J/MNRAS/458/226 MeSsI low-redshift merging cluster sample (de los Rios+, 2016) ================================================================================ The MeSsI (merging systems identification) algorithm and catalogue. de los Rios M., Dominguez M.J.R., Paz D., Merchan M. =2016MNRAS.458..226D (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: Clusters, galaxy ; Morphology Keywords: galaxies: clusters: general- galaxies: kinematics and dynamics - dark matter Abstract: Merging galaxy systems provide observational evidence of the existence of dark matter and constraints on its properties. Therefore, statistically uniform samples of merging systems would be a powerful tool for several studies. In this paper, we present a new methodology for the identification of merging systems and the results of its application to galaxy redshift surveys. We use as a starting point a mock catalogue of galaxy systems, identified using friends-of-friends algorithms, that have experienced a major merger, as indicated by its merger tree. By applying machine learning techniques in this training sample, and using several features computed from the observable properties of galaxy members, it is possible to select galaxy groups that have a high probability of having experienced a major merger. Next, we apply a mixture of Gaussian techniques on galaxy members in order to reconstruct the properties of the haloes involved in such mergers. This methodology provides a highly reliable sample of merging systems with low contamination and precisely recovered properties. We apply our techniques to samples of galaxy systems obtained from the Sloan Digital Sky Survey Data Release 7, the Wide-Field Nearby Galaxy-Cluster Survey (WINGS) and the Hectospec Cluster Survey (HeCS). Our results recover previously known merging systems and provide several new candidates. We present their measured properties and discuss future analysis on current and forthcoming samples. Description: We construct mock catalogues of the SDSS-DR7 redshift survey based on the results of a semi-analytical model (Guo et al. 2011MNRAS.413..101G) and we use it to calibrate our identification method for merging systems. Here we present the low-redshift merging cluster sample, including the properties of the two main substructures identified by our algorithm. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 128 31 Low-redshift merging cluster sample, including the properties of the two main substructures identified by our algorithm. -------------------------------------------------------------------------------- See also: J/A+A/514/A102 : SDSS DR7 groups of galaxies (Tago+, 2010) J/MNRAS/418/1409 : Compact groups of galaxies in SDSS DR7 (Mendel+, 2011) J/MNRAS/422/25 : SDSS DR7 groups, clusters and filaments (Smith+, 2012) J/ApJ/799/95 : Structure in 3D galaxy distribution. II. Voids (Way+, 2015) J/A+A/588/A14 : Friends-of-friends galaxy group finder (Tempel+, 2016) J/AJ/132/1275 : CIRS (Cluster Infall Regions in the SDSS). I (Rines+, 2006) J/A+A/470/39 : Substructures in WINGS clusters (Ramella+, 2007) J/MNRAS/390/289 : Radio observations of A3158 (Johnston-Hollitt+, 2008) J/A+A/540/A43 : New redshifts for Abell 1758N galaxies (Boschin+, 2012) J/A+A/540/A123 : Galaxy clusters from SDSS DR8 (Einasto+, 2012) J/MNRAS/436/275 : 2092 rich galaxy clusters relaxation parameter (Wen+, 2013) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 16 A16 --- Cluster Cluster name 18- 23 F6.2 10+14Msun Mass1 Mass of the first substructure 25- 29 F5.1 10+14Msun e_Mass1 Error on Mass1 31- 37 F7.3 deg RAdeg Rigth Ascension of first substructure (J2000) 39- 43 F5.3 deg e_RAdeg Error on RAdeg 45- 51 F7.3 deg DEdeg Declination of the first substructure (J2000) 53- 57 F5.3 deg e_DEdeg Error on DEdeg 59- 64 F6.4 --- z1 Redsfhit of the first substructure 66- 71 F6.4 --- e_z1 Error on z1 73- 78 F6.2 10+14Msun Mass2 Mass of the second substructure 80- 84 F5.2 10+14Msun e_Mass2 Error on Mass2 86- 92 F7.3 deg RA2deg Rigth Ascension of second substructure (J2000) 94- 98 F5.3 deg e_RA2deg Error on RA2deg 100-106 F7.3 deg DE2deg Declination of second substructure (J2000) 108-113 F6.4 deg e_DE2deg Error on RE2deg 115-121 F7.5 --- z2 Redsfhit of the second substructure 123-128 F6.4 --- e_z2 Error on z2 -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 26-May-2017