A bright X-ray transient in M31 was detected in a 5000-sec Chandra ACIS-I observation on 2001 Aug 31.54 UT. The new transient (CXOU J004305.5+411703) is located...
On Nov 19, 2001, The Chandra X-ray Observatory surveyed M31 with 5 overlapping very short (1ks) HRC exposures and a single short (5ks) ACIS-S exposure...
Active galactic nuclei (AGN) are powered by energetic phenomena which cannot be attributed to stars. LINERs appears to be the low power end of the AGN sequence...
One of the most important features in active galactic nuclei (AGN) is the variability of their emission. Variability has been discovered at X-ray, UV, and radio...
Active galactic nuclei (AGN) are powered by energetic phenomena which cannot be attributed to stars. Among AGN, several objects can be described by the unified...
We have performed a uniform analysis of the power spectrum densities (PSDs) of 104 nearby (z ~= 2 × 10-4 Hz. Only KUG 1031+398 (RE J1034+396) shows evidence for...
X-ray variability of 104 active galactic nuclei. XMM-Newton power-spectrum density profiles
Active galactic nuclei (AGN), powered by accretion onto supermassive black holes (SMBHs), are thought to be scaled up versions of Galactic black hole X-ray...
X-shaped radio galaxies: their black hole masses and starburst histories
A recent merger of two supermassive black holes (BH) or the presence of a second active BH in the galactic nucleus are two of the main scenarios proposed to...