Tidal Disruptions of Main-sequence Stars. V. The Varieties of Disruptions

Julian Krolik*, Tsvi Piran, Taeho Ryu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Scopus citations

Abstract

Tidal disruption events (TDEs) are generally imagined as the complete disruption of a star when it passes close to a supermassive black hole (SMBH). Relativistic apsidal precession is thought to quickly "circularize"the bound debris, forming a compact accretion disk, which then emits a flare of standardized light curve and spectrum. We show here that this picture holds in only a minority of cases. TDEs are more diverse and can be grouped into several categories distinguished by stellar pericenter distance r p; we estimate the relative frequency of these categories. Rapid circularization is rare both because it requires () and because most events with lead to direct capture. For larger pericenter distances, (for M BH = 106 M o), main-sequence stars with M ∗ ≲ 3 are completely disrupted, but the bound debris orbits are highly eccentric and possess semimajor axes ∼100× the scale of the expected compact disk. Partial disruptions with fractional mass loss 10% occur with a rate similar to that of total disruptions; for fractional mass loss 50%, the rate is ≈1/3 as large. Partial disruptions-which must precede total disruptions when the stars' angular momenta evolve in the "empty loss-cone"regime-change the orbital energy by factors O(1). Partial disruption remnants are in general far from thermal equilibrium. Depending on its orbital energy and conditions within the stellar cluster surrounding the SMBH, a remnant may return after ∼O(100)-O(1000) yr and be fully disrupted, or it may rejoin the stellar cluster.

Original languageEnglish
Article number68
JournalAstrophysical Journal
Volume904
Issue number1
DOIs
StatePublished - 23 Nov 2020

Bibliographical note

Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved..

Keywords

  • Black hole physics (159)
  • Galactic center (565)
  • General relativity (641)
  • Gravitation (661)
  • Stellar dynamics (1596)
  • Supermassive black holes (1663)

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