A nonthermal bomb explains the near-infrared superflare of Sgr A*

TL;DR

This paper proposes a nonthermal bomb model involving particle acceleration events like magnetic reconnection to explain the unprecedented near-infrared superflare observed in Sgr A* in 2019.

Contribution

It introduces the nonthermal bomb concept as a new explanation for superflare phenomena in supermassive black holes, linking particle acceleration to observed luminosity increases.

Findings

The nonthermal bomb model can account for the 2019 Sgr A* superflare.

Multiwavelength observations can test the model's validity.

Potential mechanisms include magnetic reconnection and relativistic turbulence.

Abstract

The Galactic center supermassive black hole, Sgr A*, has experienced a strong, unprecedented flare in May 2019 when its near-infrared luminosity reached much brighter levels than ever measured. We argue that an explosive event of particle acceleration to nonthermal energies in the innermost parts of the accretion flow---a nonthermal bomb---explains the near-IR light curve. We discuss potential mechanisms that could explain this event such as magnetic reconnection and relativistic turbulence acceleration. Multiwavelength monitoring of such superflares in radio, infrared and X-rays should allow a concrete test of the nonthermal bomb model and put better constraints on the mechanism that triggered the bomb.