Late-time Evolution and Instabilities of Tidal Disruption Disks

Observations of tidal disruption events on timescales of years after the main flare show evidence of continued activity in the form of optical/UV emission, quasiperiodic eruptions, and delayed radio flares. Motivated by this, we explore the time evolution of these disks, using semi-analytic models t...

Full description

Saved in:
Bibliographic Details
Main Authors: Anthony L. Piro, Brenna Mockler
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
Subjects:
Online Access:https://doi.org/10.3847/1538-4357/adc729
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850135319923392512
author Anthony L. Piro
Brenna Mockler
author_facet Anthony L. Piro
Brenna Mockler
author_sort Anthony L. Piro
collection DOAJ
description Observations of tidal disruption events on timescales of years after the main flare show evidence of continued activity in the form of optical/UV emission, quasiperiodic eruptions, and delayed radio flares. Motivated by this, we explore the time evolution of these disks, using semi-analytic models to follow the changing disk properties and feeding rate to the central black hole. We find that thermal instabilities typically begin ∼100 days after the TDE, causing the disk to cycle between high and low accretion states for up to ∼10 yr. The high state is super-Eddington, which may be associated with outflows that eject ∼10 ^−3 –10 ^−1 M _⊙ over ∼1–2 days, with a range of velocities ∼0.03–0.3 c . Collisions between these mass ejections may cause radio flares. In the low state, the accretion rate slowly grows over months to years, as continued fallback accretion builds the disk’s mass. In this phase, the disk has a luminosity of ∼10 ^41 –10 ^42 erg s ^−1 in the optical/UV, as seen in some late-time observations. Although the accretion cycles we find occur for a typical α -disk, in nature, the disk could be stabilized by other effects, such as the disk’s magnetic field or heating from fallback accretion, the latter of which we explore. Thus, higher-cadence optical/UV observations along with joint radio monitoring will be key for following the disk state and testing these models.
format Article
id doaj-art-72c5c40035ee4401b9b38ea32ee535b3
institution OA Journals
issn 1538-4357
language English
publishDate 2025-01-01
publisher IOP Publishing
record_format Article
series The Astrophysical Journal
spelling doaj-art-72c5c40035ee4401b9b38ea32ee535b32025-08-20T02:31:27ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-0198517710.3847/1538-4357/adc729Late-time Evolution and Instabilities of Tidal Disruption DisksAnthony L. Piro0https://orcid.org/0000-0001-6806-0673Brenna Mockler1https://orcid.org/0000-0001-6350-8168The Observatories of the Carnegie Institution for Science , Pasadena, CA 91101, USA , piro@carnegiescience.eduThe Observatories of the Carnegie Institution for Science , Pasadena, CA 91101, USA , piro@carnegiescience.eduObservations of tidal disruption events on timescales of years after the main flare show evidence of continued activity in the form of optical/UV emission, quasiperiodic eruptions, and delayed radio flares. Motivated by this, we explore the time evolution of these disks, using semi-analytic models to follow the changing disk properties and feeding rate to the central black hole. We find that thermal instabilities typically begin ∼100 days after the TDE, causing the disk to cycle between high and low accretion states for up to ∼10 yr. The high state is super-Eddington, which may be associated with outflows that eject ∼10 ^−3 –10 ^−1 M _⊙ over ∼1–2 days, with a range of velocities ∼0.03–0.3 c . Collisions between these mass ejections may cause radio flares. In the low state, the accretion rate slowly grows over months to years, as continued fallback accretion builds the disk’s mass. In this phase, the disk has a luminosity of ∼10 ^41 –10 ^42 erg s ^−1 in the optical/UV, as seen in some late-time observations. Although the accretion cycles we find occur for a typical α -disk, in nature, the disk could be stabilized by other effects, such as the disk’s magnetic field or heating from fallback accretion, the latter of which we explore. Thus, higher-cadence optical/UV observations along with joint radio monitoring will be key for following the disk state and testing these models.https://doi.org/10.3847/1538-4357/adc729AccretionTransient sourcesTidal disruptionSupermassive black holes
spellingShingle Anthony L. Piro
Brenna Mockler
Late-time Evolution and Instabilities of Tidal Disruption Disks
The Astrophysical Journal
Accretion
Transient sources
Tidal disruption
Supermassive black holes
title Late-time Evolution and Instabilities of Tidal Disruption Disks
title_full Late-time Evolution and Instabilities of Tidal Disruption Disks
title_fullStr Late-time Evolution and Instabilities of Tidal Disruption Disks
title_full_unstemmed Late-time Evolution and Instabilities of Tidal Disruption Disks
title_short Late-time Evolution and Instabilities of Tidal Disruption Disks
title_sort late time evolution and instabilities of tidal disruption disks
topic Accretion
Transient sources
Tidal disruption
Supermassive black holes
url https://doi.org/10.3847/1538-4357/adc729
work_keys_str_mv AT anthonylpiro latetimeevolutionandinstabilitiesoftidaldisruptiondisks
AT brennamockler latetimeevolutionandinstabilitiesoftidaldisruptiondisks