IGR J17091-3624: a GRS 1915-105 like source as seen by INTEGRAL and Swift

TL;DR

This paper analyzes the outbursts of the black hole candidate IGR J17091-3624, comparing its unique variability patterns to GRS 1915+105, based on extensive observations from INTEGRAL and Swift, and discusses possible explanations and the system's evolution.

Contribution

It provides the first detailed comparison of IGR J17091-3624's variability with GRS 1915+105 using multi-year INTEGRAL and Swift data, exploring hypotheses for its unique behavior.

Findings

2011 outburst showed GRS 1915+105-like variability at different flux levels

Multiple hypotheses discussed to explain the unique variability behavior

Overall analysis suggests complex evolutionary state of the binary system

Abstract

We present here the main characteristics of the BHC IGR J17091-3624 outbursts occurred several times since 1994. Since 2003, the source has been extensively observed by INTEGRAL and Swift. In particular, we report results on the last 2011 outburst that showed a rare variability behaviour observed before only in the galactic BH GRS 1915+105 but at a different level of flux. Several hypotheses have been proposed in order to explain this particular behaviour. They are all discussed here, in the light of their apparent contradiction. Finally, based on all available informations, we attempt to give an overall view of this enigmatic source and we speculate on the evolutionary state of the binary system.