The 2009 outburst from the new X-ray transient and black-hole candidate XTE J1652$-$453

TL;DR

This paper analyzes RXTE and Swift observations of the 2009 outburst of the black-hole candidate XTE J1652-453, revealing spectral state transitions typical of black hole X-ray binaries without detecting QPOs.

Contribution

It provides the first detailed spectral state analysis of XTE J1652-453 during its 2009 outburst, identifying state transitions and spectral characteristics.

Findings

Source remained in high/soft state initially

Transitioned to low/hard state later in the outburst

No QPOs were detected throughout the outburst

Abstract

The RXTE and Swift observations on the 2009 outburst from a newly discovered transient and black-hole candidate XTE J1652$-$453 are analyzed. The source was observed by RXTE to behave a sequence of spectral states that are typical to the black hole XRBs. During the first 7 observations, the source is diagnosed to stay in a high/soft state, from the spectrum dominated by soft thermal component which contributes an average of $\sim$ 85% to the X-ray flux at 2-20keV, and from the hardness $\sim$ 0.1 showing up in the hardness-intensity diagram (HID). For the last 20 observations the spectral state is classified as {\sl low/hard} according to an average hardness of $\sim$ 0.8 and a balance between the thermal and the non-thermal components: a power-law component takes ${\geq}80%$ of total 2-20keV flux. Located in between is an {\sl intermediate} state that the source might have experienced. The usual relationship between rms and hardness presents in HRD as well. Throughout the outburst no QPOs are found in XTE J1652$-$453.