Modeling the Spectrum of IGR J17177-3656

TL;DR

This study models multi-band observations of the transient X-ray source IGR J17177-3656, demonstrating it follows a steep radio/X-ray correlation and is best explained by luminous hot accretion flow rather than ADAF.

Contribution

The paper provides the first detailed modeling of IGR J17177-3656's spectrum, showing it as an outlier with a steep radio/X-ray correlation explained by LHAF.

Findings

IGR J17177-3656 follows a steep radio/X-ray correlation.

Luminous hot accretion flow successfully models the spectrum.

Supports LHAF as an explanation for steep radio/X-ray correlation.

Abstract

The correlation between radio and X-ray luminosity in the hard state of black hole X-ray binaries is important for unveiling the relation between the accretion flow and the jets. In this paper, we have modeled the quasi-simultaneous multi-band observations of a recently discovered transient X-ray source, IGR J17177-3656. It is found that the source is probably an outlier following the steep radio/X-ray correlation rather than an outlier in the transition region as suggested by Paizis et al. (2011). It is also found that the multi-band spectrum can be successfully modeled by the luminous hot accretion flow (LHAF) but less likely by the advection dominated accretion flow (ADAF). Our results support the point that LHAF can explain the steep radio/X-ray correlation.