Saved in:
Bibliographic Details
Main Authors: Li, Xinyu, Sun, Houyi, Zou, Yuan-Chuan, Yang, Huan
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2501.13702
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911304879439872
author Li, Xinyu
Sun, Houyi
Zou, Yuan-Chuan
Yang, Huan
author_facet Li, Xinyu
Sun, Houyi
Zou, Yuan-Chuan
Yang, Huan
contents This work explores a scenario for micro-tidal disruption events (TDEs) triggered by close encounters between high-speed white dwarfs (WDs) and stellar-mass black holes (sBHs) in galactic centers. In this model, a WD orbiting the central massive black hole (MBH) is scattered by an sBH during the sBH's early extreme mass-ratio inspiral phase. We conservatively estimate these events occur a few times per year within $z\leq 3$. Significant disruption of the WD occurs when the impact parameter is comparable to the WD's radius. We derive a mathematical criterion and confirm numerically by hydrodynamical simulations. With the increase of the impact parameter and the collision speed, the WD material captured by the sBH decreases while the material remain self-gravitating increases. A part of the WD material becomes unbound from the sBH-WD system, and its mass ranges from nearly zero to $\ge 50\%$, reaching the peak value when the impact parameter is comparable to the WD's radius. We expect the subsequent capture of WD material by the sBH to produce a prompt X-ray burst (a micro-TDE), and the accretion of unbound debris onto the MBH can power a fainter, delayed optical flare. The properties of certain transient X-ray bursts observed by Einstein Probe are consistent with this micro-TDE picture.
format Preprint
id arxiv_https___arxiv_org_abs_2501_13702
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Micro-Tidal Disruption Events at Galactic Centers
Li, Xinyu
Sun, Houyi
Zou, Yuan-Chuan
Yang, Huan
High Energy Astrophysical Phenomena
General Relativity and Quantum Cosmology
This work explores a scenario for micro-tidal disruption events (TDEs) triggered by close encounters between high-speed white dwarfs (WDs) and stellar-mass black holes (sBHs) in galactic centers. In this model, a WD orbiting the central massive black hole (MBH) is scattered by an sBH during the sBH's early extreme mass-ratio inspiral phase. We conservatively estimate these events occur a few times per year within $z\leq 3$. Significant disruption of the WD occurs when the impact parameter is comparable to the WD's radius. We derive a mathematical criterion and confirm numerically by hydrodynamical simulations. With the increase of the impact parameter and the collision speed, the WD material captured by the sBH decreases while the material remain self-gravitating increases. A part of the WD material becomes unbound from the sBH-WD system, and its mass ranges from nearly zero to $\ge 50\%$, reaching the peak value when the impact parameter is comparable to the WD's radius. We expect the subsequent capture of WD material by the sBH to produce a prompt X-ray burst (a micro-TDE), and the accretion of unbound debris onto the MBH can power a fainter, delayed optical flare. The properties of certain transient X-ray bursts observed by Einstein Probe are consistent with this micro-TDE picture.
title Micro-Tidal Disruption Events at Galactic Centers
topic High Energy Astrophysical Phenomena
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2501.13702