J/MNRAS/351/265 Cluster galaxy circular velocity function (Desai+, 2004)
The cluster galaxy circular velocity function.
Desai V., Dalcanton J.J., Mayer L., Reed D., Quinn T., Governato F.
<Mon. Not. R. Astron. Soc., 351, 265-278 (2004)>
=2004MNRAS.351..265D 2004MNRAS.351..265D
ADC_Keywords: Clusters, galaxy ; Redshifts ; Velocity dispersion
Keywords: methods: N-body simulations - galaxies: clusters: general -
galaxies: haloes - cosmology: observations - cosmology: theory -
dark matter
Abstract:
We present galaxy circular velocity functions (GCVFs) for 34
low-redshift (z≲0.15) clusters identified in the Sloan Digital Sky
Survey (SDSS, Cat. J/AJ/123/567), for 15 clusters drawn from dark
matter simulations of hierarchical structure growth in a {LAMBDA}CDM
cosmology, and for ∼22000 SDSS field galaxies. We find that the
simulations successfully reproduce the shape, amplitude and scatter in
the observed distribution of cluster galaxy circular velocities. The
power-law slope of the observed cluster GCVF is ~-2.4, independent of
cluster velocity dispersion. The average slope of the simulated GCVFs
is somewhat steeper, although formally consistent given the errors. We
find that the effects of baryons on galaxy rotation curves is to
flatten the simulated cluster GCVF into better agreement with
observations. The cumulative GCVFs of the simulated clusters are very
similar across a wide range of cluster masses, provided individual
subhalo circular velocities are scaled by the circular velocities of
the parent cluster. The scatter is consistent with that measured in
the cumulative, scaled observed cluster GCVF. Finally, the observed
field GCVF deviates significantly from a power law, being flatter than
the cluster GCVF at circular velocities less than 200km/s.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 80 34 Galaxy cluster sample
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See also:
J/AJ/123/567 : SDSS quasar catalog. I. Early Data Release (Schneider+, 2002)
J/AJ/126/2579 : SDSS quasar catalog. II. First data release (Schneider+, 2003)
J/AJ/125/1817 : SDSS Early-Type Galaxies Catalog (Bernardi+, 2003)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Rigth ascension (J2000)
4- 5 I2 min RAm Rigth ascension (J2000)
7- 12 F6.3 s RAs Rigth ascension (J2000)
14 A1 --- DE- Declination sign (J2000)
15- 16 I2 deg DEd Declination (J2000)
18- 19 I2 arcmin DEm Declination (J2000)
21- 25 F5.2 arcsec DEs Declination (J2000)
27- 31 F5.3 --- z Redshift
33- 35 I3 km/s sigmacl Line-of-sight cluster velocity dispersion
37- 39 I3 km/s e_sigmacl rms uncertainty on sigmacl
41- 44 F4.2 Mpc Rvir Virial radius of the cluster
46- 47 I2 km/s Vcompl Completeness limit of the cluster
galaxy circular velocity function (GCVF)
49- 53 F5.2 [---] log(N200) Normalization at Vc=200km/s (1)
55- 58 F4.2 [---] e_log(N200) rms uncertainty on log(N200)
60- 64 F5.2 --- beta Slope of the power law (1)
66- 69 F4.2 --- e_beta rms uncertainty on beta
71- 75 F5.2 [---] log(N200)f Value of log(N200) by fitting beta to its
average value -2.4
77- 80 F4.2 [---] e_log(N200)f rms uncertainty on log(N200)f
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Note (1): We fit a power law to our observed GCVFs as
log10[dN(Vc)/dVc]=log10(N200) + β*log10(Vc/200km/s)
where β is the slope of the power law and
N200 is the normalization at Vc=200km/s.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 19-Jul-2004