2022/01/31 by Elisa Bortolas
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Initial mass function #Milky Way #Physics #Star formation #Stellar mass #astro-ph.CO #astro-ph.GA #astro-ph.HE #astro-ph.IM #astro-ph.SR #msc:85A05
paper · pdf · doi:10.1093/mnras/stac262
12 pages, 7 figures, 1 table. Accepted for publication in MNRAS. Corrected typo in Equation (1)
openalex publication_date 2022/01/31 · arxiv created 2022/02/14 · arxiv updated 2022/02/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
ABSTRACT A tidal disruption event (TDE) occurs when a star is destroyed by the strong tidal shear of a massive black hole (MBH). The accumulation of TDE observations over the last years has revealed that post-starburst galaxies are significantly overrepresented in the sample of TDE hosts. Here we address the post-starburst preference by investigating the decline of TDE rates in a Milky-Way like nuclear stellar cluster featuring either a monochromatic (1 M\odot ) or a complete, evolved stellar mass function. In the former case, the decline of TDE rates with time is very mild, and generally up to a factor of a few in 10 Gyr. Conversely, if a complete mass function is considered, a strong TDE burst over the first 0.1–1 Gyr is followed by a considerable rate drop, by at least an order of magnitude over 10 Gyr. The decline starts after a mass segregation time-scale, and it is more pronounced assuming a more top-heavy initial mass function and/or an initially denser nucleus. Our results thus suggest that the post-starburst preference can be accounted for in realistic systems featuring a complete stellar mass function, even in moderately dense galactic nuclei. Overall, our findings support the idea that starbursting galactic nuclei are characterized by a top-heavy initial mass function; we speculate that accounting for this can reconcile the discrepancy between observed and theoretically predicted TDE rates even in quiescent galaxies.