest this non-monotonic behaviour may produce an observable shift distributions stellar massive black hole binaries. further find response CBD can be divided into three regimes, depending ratio: CBDs around always precess freely, whereas either undergo forced precession or (iii) remain locked at angle respect to binary periapsis. Forced is associated strong modulation individual rates time-scale, potentially signature accreting short orbital periods. provide locking angles for our simulation suite.