The fine line between total and partial tidal disruption events

• Published in: Astronomy and astrophysics (Berlin) Vol. 600; p. A124
• Main Authors: Mainetti, Deborah, Lupi, Alessandro, Campana, Sergio, Colpi, Monica, Coughlin, Eric R., Guillochon, James, Ramirez-Ruiz, Enrico
• Format: Journal Article
• Language: English
• Published: EDP Sciences 01.04.2017
• Subjects: accretion; accretion disks; Astronomy; Astrophysics; black hole physics; Black holes (astronomy); Disruption; Flares; Galaxies; galaxies: nuclei; hydrodynamics; Mathematical analysis; methods: numerical; Physics; Simulation; Stars; accretion; hydrodynamics; black hole physics; methods: numerical; galaxies: nuclei; accretion disks
• ISSN: 0004-6361; 1432-0746; 1432-0756
• DOI: 10.1051/0004-6361/201630092

Flares from tidal disruption events are unique tracers of quiescent black holes at the centre of galaxies. The appearance of these flares is very sensitive to whether the star is totally or partially disrupted, and in this paper we seek to identify the critical distance of the star from the black hole (rd) that enables us to distinguish between these two outcomes. We perform here mesh-free finite mass, traditional, and modern smoothed particle hydrodynamical simulations of star-black hole close encounters, with the aim of checking if the value of rd depends on the simulation technique. We find that the critical distance (or the so-called critical disruption parameter βd) depends only weakly on the adopted simulation method, being βd = 0.92 ± 0.02 for a γ = 5/3 polytrope and βd = 2.01 ± 0.01 for a γ = 4/3 polytrope.