J/MNRAS/457/4515 X-ray_peak-BCG offset for PSZ1 clusters (Rossetti+, 2016) ================================================================================ Measuring the dynamical state of Planck SZ-selected clusters: X-ray peak - BCG offset. Rossetti M., Gastaldello F., Ferioli G., Bersanelli M., De Grandi S., Eckert D., Ghizzardi S., Maino D., Molendi S. =2016MNRAS.457.4515R (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Clusters, galaxy ; X-ray sources Keywords: galaxies: clusters: general - galaxies: clusters: intracluster medium Abstract: We want to characterize the dynamical state of galaxy clusters detected with the Sunyaev-Zeldovich (SZ) effect by Planck and compare them with the dynamical state of clusters selected in X-rays survey. We analysed a representative subsample of the Planck SZ catalogue, containing the 132 clusters with the highest signal to noise ratio and characterize their dynamical state using as an indicator the projected offset between the peak of the X-ray emission and the position of the Brightest cluster galaxy. We compare the distribution of this indicator for the Planck SZ-selected sample and three X-ray-selected samples (HIFLUGCS, MACS and REXCESS). The distributions are significantly different and the fraction of relaxed objects is smaller in the Planck sample (52+/-4 per cent) than in X-ray samples (~=74 per cent) We interpret this result as an indication of different selection effects affecting X-rays (e.g. 'cool core bias') and SZ surveys of galaxy clusters. Description: The starting point of our analysis is the Planck cosmology sample (PSZ1-cosmo) described in Planck Collaboration XX (2014A&A...571A..20P). It is a high-purity subsample constructed from the first release of the Planck catalogue of SZ sources (Planck Collaboration XXIX, 2014A&A...571A..29P, Cat. VIII/91), by imposing a signal-to-noise ratio (S/N) threshold of 7 and applying a mask, that excludes the galactic plane and point sources leaving 65 per cent of the sky for the survey. It contains 189 bona fide clusters with associated redshifts and has been used for the cosmological analysis with cluster number counts described in Planck Collaboration XX (2014A&A...571A..20P). File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 128 132 Properties of the clusters in our sample refs.dat 76 28 References -------------------------------------------------------------------------------- See also: VIII/91 : Planck Catalog of Compact Sources Release 1 (Planck, 2013) J/A+A/581/A14 : Updated Planck catalogue PSZ1 (Planck+, 2015) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 I4 --- Index Index in the PSZ1 catalogue 6- 9 A4 --- --- [PSZ1] 11- 23 A13 --- PSZ1 PSZ1 designation (GLLL.ll+BB.bb) 25- 41 A17 --- AName Alternative name 43- 48 F6.4 --- z Redshift of the cluster 50- 57 F8.4 deg RAdeg X-ray peak right ascension (J2000) 59- 66 F8.4 deg DEdeg X-ray peak declination (J2000) 68- 75 F8.4 deg RABdeg BCG right ascension (J2000) 78- 85 F8.4 deg DEBdeg BCG peak declination (J2000) 88-100 A13 --- Ref Reference we used to associate a BCG to each cluster, in refs.dat file 102-106 F5.2 arcmin theta500 Angular scale corresponding to R_500_ 108-114 F7.2 arcsec DX-BCGa Distance between X-ray peak and BCG in arcsec 116-122 F7.2 kpc DX-BCGk Distance between X-ray peak and BCG in kpc 123-128 F6.2 --- DX-BCGR Distance between X-ray peak and BCG in 0.01R_500_ unit -------------------------------------------------------------------------------- Byte-by-byte Description of file: refs.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 13 A13 --- Ref Reference code 15- 33 A19 --- BibCode BibCode 35- 51 A17 --- Aut Author's name 56- 76 A21 --- Com Comments -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 24-Nov-2016