Probing warm-hot intergalactic medium associated with the Virgo cluster

The amount of baryons detected at z0 is only about 20% of that detected atzvirgul3, or calculated from the standard bigbang nucleosynthesis. Recentsimulations predict that most of the baryons in the present Universe residein a warmhot intergalactic medium (WHIM) with temperatures of 10**57K,associated with clusters of galaxies. At AO2, we proposed an observationof a quasar behind the Virgo to detect oxygen absorption lines due to theWHIM associated with the cluster. We marginally detected a redshifted OVIIIabsorption line. However, the exposure time was not long enough, and theconfidence level of the absorption line was 96.4%. Hence, we resubmit thisproposal to confirm the absorption line with 5sigma confidence. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]