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J/ApJ/837/88 SPT-GMOS spectroscopy of gal. in massive clusters (Bayliss+, 2017)

Velocity segregation and systematic biases in velocity dispersion estimates with the SPT-GMOS spectroscopic survey. Bayliss M.B., Zengo K., Ruel J., Benson B.A., Bleem L.E., Bocquet S., Bulbul E., Brodwin M., Capasso R., Chiu I.-N., McDonald M., Rapetti D., Saro A., Stalder B., Stark A.A., Strazzullo V., Stubbs C.W., Zenteno A. <Astrophys. J., 837, 88-88 (2017)> =2017ApJ...837...88B (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Spectroscopy ; Redshifts ; Equivalent widths ; Velocity dispersion Keywords: cosmology: observations; galaxies: clusters: general; galaxies: distances and redshifts; galaxies: evolution; galaxies: kinematics and dynamics Abstract: The velocity distribution of galaxies in clusters is not universal; rather, galaxies are segregated according to their spectral type and relative luminosity. We examine the velocity distributions of different populations of galaxies within 89 Sunyaev Zel'dovich (SZ) selected galaxy clusters spanning 0.28<z<1.08. Our sample is primarily draw from the SPT-GMOS spectroscopic survey, supplemented by additional published spectroscopy, resulting in a final spectroscopic sample of 4148 galaxy spectra -- 2868 cluster members. The velocity dispersion of star-forming cluster galaxies is 17±4% greater than that of passive cluster galaxies, and the velocity dispersion of bright (m<m*-0.5) cluster galaxies is 11±4% lower than the velocity dispersion of our total member population. We find good agreement with simulations regarding the shape of the relationship between the measured velocity dispersion and the fraction of passive versus star-forming galaxies used to measure it, but we find a small offset between this relationship as measured in data and simulations, which suggests that our dispersions are systematically low by as much as 3% relative to simulations. We argue that this offset could be interpreted as a measurement of the effective velocity bias that describes the ratio of our observed velocity dispersions and the intrinsic velocity dispersion of dark matter particles in a published simulation result. Measuring velocity bias in this way suggests that large spectroscopic surveys can improve dispersion-based mass-observable scaling relations for cosmology even in the face of velocity biases, by quantifying and ultimately calibrating them out. Description: The majority of the data set used in this analysis comes from the SPT-GMOS spectroscopic survey (Bayliss+ 2016, J/ApJS/227/3), which consists of spectroscopic follow-up of 62 galaxy clusters from the SPT-SZ survey. The full SPT-GMOS sample includes 2243 galaxy spectra, 1579 of which are cluster member galaxies. In addition to previously published galaxy spectroscopy, we also present the first publication of new spectroscopy in the fields of three SPT galaxy clusters. We observed SPT-CLJ0000-5748, SPT-CLJ0516-5430, and SPT-CLJ2337-5942 with the Inamori Magellan Areal Camera and Spectrograph (IMACS) mounted on the Magellan-I (Baade) telescope at Las Campanas Observatory on the nights of 14-15 September 2012. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 125 1905 Catalog data for individual galaxies table2.dat 62 89 SZ-selected spectroscopic cluster sample
