Abstract
We report high-energy results obtained with INTEGRAL and Rossi-XTE on two microquasars: The persistent high-mass system Cygnus X-1 and the transient low-mass binary SWIFT J1753.5- 0127. INTEGRAL observed Cygnus X-1 from 2002 to 2004: The spectral (5-1000 keV) properties of the source, seen at least in three distinct spectral states, show disc and corona changes. In 2003 June, a high-energy tail at several hundred keV in excess of the thermal Comptonization model was observed, suggesting the presence of an additional non-thermal component. At that time, we detected an unusual correlation between radio data and high-energy hardness. We also report and compare the results obtained with simultaneous observations of the transient source SWIFT J1753.5-0127 performed with Rossi-XTE, INTEGRAL, VLA, REM and NTT on 2005 August 10-12 near its hard X-ray outburst. Broad-band spectra and fast time-variability properties are derived on this source (probably located in the galactic halo) together with radio, IR and optical data. We build a spectral energy distribution of the source and derive interesting multiwavelength constraints. Significantly detected up to 600 keV in a typical Low/Hard State, the transient does not seem to follow the usual radio/X-ray correlation.
| Original language | English |
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| Journal | International Conference Recent Advances in Natural Language Processing, RANLP |
| Publication status | Published - 1 Jan 2006 |
| Externally published | Yes |
| Event | 6th Microquasar Workshop: Microquasars and Beyond, MQW 2006 - Como, Italy Duration: 18 Sept 2006 → 22 Sept 2006 |