2013MNRAS.429.2727S

We examine the velocity width of cool X-ray emitting material using XMM-Newton Reflection Grating Spectrometer (RGS) spectra of a sample of clusters and group of galaxies and elliptical galaxies. Improving on our previous analyses, we apply a spectral model which accounts for broadening due to the spatial extent of the source. With both conventional and Markov Chain Monte Carlo approaches we obtain limits, or in a few cases measurements, of the velocity broadening of the coolest X-ray material. In our sample, we include new observations targeting objects with compact, bright, line-rich cores. One of these, MACSJ2229.7-2755, gives a velocity limit of 280 km s^-1  at the 90per cent confidence level. Other systems with limits close to 300 km s^-1  include A1835, NGC4261 and NGC4472. For more than a third of the targets we find limits better than 500 km s^-1 . HCG62, NGC1399 and A3112 show evidence for ∼ 400  km s^-1  velocity broadening. For a smaller sample of objects, we use continuum-subtracted emission line surface brightness profiles to account for the spatial broadening. Although there are significant systematic errors associated with the technique (∼ 150  km s^-1 ), we find broadening at the level of 280 to 500 km s^-1  in A3112, NGC1399 and NGC4636.