Was an Outburst of Aquila X-1 a Magnetic Flare?

TL;DR

This paper suggests that the 2009 outburst of Aquila X-1 may have been caused by a large magnetic flare from its accretion disk corona, based on similarities with solar flares in light curves and luminosity ratios.

Contribution

It proposes a novel interpretation linking the X-ray outburst of Aquila X-1 to magnetic flares, supported by comparative analysis with solar flare properties.

Findings

Similarity in radio and X-ray light curves to solar flares

Luminosity ratios comparable to weak solar flares

Radio spectrum near 8 GHz matches solar flare characteristics

Abstract

I point to an interesting similarity in the radio and the soft X-ray light curves between the November 2009 outburst of the X-ray binary Aquila X-1 and some solar flares. The ratio of the soft X-ray and radio luminosities of Aquila X-1 in that outburst is also similar to some weak solar flares, and so is the radio spectrum near 8 GHz. Based on these, as well as on some other recent studies that point to some similar properties of accretion disk coronae and stellar flares, such as ratio of radio to X-ray luminosities (Laor & Behar 2008), I speculate that the soft X-ray outburst of Aquila X-1 was related to a huge magnetic flare from its disk corona.