GX 339--4 is a well-known microquasar. In this contribution we show the obtained results with the INTEGRAL and XMM-Newton observatories of the outburst undertaken on 2007. The observations cover spectral evolution from the hard, soft intermediate sta
tes to the high/soft state. Spectral hardening correlated with the appearance of an skewed Fe line is detected during one of the observations during the soft intermediate state. In all spectral states joint XMM/EPIC-pn, JEM-X, ISGRI and SPI data were fit with the hybrid thermal/non-thermal Comptonization model (EQPAIR). With this model a non-thermal component seems to be required by the data in all the observations. Our results imply evolution in the coronal properties, the most important one being the transition from a compact corona in the first observation to the disappearance of coronal material in the second and re-appearance in the third. We discuss the results obtained in the context of possible physical scenarios for the origin and geometry of the corona and its relation to black hole states.
We present simultaneous XMM-Newton and INTEGRAL observations of the luminous black hole transient and relativistic jet source GX 339-4. GX 339-4 started an outburst on November of 2006 and our observations were undertaken from January to March of 200
7. We triggered five INTEGRAL and three XMM-Newton target of Opportunity observations within this period. Our data cover different spectral states, namely Hard Intermediate, Soft Intermediate and High/Soft. We performed spectral analysis to the data with both phenomenological and more physical models and find that a non-thermal component seems to be required by the data in all the observations. We find a hardening of the spectrum in the third observation coincident with appearance of a broad and skewed Fe K alpha line. In all spectral states joint XMM/EPIC-pn,JEM-X, ISGRI and SPI data were fit with the hybrid thermal/non-thermal Comptonization model (EQPAIR). While this model accounts very well for the high/energy emission observed, it has several drawbacks in the description of the lower energy channels. Our results imply evolution in the coronal properties, the most important one being the transition from a compact corona in the first observation to the disappearance of coronal material in the second and re-appearance in the third. This fact, accompanied by the plasma ejection events detected in radio on February 4 to 18, suggest that the ejected medium is the coronal material responsible for the hard X-ray emission.
