DISCOVERY OF 0.5 MK GAS IN THE CENTER OF THE VIRGO CLUSTER

An observation of M87, the central galaxy of the Virgo Cluster, was pe rformed by the deep survey telescope aboard the Extreme-Ultraviolet Ex plorer, in the 0.065-0.245 keV energy band. A point source and an exte nded emission halo of radius similar to 20' are clearly visible in the data, and represent the first detection of cluster gas emission in th e EUV. The emission cannot be explained by the well-known cluster gas at X-ray temperatures. Instead, it is necessary to introduce a second gas component, with temperature between 5 x 10(5) and 10(6) K. The rap id cooling of plasmas at such temperatures implies a mass accretion ra te of more than 300 M(circle dot) yr(-1). It is unlikely that the phen omenon is directly related to a cooling flow, which involves a much lo wer accretion rate of similar to 10 M(circle dot) yr(-1)