skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups

Abstract

We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic data to identify groups and clusters of galaxies in redshift space. The data set contains 8370 galaxies with confirmed redshifts in the range 0.7 {<=} z {<=} 1.4, over one square degree on the sky. Groups are identified using an algorithm (the Voronoi-Delaunay Method) that has been shown to accurately reproduce the statistics of groups in simulated DEEP2-like samples. We optimize this algorithm for the DEEP2 survey by applying it to realistic mock galaxy catalogs and assessing the results using a stringent set of criteria for measuring group-finding success, which we develop and describe in detail here. We find in particular that the group-finder can successfully identify {approx}78% of real groups and that {approx}79% of the galaxies that are true members of groups can be identified as such. Conversely, we estimate that {approx}55% of the groups we find can be definitively identified with real groups and that {approx}46% of the galaxies we place into groups are interloper field galaxies. Most importantly, we find that it is possible to measure the distribution of groups in redshift and velocity dispersion, n({sigma}, z), to an accuracy limited by cosmic variance, formore » dispersions greater than 350 km s{sup -1}. We anticipate that such measurements will allow strong constraints to be placed on the equation of state of the dark energy in the future. Finally, we present the first DEEP2 group catalog, which assigns 32% of the galaxies to 899 distinct groups with two or more members, 153 of which have velocity dispersions above 350 km s{sup -1}. We provide locations, redshifts and properties for this high-dispersion subsample. This catalog represents the largest sample to date of spectroscopically detected groups at z {approx} 1.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; « less
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1035122
Report Number(s):
SLAC-PUB-14492
Journal ID: ISSN 0004--637X; TRN: US201204%%347
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Journal Article
Journal Name:
Submitted to Astrophysical Journal
Additional Journal Information:
Journal Volume: 751; Journal Issue: 1; Journal ID: ISSN 0004--637X
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCURACY; ALGORITHMS; DISTRIBUTION; GALAXIES; GALAXY CLUSTERS; RED SHIFT; SKY; STATISTICS; VELOCITY; Astrophysics,GRQC, ASTRO

Citation Formats

Gerke, Brian F., /UC, Berkeley, Newman, Jeffrey A., /LBNL, NSD, Davis, Marc, /UC, Berkeley /UC, Berkeley, Astron.Dept., Marinoni, Christian, /Brera Observ., Yan, Renbin, Coil, Alison L., Conroy, Charlie, Cooper, Michael C., /UC, Berkeley, Astron.Dept., Faber, S.M., /Lick Observ., Finkbeiner, Douglas P., /Princeton U. Observ., Guhathakurta, Puragra, /Lick Observ., Kaiser, Nick, /Hawaii U., Koo, David C., Phillips, Andrew C., /Lick Observ., Weiner, Benjamin J., and /Maryland U. The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups. United States: N. p., 2012. Web. doi:10.1088/0004-637X/751/1/50.
Gerke, Brian F., /UC, Berkeley, Newman, Jeffrey A., /LBNL, NSD, Davis, Marc, /UC, Berkeley /UC, Berkeley, Astron.Dept., Marinoni, Christian, /Brera Observ., Yan, Renbin, Coil, Alison L., Conroy, Charlie, Cooper, Michael C., /UC, Berkeley, Astron.Dept., Faber, S.M., /Lick Observ., Finkbeiner, Douglas P., /Princeton U. Observ., Guhathakurta, Puragra, /Lick Observ., Kaiser, Nick, /Hawaii U., Koo, David C., Phillips, Andrew C., /Lick Observ., Weiner, Benjamin J., & /Maryland U. The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups. United States. doi:10.1088/0004-637X/751/1/50.
Gerke, Brian F., /UC, Berkeley, Newman, Jeffrey A., /LBNL, NSD, Davis, Marc, /UC, Berkeley /UC, Berkeley, Astron.Dept., Marinoni, Christian, /Brera Observ., Yan, Renbin, Coil, Alison L., Conroy, Charlie, Cooper, Michael C., /UC, Berkeley, Astron.Dept., Faber, S.M., /Lick Observ., Finkbeiner, Douglas P., /Princeton U. Observ., Guhathakurta, Puragra, /Lick Observ., Kaiser, Nick, /Hawaii U., Koo, David C., Phillips, Andrew C., /Lick Observ., Weiner, Benjamin J., and /Maryland U. Tue . "The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups". United States. doi:10.1088/0004-637X/751/1/50. https://www.osti.gov/servlets/purl/1035122.
@article{osti_1035122,
title = {The DEEP2 Galaxy Redshift Survey: The Voronoi-Delaunay Method Catalog of Galaxy Groups},
author = {Gerke, Brian F. and /UC, Berkeley and Newman, Jeffrey A. and /LBNL, NSD and Davis, Marc and /UC, Berkeley /UC, Berkeley, Astron.Dept. and Marinoni, Christian and /Brera Observ. and Yan, Renbin and Coil, Alison L. and Conroy, Charlie and Cooper, Michael C. and /UC, Berkeley, Astron.Dept. and Faber, S.M. and /Lick Observ. and Finkbeiner, Douglas P. and /Princeton U. Observ. and Guhathakurta, Puragra and /Lick Observ. and Kaiser, Nick and /Hawaii U. and Koo, David C. and Phillips, Andrew C. and /Lick Observ. and Weiner, Benjamin J. and /Maryland U.},
abstractNote = {We use the first 25% of the DEEP2 Galaxy Redshift Survey spectroscopic data to identify groups and clusters of galaxies in redshift space. The data set contains 8370 galaxies with confirmed redshifts in the range 0.7 {<=} z {<=} 1.4, over one square degree on the sky. Groups are identified using an algorithm (the Voronoi-Delaunay Method) that has been shown to accurately reproduce the statistics of groups in simulated DEEP2-like samples. We optimize this algorithm for the DEEP2 survey by applying it to realistic mock galaxy catalogs and assessing the results using a stringent set of criteria for measuring group-finding success, which we develop and describe in detail here. We find in particular that the group-finder can successfully identify {approx}78% of real groups and that {approx}79% of the galaxies that are true members of groups can be identified as such. Conversely, we estimate that {approx}55% of the groups we find can be definitively identified with real groups and that {approx}46% of the galaxies we place into groups are interloper field galaxies. Most importantly, we find that it is possible to measure the distribution of groups in redshift and velocity dispersion, n({sigma}, z), to an accuracy limited by cosmic variance, for dispersions greater than 350 km s{sup -1}. We anticipate that such measurements will allow strong constraints to be placed on the equation of state of the dark energy in the future. Finally, we present the first DEEP2 group catalog, which assigns 32% of the galaxies to 899 distinct groups with two or more members, 153 of which have velocity dispersions above 350 km s{sup -1}. We provide locations, redshifts and properties for this high-dispersion subsample. This catalog represents the largest sample to date of spectroscopically detected groups at z {approx} 1.},
doi = {10.1088/0004-637X/751/1/50},
journal = {Submitted to Astrophysical Journal},
issn = {0004--637X},
number = 1,
volume = 751,
place = {United States},
year = {2012},
month = {2}
}