IGR J12580+0134: A Candidate for Repeating Partial Tidal Disruption Events Supported by Multi-Wavelength Observations

TL;DR

This study investigates whether the late-time radio rebrightening of IGR J12580+0134 can be explained as a repeating partial tidal disruption event, using multi-wavelength observations and modeling to support its candidacy.

Contribution

The paper presents multi-epoch radio and X-ray observations and models the second radio rebrightening episode as a non-relativistic outflow, proposing IGR J12580+0134 as a candidate for a repeating pTDE.

Findings

Two distinct radio rebrightening episodes separated by ~1513 days.

Modeling favors a non-relativistic outflow with velocity ~0.03c.

No significant X-ray brightening during the 2016 radio flare.

Abstract

Repeating partial tidal disruption events (pTDEs) provide a direct probe of stellar orbits and episodic mass loss around supermassive black holes, but robust identification requires multi-band and multi-epoch evidence. We investigate whether the late-time radio rebrightening of the nuclear transient IGR J12580+0134 in NGC 4845 can be explained as a repeating pTDE, using multi-epoch Karl G. Jansky VLA observations together with X-ray constraints from Swift/XRT and NICER. The radio light curves show two distinct episodes, with the L-band peaks separated by $\approx1513$ days. Modeling the second episode with a synchrotron afterglow framework using Markov Chain Monte Carlo fitting favors a non-relativistic outflow $v\simeq0.03c$, with an isotropic-equivalent kinetic energy of order $10^{50}$ erg propagating in an approximately constant-density circumnuclear medium. No significant contemporaneous brightening is detected by Swift/XRT during the 2016 radio flare, while faint NICER flares in 2023 suggest intermittent low-level accretion. The recurrence timescale and radio energetics therefore make IGR J12580+0134 a possible candidate for a repeating pTDE system, motivating continued sensitive radio and X-ray monitoring to test future reactivations.