Long-Term Monitoring of the Black Hole Candidate Swift J1753.5-0127 with INTEGRAL/SPI

Understand

The black hole candidate Swift J1753.5-0127 went into outburst in 2005 June.

• Rather than fade into quiescence as most black-hole-candidate transients do, it has remained in a low hard spectral state for most of the $\sim$ 9 years after outburst.
• The persistent emission while in a hard state is reminiscent of the black hole Cyg X-1 and the black hole candidates 1E 1740.7-2942 and GRS 1758-258.
• Thus far hard X-ray/soft gamma-ray results have focused mainly on the 2005 flare, with a few additional observations during 2007.