Evolution of the temporal and the spectral properties in 2010 and 2011 outbursts of H 1743-322

TL;DR

This study analyzes the spectral and temporal evolution of two X-ray outbursts of H 1743-322 in 2010 and 2011, using RXTE data to understand accretion flow dynamics and state transitions.

Contribution

It applies the Propagating Oscillatory Shock model to fit QPO evolution and characterizes accretion flow parameters during different spectral states in both outbursts.

Findings

QPO frequencies modeled successfully with POS model

Outbursts divided into four spectral states based on spectral and timing properties

Different types of mass accretion flows explain the outburst profiles

Abstract

The Galactic black hole candidate H~1743-322 exhibited two X-ray outbursts in rapid succession: one in August 2010 and the other in April 2011. We analyze archival data of this object from the PCA instrument on board RXTE (2-25 keV energy band) to study the evolution of its temporal and spectral characteristics during both the outbursts, and hence to understand the behavioral change of the accretion flow dynamics associated with the evolution of the various X-ray features. We study the evolution of QPO frequencies during the rising and the declining phases of both the outbursts. We successfully fit the variation of QPO frequency using the Propagating Oscillatory Shock (POS) model in each of the outbursts and obtain the accretion flow parameters such as the instantaneous shock locations, the shock velocity and the shock strength. Based on the degree of importance of the thermal (disk black body) and the non-thermal (power-law) components of the spectral fit and properties of the QPO (if present), the entire profiles of the 2010 and 2011 outbursts are subdivided into four different spectral states: hard, hard-intermediate, soft-intermediate and soft. We attempt to explain the nature of the outburst profile (i.e., hardness-intensity diagram) with two different types of mass accretion flow.