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Title: SPT-GMOS: A Gemini/GMOS-South Spectroscopic survey of galaxy clusters in the SPT-SZ survey

Here, we present the results of SPT-GMOS, a spectroscopic survey with the Gemini Multi-Object Spectrograph (GMOS) on Gemini South. The targets of SPT-GMOS are galaxy clusters identified in the SPT-SZ survey, a millimeter-wave survey of 2500 deg 2 of the southern sky using the South Pole Telescope (SPT). Multi-object spectroscopic observations of 62 SPT-selected galaxy clusters were performed between 2011 January and 2015 December, yielding spectra with radial velocity measurements for 2595 sources. We identify 2243 of these sources as galaxies, and 352 as stars. Of the galaxies, we identify 1579 as members of SPT-SZ galaxy clusters. The primary goal of these observations was to obtain spectra of cluster member galaxies to estimate cluster redshifts and velocity dispersions. We describe the full spectroscopic data set and resulting data products, including galaxy redshifts, cluster redshifts, and velocity dispersions, and measurements of several well-known spectral indices for each galaxy: the equivalent width, W, of [O II] λλ3727, 3729 and H-δ, and the 4000 Å break strength, D4000. We use the spectral indices to classify galaxies by spectral type (i.e., passive, post-starburst, star-forming), and we match the spectra against photometric catalogs to characterize spectroscopically observed cluster members as a function of brightness (relativemore » to m*). Lastly, we report several new measurements of redshifts for ten bright, strongly lensed background galaxies in the cores of eight galaxy clusters. Combining the SPT-GMOS data set with previous spectroscopic follow-up of SPT-SZ galaxy clusters results in spectroscopic measurements for >100 clusters, or ~20% of the full SPT-SZ sample.« less
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Publication Date:
Report Number(s):
arXiv:1609.05211; FERMILAB-PUB-16-651-AE
Journal ID: ISSN 1538-4365; 129382; TRN: US1701296
Grant/Contract Number:
AC02-06CH11357; AC02-07CH11359; AC02-76SF00515
Accepted Manuscript
Journal Name:
The Astrophysical Journal. Supplement Series (Online)
Additional Journal Information:
Journal Name: The Astrophysical Journal. Supplement Series (Online); Journal Volume: 227; Journal Issue: 1; Journal ID: ISSN 1538-4365
American Astronomical Society/IOP
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
University of Chicago - Kavli Institute for Cosmological Physics; Gordon and Betty Moore Foundation; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; Catalogs; catalogs; galaxies: clusters: general; galaxies: distances and redshifts; techniques: spectroscopic
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1346382; OSTI ID: 1348408