See also: J/ApJS/227/3 : Full spectroscopic data release of SPT-GMOS (Bayliss+, 2016) J/A+A/579/A4 : MCS J1206.2-0847 galaxies spectral classif. (Girardi+, 2015) J/ApJS/216/27 : Galaxy clusters discovered in the SPT-SZ survey (Bleem+, 2015) J/ApJ/792/45 : SPT-SZ survey galaxy clusters optical spectrosc. (Ruel+, 2014) J/ApJ/772/25 : Massive SZE clusters observations with ACT (Sifon+, 2013) J/ApJ/767/15 : Hectospec Cluster Survey (HeCS) (Rines+, 2013) J/ApJ/763/127 : Galaxy clusters discovered in the SPT survey (Reichardt+, 2013) J/ApJ/761/22 : NIR galaxy cluster candidates in the SPT survey (Song+, 2012) J/ApJS/193/8 : Spectroscopy of 26 lensing cluster cores (Bayliss+, 2011) J/ApJ/728/27 : Chandra and AAOmega observations of Abell 2744 (Owers+, 2011) J/A+A/421/59 : Equivalent widths of VMF73 and VMF74 galaxies (Gerken+, 2004) J/AJ/126/2152 : Cluster And Infall Region Nearby Survey. I (Rines+, 2003) J/ApJS/122/51 : Spectroscopic data of 10 rich galaxy clusters (Dressler+ 1999) J/ApJ/471/694 : Abell 2390 Gunn photometry & equivalent widths (Abraham+ 1996) J/A+A/310/8 : The ESO Nearby Abell Cluster Survey I. (Katgert+, 1996) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 16 A16 --- Cl Cluster name, SPT/ACT-CLJHHMM+DDMM (G1) 18- 36 A19 --- Gal Galaxy name, ( 38- 48 F11.7 deg RAdeg Galaxy Right Ascension in decimal degrees (J2000) 50- 60 F11.7 deg DEdeg Galaxy Declination in decimal degrees (J2000) 62- 70 F9.6 --- zsp [/4.3] Measured galaxy spectroscopic redshift 72- 79 F8.6 --- e_zsp [0/0.003] Uncertainty in zsp 81- 87 F7.2 0.1nm EWO2 [-326/66]?=999.99 Equivalent width of [OII]3727 line, in Angstroms units 89- 95 F7.2 0.1nm e_EWO2 [0/449]?=-999.99 Uncertainty in EWO2 97-103 F7.2 0.1nm EWHd [-117/133]?=999.99 Equivalent width of Hδ line, in Angstroms units 105-111 F7.2 0.1nm e_EWHd [0/203]?=-999.99 Uncertainty in EWHd 113-118 F6.2 mag rmag [16.9/25.3]?=-99.99 r band AB magnitude in SDSS system 120-125 F6.2 mag imag [16.4/24]?=-99.99 i band AB magnitude in SDSS system
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 16 A16 --- Cl Cluster name, SPT/ACT-CLJHHMM+DDMM (G1) 18 A1 --- f_Cl [b] b: discovered independently by ACT, Hasselfield+ (2013ApJS..209...17H) 20- 22 I3 --- Nsp [11/405] Total number of galaxy spectra with redshift measurements 24- 26 I3 --- Nmm [4/169] Number of cluster member galaxies 28- 30 I3 --- Npps [4/152] Number of passive and post-starburst members 32- 33 I2 --- Nsf [0/39] Number of star-forming members 35- 40 F6.4 --- z [0.27/1.08] Median cluster redshift 42- 47 F6.4 --- e_z [0.0003/0.005] Uncertainty in z 49- 52 I4 --- sigma [591/1916] Velocity dispersion estimate 54- 56 I3 --- e_sigma [56/953] Uncertainty in sigma 58- 62 A5 --- Ref Reference(s) for the published galaxy spectroscopy used (1)
Note (1): Reference(s) for the published galaxy spectroscopy used as follows: 1 = Bayliss et al. (2016, J/ApJS/227/3); 2 = Ruel et al. (2014, J/ApJ/792/45); 3 = Sifon et al. (2013, J/ApJ/772/25); 4 = this work.
Global notes: Note (G1): Sunyaev Zel'dovich-selected galaxy clusters from -- SPT = South Pole Telescope (SPT), Staniszewski+ (2009ApJ...701...32S); Vanderlinde+ (2010ApJ...722.1180V); Carlstrom+ (2011PASP..123..568C); Williamson+ (2011ApJ...738..139W); Reichardt+ (2013, J/ApJ/763/127); Bleem+ (2015, J/ApJS/216/27); ACT = Atacama Cosmology Telescope (ACT), Marriage+ (2011ApJ...737...61M); Hasselfield+ (2013ApJS..209...17H).
History: From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Oct-2017
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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