An XMM-Newton study of the RGH 80 galaxy group

Abstract

We present an X-ray study of the galaxy group RGH 80, observed by XMM-Newton. The X-ray emission of the gas is detected out to ∼462 h 50N-1 kpc, corresponding to ∼0.45r200 The group is relatively gas rich and luminous with respect to its temperature of 1.01 ± 0.01 keV. Using the deprojected spectral analysis, we find that the temperature peaks at ∼1.3 keV around 0.11r200, and then decreases inwards to 0.83 keV at the center and outwards to ∼70% of the peak value at large radii. Within the central ∼60 kpc of the group where the gas cooling time is less than the Hubble time, a two-temperature model with temperatures of 0.82 and 1.51 keV and the Galactic absorption gives the best fit of the spectra, with ∼20% volume occupied by the cool component. We also derive the gas entropy distribution, which is consistent with the prediction of cooling and/or internal heating models. Furthermore, the abundances of O, Mg, Si, S and Fe decrease monotonically with radius. With the observed abundance ratio pattern, we estimate that ∼85% or ∼72% of the iron mass is contributed by SN la, depending on the adopted SN II models.