Giuseppina Fabbiano

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We have analyzed an XMM-Newton observation of the nearby spiral galaxy NGC 1313, which contains two “ultra-luminous” X-ray (ULX) sources. We measure isotropic luminosities of LX = 2.0× 1040 erg s−1 and LX = 6.6× 1039 erg s−1 for NGC 1313 X-1 and X-2 (0.2-10.0 keV, assuming a distance of 3.7 Mpc). The spectra statistically require soft and hard spectral(More)
We present an occultation of the central X-ray emitting region in the Seyfert Galaxy NGC 1365. This extreme spectral variation (from Compton-thin to reflection-dominated and back to Compton-thin in four days) has been caught in a ten days Chandra monitoring campaign consisting of six short (15 ks) observations performed every two days. We discuss the(More)
This is the second of two papers based on a systematic multi-wavelength (X, B, H, 12μm, FIR, 6cm) statistical analysis of the Einstein Observatory Galaxy Catalog sample of 234 ‘normal’ S0/a-Irr galaxies. This sample is representative of spiral galaxies (Paper I), and its wide wavelength coverage provides a unique opportunity for a systematic exploration of(More)
Today’s sensitive, high-resolution X-ray observations allow the study of populations of X-ray sources, in the luminosity range of Galactic X-ray binaries, in galaxies as distant as 20-30Mpc. The traditional astronomical tools of photometric diagrams and luminosity functions are now applied to these populations, providing a direct probe of the evolved binary(More)
Software development for the Chandra X-ray Center Data System began in the mid 1990’s, and the waterfall model of development was mandated by our documents. Although we initially tried this approach, we found that a process with elements of the spiral model worked better in our science-based environment. High-level science requirements are usually(More)
The relatively nearby (distance=24.1 Mpc) elliptical galaxy NGC821 hosts an extreme example of a quiescent central massive black hole, for which deep Chandra observations revealed a nuclear source for the first time (with L2−10keV/LEdd ∼ 3.6×10 ). We present here a multiwavelength study of this nucleus, including VLA observations that detect a radio(More)
We investigate models for the class of ultraluminous non–nuclear X–ray sources (ULXs) seen in a number of galaxies and probably associated with star–forming regions. Models where the X–ray emission is assumed to be isotropic run into several difficulties. In particular formation of sufficient numbers of the required ultramassive black–hole X–ray binaries is(More)
The new frontier in astrophysics is the study of the very first stars, galaxies and black holes in the early Universe. These objects are beyond the grasp of the current generation of X-ray telescopes such as Chandra, and so the Generation-X Vision Mission has been proposed as an X-ray observatory which will be capable of detecting these earliest objects.(More)