We present the results of a detailed correlation study between the soft X-ray, hard X-ray, and radio emission (obtained from RXTE ASM , BATSE, and GBI observations, respectively) of the bright radio emitting Galactic X-ray binary Cygnus X-3. We detect a very strong positive correlation between the soft X-ray and radio emission during the low-hard and minor flaring periods of the source, and an ...

We show that the prompt and afterglow X-ray emission of GRB060218, as well as its early (t 1 d) optical-UV emission, can be explained by a model in which a radiation-mediated shock propagates through a compact progenitor star into a dense wind. The prompt thermal X-ray emission is produced in this model as the mildly relativistic shock, β ≈ 0.85 carrying few ×10 49 erg, reaches the wind (Thomso...

The prompt γ-ray emission in γ-ray bursts is believed to be produced by internal shocks within a relativistic unsteady outflow. The recent detection of prompt optical emission accompanying the prompt γ-ray emission appears to be inconsistent with this model since the out flowing plasma is expected to be highly optically thick to optical photons. We show here that fluctuations in flow properties...

We have analyzed observations with the Chandra X-ray Observatory of the diffuse emission by hot gas in 7 dwarf starburst galaxies, 6 edge-on starburst galaxies, and 9 Ultra Luminous Infrared Galaxies. These systems cover ranges of ∼ 10 4 in X-ray luminosity and several thousand in star formation rate and K-band luminosity (a proxy for stellar mass). Despite this range in fundamental parameters,...

Context. In the framework of the study of the X-ray and optical emission in supernova remnants we focus on an isolated X-ray knot in the northern rim of the Vela SNR (Vela FilD), whose X-ray emission has been studied and discussed in Paper I. Aims. We aim at understanding the physical origin of the X-ray and optical emission in FilD, at understanding the role of the different physical processes...

On the basis of the full set of reanalyzed Einstein IPC X-ray data on Tau-Aur pre-main-sequence stars, presented in a companion paper, we have studied the relationships between the X-ray emission and typical diagnostics of pre-main-sequence activity, to obtain indications on the origin of the X-ray emission and on the structure of the outer atmospheres in these stars. We argue that, in the case...

Understanding the nature of Extremely Red Objects [EROs; (I − K)≥4] is one of the most challenging issues in observational cosmology. Here we report on the X-ray constraints provided by the 2 Ms Chandra Deep Field-North Survey (CDF-N). X-ray emission has been detected from 11 out of 36 EROs (≈ 30%). Five of these have hard X-ray emission and appear to be obscured AGNs, while non-AGN emission (s...

The diffuse Galactic γ-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory (CGRO) indicated excess γ-ray emission ≥ 1 GeV relative to diffuse Galactic γ-ray emission models consistent with directly measured CR spectra (the so-c...

We report BeppoSAX observations of spatially resolved hard X-ray emission from IC 443, a supernova remnant interacting with a molecular cloud. The emission is shown to come from two localized features spatially correlated with bright molecular emission regions. Both hard X-ray features have soft X-ray counterparts, in one case shifted by 20 toward the remnant interior. The spectra of X-ray emis...