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K. E. Whitaker (University of Massachusetts/Amherst), R. P. Kraft, J. Posson-Brown, C. Jones, R. H. Donnelly (Harvard/Smithsonian Center for Astrophysics)
We present preliminary results from the analysis of a 29 ks XMM/Newton observation of the nearby cluster of galaxies A119. The primary goal of this study was to investigate the ongoing merger that had been suggested on the basis of previous ROSAT and ASCA observations. We have measured the gas temperature, the radial surface brightness profile, and have created temperature maps of the ICM. The average temperature of the cluster gas is 6.0±0.5 keV, although there is a long, cool (kBT=4.4±0.4) filament to the N/NE of the central region that is apparent in both the surface brightness and temperature maps. This structure demonstrates that A119 is undergoing a merger. The morphology of the cool region suggests that material is infalling into the cluster along a relatively narrow tube, reminiscent of the filamentary structures seen in simulations of the formation of large scale structure in the Universe. Away from this filament, the surface brightness profile of the gas is well fit by an isothermal \beta-model with \beta=0.67±0.06. The total gravitating mass and baryon fraction within 0.73 Mpc are 3.8\times1015 M\odot and 0.083, respectively. The background during this observation was higher and spectrally harder than the nominal XMM/Newton blank sky background. Our analysis procedures to remove this excess background are discussed. This work was supported by the SAO REU intern program (NSF grant AST-9731923), the {\em Chandra} X-ray Center (NASA grant NAS8-39073), and the {\em Chandra} HRC (NASA grant NAS8-38248).
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.