Aims. We present a uniform catalog of the images and radial profiles of the temperature, abundance, and brightness for 70 clusters of galaxies observed by XMM-Newton. Methods. We use a new "first principles" approach to the modeling and removal of the background components; the quiescent particle background, the cosmic diffuse emission, the soft proton contamination, and the solar wind charge exchange emission. Each of the background components demonstrate significant spectral variability, several have spatial distributions that are not described by the photon vignetting function, and all except for the cosmic diffuse emission are temporally variable. Because these backgrounds strongly affect the analysis of low surface brightness objects, we provide a detailed description our methods of identification, characterization, and removal. Results. We have applied these methods to a large collection of XMM-Newton observations of clusters of galaxies and present the resulting catalog. We find significant systematic differences between the Chandra and XMM-Newton temperatures.

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The soft X-ray background in the 0.1-1.0 keV band is known to be produced by at least three sources; the Local Hot Bubble (LHB), the extragalactic power law (EPL), and a seemingly galactic component that lies outside the bulk of the absorption that is due to the ISM of the spectral energy distribution significantly better than single-component models, and is consistent with both angular variation and spectral constraints.

Context. To analyze diffuse emission that fills the field of view, one must accurately characterize the instrumental backgrounds. For the XMM-Newton EPIC-MOS instrument these backgrounds include a temporally variable "quiescent" component, as well as the strongly variable soft proton contamination. Aims. We have characterized the spectral and spatial response of the EPIC-MOS detectors to these background components and have developed tools to remove these backgrounds from observations. Methods. The "quiescent" component was characterized using a combination of the filter-wheel-closed data and a database of unexposed-region data. The soft proton contamination was characterized by differencing images and spectra taken during flared and flare-free intervals. Results. After application of our modeled backgrounds, the differences between independent observations of the same region of blank sky are consistent with the statistical uncertainties except when there is clear spectral evidence of solar wind charge exchange emission. Using a large sample of blank sky data, we show that strong magnetospheric SWCX emission requires elevated solar wind fluxes; observations through the densest part of the magnetosheath are not necessarily strongly contaminated with SWCX emission.Key words. methods: data analysis -instrumentation: detectors -X-rays: general MotivationAlthough XMM-Newton has a large field of view (FOV) compared to other current X-ray observatories, there are often observations in which the object of interest (such as diffuse Galactic emission, nearby galaxies, or a large cluster of galaxies) fills the entire FOV. Determining the background in such a situation can be problematic. The non-cosmic background is due primarily to energetic particles interacting directly with the detector, or interacting with material around the detector and producing fluorescent X-rays that then strike the detector. This "particleinduced background" has multiple components and each component is temporally variable, although on different scales. Since the particle background is temporally variable, using the particle background derived from another observation is likely to be unsatisfactory."Blank sky" observations are often used to subtract a spectrum combining the particle background and the Galactic emission to allow the measurement of the spectrum of clusters of galaxies. Given that the Galactic background varies strongly with Galactic coordinate, use of blank sky data to remove the particle background and Galactic foreground emission in order to study some other object requires evaluation of the suitability of each blank sky field for its appropriateness based on two criteria: the Galactic spectrum and the particle background spectrum. This method works well at E > 2 keV where neither the bulk of the Galaxy (away from the Galactic center and plane) nor the particle background varies greatly, but is much more Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly fun...

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We have obtained a series of deep X-ray images of the nearby galaxy M83 using Chandra, with a total exposure of 729 ks. Combining the new data with earlier archival observations totaling 61 ks, we find 378 point sources within the D 25 contour of the galaxy. We find 80 more sources, mostly background active galactic nuclei (AGNs), outside of the D 25 contour. Of the X-ray sources, 47 have been detected in a new radio survey of M83 obtained using the Australia Telescope Compact Array. Of the X-ray sources, at least 87 seem likely to be supernova remnants (SNRs), based on a combination of their properties in X-rays and at other wavelengths. We attempt to classify the point source population of M83 through a combination of spectral and temporal analysis. As part of this effort, we carry out an initial spectral analysis of the 29 brightest X-ray sources. The soft X-ray sources in the disk, many of which are SNRs, are associated with the spiral arms, while the harder X-ray sources, mostly X-ray binaries (XRBs), do not appear to be. After eliminating AGNs, foreground stars, and identified SNRs from the sample, we construct the cumulative luminosity function (CLF) of XRBs brighter than 8 × 10 35 erg s −1. Despite M83's relatively high star formation rate, the CLF indicates that most of the XRBs in the disk are low mass XRBs.

A deep (98.2 ks) Chandra Cycle-1 observation has revealed a wealth of discrete X-ray sources as well as diffuse emission in the nearby face-on spiral galaxy M101. From this rich dataset we have created a catalog of the 110 sources from the S3 chip detected with a significance of > 3σ. This detection threshold corresponds to a flux of ∼ 10 −16 ergs cm −2 s −1 and a luminosity of ∼ 10 36 ergs s −1 for a distance to M101 of 7.2 Mpc. The sources display a distinct correlation with the spiral arms of M101 and include a variety of X-ray binaries, supersoft sources, supernova remnants, and other objects of which only ∼ 27 are likely to be background sources. There are only a few sources in the interarm regions, and most of these have X-ray colors consistent with that of background AGNs. The derived log N −log S relation for the sources in M101 (background subtracted) has a slope of −0.80 ± 0.05 over the range of 10 36 − 10 38 ergs s −1 . The nucleus is resolved into 2 nearly identical X-ray sources, each with a 0.5 -2.0 keV flux of 4 × 10 37 ergs s −1 . One of these sources coincides with the optical nucleus, and the other coincides with a cluster of stars 110 pc to the south. The field includes 54 optically identified SNR, of which 12 are detected by Chandra. Two of the SNR sources are variable and hence must be compact objects. In total, 8 of the X-ray sources show evidence for short term temporal variation during this observation. Two of these variable sources are now brighter than the ROSAT detection threshold, but they were not detected in the previous ROSAT observations taken in 1992 and 1996. There are also 2 variable sources previously seen with ROSAT that apparently have faded below the Chandra detection threshold. The brightest