J/MNRAS/461/248 44 SZ-selected galaxy clusters ACT observations (Sifon+, 2016)
The Atacama Cosmology Telescope: dynamical masses for 44 SZ-selected galaxy
clusters over 755 square degrees.
Sifon C., Battaglia N., Hasselfield M., Menanteau F., Barrientos L.F.,
Bond J.R., Crichton D., Devlin M.J., Dunner R., Hilton M., Hincks A.D.,
Hlozek R., Huffenberger K.M., Hughes J.P., Infante L., Kosowsky A.,
Marsden D., Marriage T.A., Moodley K., Niemack M.D., Page L.A.,
Spergel D.N., Staggs S.T., Trac H., Wollack E.J.
<Mon. Not. R. Astron. Soc., 461, 248-270 (2016)>
=2016MNRAS.461..248S 2016MNRAS.461..248S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Redshifts
Keywords: galaxies: clusters: general - Galaxies: distances and redshifts -
cosmology: observations - large-scale structure of Universe
Abstract:
We present galaxy velocity dispersions and dynamical mass estimates
for 44 galaxy clusters selected via the Sunyaev-Zel'dovich (SZ) effect
by the Atacama Cosmology Telescope. Dynamical masses for 18 clusters
are reported here for the first time. Using N-body simulations, we
model the different observing strategies used to measure the velocity
dispersions and account for systematic effects resulting from these
strategies. We find that the galaxy velocity distributions may be
treated as isotropic, and that an aperture correction of up to 7 per
cent in the velocity dispersion is required if the spectroscopic
galaxy sample is sufficiently concentrated towards the cluster centre.
Accounting for the radial profile of the velocity dispersion in
simulations enables consistent dynamical mass estimates regardless of
the observing strategy. Cluster masses M200 are in the range
(1-15)x1014M☉. Comparing with masses estimated from the SZ
distortion assuming a gas pressure profile derived from X-ray
observations gives a mean SZ-to-dynamical mass ratio of 1.10±0.13,
but there is an additional 0.14 systematic uncertainty due to the
unknown velocity bias; the statistical uncertainty is dominated by the
scatter in the mass-velocity dispersion scaling relation. This ratio
is consistent with previous determinations at these mass scales.
Description:
ACT is a 6-metre off-axis Gregorian telescope located at an altitude
of 5200um in the Atacama desert in Chile, designed to observe the CMB
at arcminute resolution.
Galaxy clusters were detected in the 148GHz band by matched-filtering
the maps with the pressure profile suggested by Arnaud et al.
(2010A&A...517A..92A 2010A&A...517A..92A), fit to X-ray selected local (z<0.2) clusters,
with varying cluster sizes,θ500, from 1.18 to 27-arcmin.
Because of the complete overlap of ACT equatorial observations with
Sloan Digital Sky Survey Data Release 8 (SDSS DR8; Aihara et al.,
2011ApJS..193...29A 2011ApJS..193...29A) imaging, all cluster candidates were assessed
with optical data (Menanteau et al., 2013ApJ...765...67M 2013ApJ...765...67M).
We observed 20 clusters from the equatorial sample with the Gemini
Multi-Object Spectrograph (GMOS) on the Gemini-South telescope, split
in semesters 2011B (ObsID:GS-2011B-C-1, PI:Barrientos/Menanteau) and
2012A (ObsID:GS-2012A-C-1, PI:Menanteau), prioritizing clusters in the
cosmological sample at 0.3<z<1.0. All observations followed our
setup for the southern sample (Sifon et al. 2013, Cat. J/ApJ/772/25).
We also observed seven clusters in S82 with the Robert Stobie
Spectrograph (RSS) on the Southern African Large Telescope (SALT),
using MOS. Details of these observations are given in Kirk et al.
(2015, Cat. J/MNRAS/449/4010).
In order to enlarge the sample of studied clusters and member
galaxies, we also compiled archival data for the equatorial sample.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tableb1.dat 65 9203 Full spectroscopic catalogue
--------------------------------------------------------------------------------
See also:
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
J/ApJS/122/51 : 10 rich galaxy clusters spectroscopic cat. (Dressler+ 1999)
J/ApJ/772/25 : Massive SZE clusters observations with ACT (Sifon+, 2013)
J/ApJ/767/15 : Hectospec Cluster Survey (HeCS) (Rines+, 2013)
J/MNRAS/449/4010 : SALT galaxy clusters detected by ACT (Kirk+, 2015)
Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- Name Catalogue designation (JHHMMSS.ss+DDMMSS.s)
20 A1 --- n_Name [*] * for BCG
22- 23 I2 h RAh Right ascension (J2000)
25- 26 I2 min RAm Right ascension (J2000)
28- 32 F5.2 s RAs Right ascension (J2000)
34 A1 --- DE- Declination sign (J2000)
35- 36 I2 deg DEd Declination (J2000)
38- 39 I2 arcmin DEm Declination (J2000)
41- 44 F4.1 arcsec DEs Declination (J2000)
46- 53 F8.5 --- z Redshift
55- 61 F7.5 --- e_z Nominal uncertainty on z
63 A1 --- Memb [0/1] Membership flag (1)
65 I1 --- r_z Spectroscopic source (2)
--------------------------------------------------------------------------------
Note (1): Membership flag as follows:
1 = member
0 = non-member
Note (2): References as follows:
1 = Gemini/GMOS (this work)
2 = Gemini/GMOS (Sifon et al., 2013, Cat. J/ApJ/772/25)
3 = VLT/FORS2 (Sifon et al., 2013, Cat. J/ApJ/772/25)
4 = SALT/RSS (Kirk et al., 2015, Cat. J/MNRAS/449/4010)
5 = SDSS DR12 (Alam et al., 2015ApJS..219...12A 2015ApJS..219...12A, Cat. V/147)
6 = HeCS (Rines et al., 2013, Cat. J/ApJ/767/15)
7 = Soucail et al. (1988A&AS...73..471S 1988A&AS...73..471S)
8 = Dressler et al. (1999, Cat. J/ApJS/122/51)
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Nov-2017