Hard and Soft X Rays

Young stellar objects from soft to hard X-rays

Magnetically active stars are the sites of efficient particle acceleration and plasma heating, processes that have been studied in detail in the solar corona. Investigation of such processes in young stellar objects is much more challenging due to various absorption processes. There is, however, evidence for violent magnetic energy release in very young stellar objects. The impact on young stel...

INTEGRAL probes the morphology of the Crab nebula in hard X - rays / soft γ - rays

Aims. We use the IBIS/ISGRI telescope on board INTEGRAL to measure the position of the centroid of the 20-200 keV emission from the Crab region. Methods. We find that the astrometry of the IBIS telescope is affected by the temperature of the IBIS mask during the observation. After correcting for this effect, we show that the systematic errors on the astrometry of the telescope are of the order ...

Orbital Modulation of X-rays from Cygnus X-1 in Its Hard and Soft States

We have analyzed over 2 yr of RXT E/All-Sky Monitor data for Cygnus X-1. We have detected the 5.6 day orbital period in Lomb-Scargle periodograms of both light curves and hardness ratios when Cyg X-1 was in the hard state. This detection was made with improved sensitivity and temporal coverage compared with previous detections by other X-ray missions. The folded light curves and hardness ratios...

Resonant Inelastic X-ray Scattering at the ESRF: Hard and Soft X-rays

Blazars in hard X–rays

Although blazars are thought to emit most of their luminosity in the γ–ray band, there are subclasses of them very prominent in hard X–rays. These are the best candidates to be studied by Simbol–X. They are at the extremes of the blazar sequence, having very small or very high jet powers. The former are the class of TeV emitting BL Lacs, whose synchrotron emission often peaks at tens of keV or ...