Nearby comma low-mass Planck clusters and the extension of scaling relations

In the last several years, tremendous progress from the SZ surveys like Planck,SPT and ACT has made the SZ observation an important means for the studies ofthe ICM and cluster cosmology. While ground SZ telescopes are generally onlysensitive to and are focused on rich clusters, Planck can detect poor clustersand even groups at z<0.05, as shown by the 2013 Planck cluster catalog. Weselect a sample of 26 poor clusters and groups detected by Planck at z<0.05. Sixof them have no XMM or Chandra data and two of these six clusters are not evendetected by RASS. We propose to observe these six systems with XMM to have acomplete sample of Planck lowmass systems to extend the Planck scalingrelations to a mass scale that is 4 5 times lower than what was achieved before. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]