Unveiling bulk motions in hot gaseous halo of a giant elliptical galaxy

A key missing piece in our understanding of AGN feedback and evolution ofmassive galaxies is the velocity structure within their hot gaseous halos. Wepropose a deep 530 ks observation of NGC 5813, a nearby, Xray bright, massivegalaxy. Combined with the archival data, we will use the first and second orderRGS spectra to disentangle redshifts of two temperature components present inthe gas from their spatial offsets. This will provide the first measurements ofbulk velocities of multiple gas temperature components in a galaxy halo, openinga new window onto study gas dynamics and AGN feedback with RGS. Until Athena,RGS will be the only instrument with sufficient spectral and spatial resolutionto probe hot gas motions on the r^ant, b?<kpc scales. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]