A failed outburst of H1743-322

TL;DR

This paper reports on a peculiar short outburst of the black hole candidate H1743-322, showing an unusual spectral evolution that deviates from typical black hole transient outburst patterns, confirmed through spectral and timing analysis.

Contribution

It presents the first detailed observation of a failed outburst in H1743-322, highlighting its atypical spectral state transition behavior.

Findings

The outburst only transitions from Hard State to Hard-Intermediate State.

The source's luminosity decreases and spectrum hardens after the transition.

Such failed outbursts are rarely observed in black hole transients.

Abstract

We report on a campaign of X-ray and soft gamma-ray observations of the black hole candidate H 1743-322 (also named IGR J17464-3213), performed with the RXTE, INTEGRAL and Swift satellites. The source was observed during a short outburst between 2008 October 03 and 2008 November 16. The evolution of the hardness-intensity diagram throughout the outburst is peculiar, in that it does not follow the canonical pattern through all the spectral states (the so called q-track pattern) seen during the outburst of black-hole transients. On the contrary, the source only makes a transition from the Hard State to the Hard-Intermediate State. After this transition, the source decreases in luminosity and its spectrum hardens again. This behaviour is confirmed both by spectral and timing analysis. This kind of outburst has been rarely observed before in a transient black hole candidate.