The broad band X-ray spectrum of the black hole candidate GRS1758-258

Abstract

We present the results of a BeppoSAX observation of the black hole candidate GRS1758-258 carried out in 1997, while the source was in its low/hard state. The X-ray spectrum, simultaneously observed over the broad energy range from 0.1 to 200 keV, can be well described by a Comptonized emission model with electron temperature kT_e = 31.4 keV and optical depth of 4.0 (spherical geometry), although a cut-off power-law and a reflection model cannot be excluded. Additionally, a broad iron line at 6.4 keV with equivalent width EW = 67 eV has been marginally detected. The 0.1-200 keV luminosity is 1.4x10^37 erg/s for an assumed distance of 8 kpc. The soft and hard luminosities are such that the source falls inside the so-called "burster box". No evidence for a soft excess is present.

accepted for publication in Astronomy and Astrophysics

References in corpus (3)

• A Transition to the Soft State in GRS 1758-258
• Deep Infrared Imaging of the Microquasars 1E1740-2942 and GRS 1758-258
• Long-term Multi-wavelength Observations of GRS 1758-258 and the ADAF Model

Cited by in corpus (6)

• A unified accretion-ejection paradigm for Black Hole X-ray Binaries
• INTEGRAL and RXTE monitoring of GRS 1758-258 in 2003 and 2004. A transition from the dim soft state to the hard state
• Hard X-ray/Soft gamma-ray experiments and missions: overview and prospects
• Suzaku Observations of the Galactic Center Microquasar 1E 1740.7-2942
• Broadband X-ray properties of black holes GRS 1758-258 and 1E 1740.7-2942: AstroSat and NuSTAR results
• Broadband X-ray Spectroscopy and Estimation of Spin of the Galactic Black Hole Candidate GRS 1758-258