Related papers: Peculiar properties of 2 unusually X-ray bright ea…
We use the extensive public archive of ROSAT High Resolution Imager (HRI) observations to carry out a statistical investigation of the X-ray properties of nearby galaxies. Specifically we focus on the sample of 486 bright (B_T < 12.5)…
Statistical properties of X-ray luminosity and temperature are studied for 52 early-type galaxies based on the ROSAT PSPC data. All of the X-ray luminous galaxies show largely extended emission with a radius of a few times of 10$r_e$, while…
Hubble Space Telescope observations revealed that the central surface brightness profiles of early type galaxies can be divided into two types: "core" profiles and featureless power law profiles. On the basis of this and previous results,…
A ROSAT HRI X-ray image was obtained of the open globular cluster NGC 288, which is located near the South Galactic Pole. This is the first deep X-ray image of this system. We detect a Low Luminosity Globular Cluster X-ray source (LLGCX)…
The nearby barred spiral galaxy NGC 1672 is thought to have a weak Seyfert nucleus in addition to its strong starburst activity. Observations with the PSPC and HRI instruments on board the ROSAT X-ray satellite show that three X-ray sources…
We discuss ROSAT HRI X-ray observations of 33 very nearby galaxies, sensitive to X-ray sources down to a luminosity of approximately 10^38 erg/s. The galaxies are selected from a complete, volume limited sample of 46 galaxies with d<7 Mpc…
Our 5 ks Chandra ACIS-S observation of the globular cluster NGC 6652 detected 7 X-ray sources, 3 of which are previously unidentified. This cluster hosts a well-known bright low-mass X-ray binary, source A (or XB 1832-330). Source B shows…
Massive halos of hot plasma exist around some, but not all elliptical galaxies. There is evidence that this is related to the age of the galaxy. In this paper new X-ray observations are presented for three early-type galaxies that show…
The X-ray colors and X-ray-to-optical luminosity ratios (L_X/L_B) of 61 early- type galaxies observed with the ROSAT PSPC are determined. The colors indicate that the X-ray spectral properties of galaxies vary as a function of L_X/L_B. The…
The advanced capabilities of the Chandra and XMM-Newton observatories mean that, for the first time, the detailed study of the brightest point-like X-ray sources in nearby galaxies outside of the local group is a realistic aim. Here, we…
We present an investigation of the X-ray properties of 13 LINERs based on ROSAT all-sky survey and pointed PSPC and HRI observations. Several sources are studied for the first time in X-rays. The X-ray spectra are best described by a…
We present a spectral and spatial analysis of the nuclear and circumnuclear X-ray emission of the prominent southern starburst/Seyfert galaxy NGC 1365. To describe the X-ray spectrum of the core source, we favour a two-component model…
We use ROSAT PSPC data to study the X-ray properties of a sample of twelve poor groups that have extensive membership information (Zabludoff and Mulchaey 1997; Paper I). Diffuse X-ray emission is detected in nine of these groups. In all but…
Recent hard X-ray surveys have proven to be effective in discovering large numbers of X-ray sources that, despite the likely association with active nuclei, appear to be characterized by "peculiar" properties. Among these "exotic" source…
NGC 3079 is a very active, disturbed galaxy which has been observed to have X-ray and radio ejections from it as well as an optical superbubble along its minor axis. Here we show that the brightest X-ray sources within about 40 arcmin are…
We present the study of three bright Early-Type galaxies hosted in groups or poor clusters: NGC 1399, NGC 1404 and NGC 507. We used ROSAT HRI, PSPC and, when available, higher resolution Chandra data to study the structure of the X-ray…
We have undertaken a multiwavelength project to study the relatively unknown properties of groups and poor clusters of galaxies at intermediate redshifts. In this paper, we describe the XMM-Newton observations of six X-ray selected groups…
We present the results of the analysis of the ROSAT PSPC pointed observation of the S0 galaxy NGC5866. Previous Einstein observations had revealed that this galaxy has a low X-ray to optical ratio Lx/Lb. Theoretical models of the X-ra…
We briefly review and extend our discussion of the ROSAT detection of the extraordinarily luminous (> 10^{42} erg/s) partly extended (> 30 kpc diameter) X-ray emission from the ultraluminous infrared galaxy NGC 6240. The `standard'-model of…
We present results from the cross-correlation of the spectroscopic atlas of Ho etal (1995) with the ROSAT All-Sky Survey Bright Source Catalogue, in an attempt to understand the X-ray emission mechanisms in nearby galaxies. The resulting…