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

We analyse the Rossi X-ray Timing Explorer (RXTE) and Swift observations of the 2009 outburst from a newly discovered transient and black hole candidate XTE J1652−453. The behaviour of the source was observed by RXTE to be a sequence of spectral states that are typical of black-hole X-ray binaries. During the first seven observations, it is determined that the source remains in a high/soft state. This is determined from the spectrum that is dominated by a soft thermal component, which contributes an average of ∼85 per cent to the X-ray flux at 2-20 keV, and from the hardness ∼0.1 showing up in the hardness-intensity diagram. For the last 20 observations, the spectral state is classified as low/hard, according to an average hardness of ∼0.8 and a balance between the thermal and the non-thermal components; a power-law component takes ≥80 per cent of the total 2-20 keV flux. Located in between is an intermediate state that the source might have experienced. The usual relationship between the rms and hardness is also present in the hardness-rms diagram. Throughout the outburst, no quasi-periodic oscillations are found in XTE J1652−453.