Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2009-09-14
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
10 pages, 4 figures, accepted for publication by MNRAS
Scientific paper
In this Paper we report on radio (VLA and ATCA) and X-ray (RXTE, Chandra and Swift) observations of the outburst decay of the transient black hole candidate H1743-322 in early 2008. We find that the X-ray light curve followed an exponential decay, leveling off towards its quiescent level. The exponential decay timescale is ~4 days and the quiescent flux corresponds to a luminosity of 3x10^32 (d/7.5 kpc)^2 erg/s. This together with the relation between quiescent X-ray luminosity and orbital period reported in the literature suggests that H1743-322 has an orbital period longer than ~10 hours. Both the radio and X-ray light curve show evidence for flares. The radio - X-ray correlation can be well described by a power-law with index ~0.18. This is much lower than the index of 0.6-0.7 found for the decay of several black hole transients before. The radio spectral index measured during one of the radio flares while the source is in the low-hard state, is -0.5+-0.15, which indicates that the radio emission is optically thin. This is unlike what has been found before in black hole sources in the low-hard state. We attribute the radio flares and the low index for the radio - X-ray correlation to the presence of shocks downstream the jet flow, triggered by ejection events earlier in the outburst. We find no evidence for a change in X-ray power law spectral index during the decay, although the relatively high extinction of N_H =2.3x10^22 cm^-2 limits the detected number of soft photons and thus the accuracy of the spectral fits.
Fender Rob P.
Gallo Elena
Homan Jeroen
Jonker Peter G.
Kaaret Phil
No associations
LandOfFree
Following the 2008 outburst decay of the black hole candidate H1743-322 in X-ray and radio does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Following the 2008 outburst decay of the black hole candidate H1743-322 in X-ray and radio, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Following the 2008 outburst decay of the black hole candidate H1743-322 in X-ray and radio will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-565562