Multiwavelength observations of the black hole candidate Swift J1753.5-0127

TL;DR

This study reports multiwavelength observations of the black hole candidate Swift J1753.5-0127, revealing unusual spectral features and faint radio emission during its ongoing outburst in the Low/Hard State.

Contribution

First simultaneous multiwavelength analysis of Swift J1753.5-0127 showing a low-luminosity thermal component and unexpectedly faint radio emission.

Findings

Thermal component detected at very low luminosity.

Radio emission significantly fainter than typical black hole candidates.

Source remains in Low/Hard State during outburst.

Abstract

We present preliminary results from the analysis of simultaneous multiwavelength observations of the black hole candidate Swift J1753.5-0127. The source is still continuing its outburst started in May 2005, never leaving the Low/Hard State. In the X-ray energy spectra we confirm evidence for a thermal component at a very low luminosity possibly extending close to but not at the innermost stable orbit. This is unusual for black hole candidates in the Low/Hard State. Furthermore, we confirm that its radio emission is significantly fainter than expected from the relation observed in other black hole candidates between the observed radio/X-ray fluxes.