ar X iv : a st ro - p h / 06 03 69 7 v 1 2 7 M ar 2 00 6 The low - luminosity galaxy population in the NGC 5044 Group Sergio

ar X iv : a st ro - p h / 01 03 15 7 v 1 1 1 M ar 2 00 1 Population of X - ray binaries and the dynamical history of their host galaxies

The observed luminosity distributions of X-ray sources suggest the presence of several populations of X-ray binaries in the nearby galaxies. Each population probably has a different formation and evolutionary history, depending on the intrinsic properties of the sources and the host environment. The features seen in the Log N (> S) – Log S plots for different galactic components and for differe...

ar X iv : a st ro - p h / 98 06 15 8 v 1 1 1 Ju n 19 98 Low - luminosity X - ray Active Nuclei in S 0 galaxies NGC 3065 and NGC 4203

We present ASCA X-ray results on two S0 galaxies, NGC 3065 and NGC 4203. In both galaxies, we detected hard X-ray emission from a point-like source at the nucleus. Single power law model having a photon index of ∼1.8 well described the spectra of these sources, while thin thermal emission which is common in S0 galaxies was not detected. The 2–10 keV luminosities of these nuclear sources, 2.2×10...

ar X iv : a st ro - p h / 03 05 49 9 v 1 2 7 M ay 2 00 3 Discovery of Bright Variable X - ray Sources in NGC 1569 with Chandra

From the analysis of a ∼100 ks Chandra observation of the dwarf starburst galaxy NGC 1569, we have found that the X-ray point sources, CXOU 043048.1+645050 and CXOU 043048.6+645058, showed significant time variability. During this observation, the X-ray flux of CXOU 043048.1+645050 increased by 10 times in only 2 × 10 s. Since the spectrum in its bright phase was fitted with a disk blackbody mo...

ar X iv : a st ro - p h / 01 03 25 4 v 1 1 6 M ar 2 00 1 Construction of the Variability → Luminosity Estimator

ar X iv : a st ro - p h / 02 03 45 4 v 2 1 7 M ay 2 00 2 New Members of the Cluster Family in Nearby Lenticulars

Using spectra obtained with the Keck I telescope we have demonstrated conclusively that the faint (23≤V≤ 24 mag.) and unusually extended objects we discovered in HST images of the lenticular galaxies, NGC 1023 and NGC 3384, are star clusters associated with their respective galaxies. In the case of NGC 1023 we were further able to establish that these objects are old (≥7–8 Gyr), moderately meta...