The optical, UV-plateau, and X-ray tidal disruption event luminosity functions reproduced from first principles

Journal article

We reproduce the luminosity functions of the early-time peak optical, the late-time ultraviolet (UV)-plateau, and the peak X-ray luminosities of tidal disruption events, using an entirely first-principles theoretical approach. We do this by first fitting three free parameters of the tidal disruption event black hole mass distribution using the observed distribution of late-time UV-plateau luminosities, using a time-dependent relativistic accretion model. Using this black hole mass distribution we are then, with no further free parameters of the theory, able to reproduce exactly the peak X-ray luminosity distribution of the tidal disruption event population. This proves that the X-ray luminosity of tidal disruption events are sourced from the same accretion flows which produce the late-time UV plateau. Using an empirical scaling relationship between peak optical luminosities and black hole masses, itself calibrated using the same relativistic accretion theory, we are able to reproduce the observed peak optical luminosity function, again with no additional free parameters. Implications of these results include that there is no tidal disruption event ‘missing energy problem’, that the optical- and X-ray-selected tidal disruption event populations are drawn from the same black hole mass distribution, that the early-time optical luminosity in tidal disruption events is somewhat simple, at least on the population level, and that future Legacy Survey of Space and Time (LSST) observations will be able to constrain the black hole mass function at low masses.

Authors: Mummery, A; van Velzen, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 541
• Issue: 1
• Pages: 429-445
• Publication date: 2025-06-30
• Acceptance date: 2025-05-28
• DOI: 10.1093/mnras/staf938
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: black hole physics; accretion, accretion discs; transients: tidal disruption events