2020/06/17 by F. J. Sanchez-Salcedo · 1 citation
Physics and Astronomy · #astro-ph.GA #astro-ph.EP
paper · pdf · doi:10.3847/1538-4357/ab9b2d
17 pages, 24 figures, accepted for publication in ApJ
arxiv created 2020/06/17 · arxiv updated 2020/07/22
Using two-dimensional simulations, we compute the torque and rate of work (power) on a low-mass gravitational body, with softening length R\rm soft, embedded in a gaseous disk when its orbit is eccentric and retrograde with respect to the disk. We explore orbital eccentricities e between 0 and 0.6. We find that the power has its maximum at e≃ 0.25(h/0.05)2/3, where h is the aspect ratio of the disk. We show that the power and the torque converge to the values predicted in the local (non-resonant) approximation of the dynamical friction (DF) when R\rm soft tends to zero. For retrograde inspirals with mass ratios \lesssim 5× 10-4 embedded in disks with h≥ 0.025, our simulations suggest that (i) the rate of inspiral barely depends on the orbital eccentricity and (ii) the local approximation provides the value of this inspiral rate within a factor of 1.5. The implications of the results for the orbital evolution of extreme mass-ratio inspirals are discussed.