Patterns of X-ray and $\gamma$-ray Flares: from Blazar to Maganetar and Sun

TL;DR

This study uses Gaussian process analysis to compare the variability patterns of solar X-ray flares, a fast radio burst-associated X-ray burst, and blazar gamma-ray flares, revealing potential commonalities in their dynamic behaviors and underlying mechanisms.

Contribution

It introduces a Gaussian process-based method to analyze extreme flaring events across different astrophysical sources and identifies a possible critical damping condition linking solar flares, X-ray bursts, and gamma-ray flares.

Findings

Solar X-ray flares follow a stochastic SHO model with specific PSD break timescales.

FRB-associated X-ray burst has a Q value near 0.3, similar to some solar flares.

Blazar gamma-ray flares show higher Q values, indicating different dynamic behavior.

Abstract

Using Gaussian process methods, we analyzed the light curves of three extreme solar X-ray flares observed by the RHESSI satellite. Their variability characteristics were then compared with those of HXMT-HE X-ray burst (XRB; in SGR 1935+2154) associated with fast radio burst (FRB) 200428 and blazar $\gamma$-ray giant flares, to investigate the origins of these extreme flaring events. The variability patterns of the solar X-ray flares follow the stochastically driven damped simple harmonic oscillator (SHO) model. The derived timescales $t_{\rm B\underline{} steep}$ and $t_{\rm B\underline{~} flat}$ (corresponding to PSD breaks) are in the range of 4-7 s and 16-53 s, respectively. The FRB-associated HXMT-HE burst has a $Q$ value near 0.3, matching those of the solar flares occurred on 23 July 2002 (flare 1) and 3 November 2003 (flare 2). By contrast, blazar $\gamma$-ray giant flares show $Q >$ 0.3, similar to the solar flare occurred on 25 February 2014 (flare 3). We proposed that the critically damped state of the system may be the condition triggering the association between the XRB in SGR 1935+2154 and the FRB. In this scenario, the critical damping $Q$ value of the system is around 0.3, not the theoretical 0.5. The similarity in $Q$ values might imply that the FRB-associated HXMT-HE XRB and solar X-ray flares 1 $\&$ 2 share comparable dynamic behavior, while blazar $\gamma$-ray flares and solar X-ray flare 3 exhibit another distinct but similar dynamic behavior. Like solar X-ray flares, these extreme flares may all be related to the magnetic reconnection process.