Bibcode
Cadolle Bel, M.; Rodriguez, J.; D'Avanzo, P.; Russell, D. M.; Tomsick, J.; Corbel, S.; Lewis, F. W.; Rahoui, F.; Buxton, M.; Goldoni, P.; Kuulkers, E.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 534, id.A119
Advertised on:
10
2011
Revista
Número de citas
44
Número de citas referidas
42
Descripción
Context. The microquasar GX 339-4 experienced a new outburst in 2010: it
was observed simultaneously at various wavelengths from radio up to soft
γ-rays. We focus on observations that are quasi-simultaneous with
those made with the INTEGRAL and RXTE satellites: these were collected
in 2010 March-April during our INTEGRAL target of opportunity programme,
and during some of the other INTEGRAL observing programmes with GX 339-4
in the field-of-view. Aims: X-ray transients are extreme systems
that often harbour a black hole, and are known to emit throughout the
whole electromagnetic spectrum when in outburst. The goals of our
programme are to understand the evolution of the physical processes
close to the black hole and to study the connections between the
accretion and ejection. Methods: We analysed radio, NIR, optical,
UV, X-ray and soft γ-ray observations. We studied the source
evolution in detail by producing light curves, hardness-intensity
diagrams and spectra. We fitted the broadband data with
phenomenological, then physical, models to study the emission coming
from the distinct components. Results: Based on the energy
spectra, the source evolved from the canonical hard state to the
canonical soft state. The source showed X-ray spectral variations that
were correlated with changes in radio, NIR and optical emission. The
bolometric flux increased from 0.8 to 2.9 × 10-8 erg
cm-2 s-1 while the relative flux and contribution
of the hot medium decreased on the average. Reprocessing in the disc was
likely to be strong at the end of our observations. Conclusions:
The source showed a behaviour similar to that of previous outbursts,
with some small deviations in the hard X-ray parameter evolution. The
radio, NIR and optical emission from jets was detected and observed to
fade as the source softened. The results are discussed within the
context of disc and jet models.