J/AJ/132/1275 CIRS (Cluster Infall Regions in the SDSS). I. (Rines+, 2006)
CIRS: cluster infall regions in the Sloan Digital Sky Survey.
I. Infall patterns and mass profiles.
Rines K., Diaferio A.
<Astron. J., 132, 1275-1297 (2006)>
=2006AJ....132.1275R 2006AJ....132.1275R (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Morphology ; Redshifts ; Velocity dispersion
Keywords: cosmology: observations - galaxies: clusters: general -
galaxies: kinematics and dynamics
Abstract:
We use the Fourth Data Release of the Sloan Digital Sky Survey (SDSS)
to test the ubiquity of infall patterns around galaxy clusters and
measure cluster mass profiles to large radii. The Cluster and Infall
Region Nearby Survey (CAIRNS) found infall patterns in nine clusters,
but the cluster sample was incomplete. Here we match X-ray cluster
catalogs with SDSS, search for infall patterns, and compute mass
profiles for a complete sample of X-ray-selected clusters. Very clean
infall patterns are apparent in most of the clusters, with the
fraction decreasing with increasing redshift due to shallower
sampling. All 72 clusters in a well-defined sample limited by redshift
(ensuring good sampling) and X-ray flux (excluding superpositions)
show infall patterns sufficient to apply the caustic technique. This
sample is by far the largest sample of cluster mass profiles extending
to large radii to date. Similar to CAIRNS, cluster infall patterns are
better defined in observations than in simulations. Further work is
needed to determine the source of this difference. We use the infall
patterns to compute mass profiles for 72 clusters and compare them to
model profiles. Cluster scaling relations using caustic masses agree
well with those using X-ray or virial mass estimates, confirming the
reliability of the caustic technique. We confirm the conclusion of
CAIRNS that cluster infall regions are well fitted by
Navarro-Frenk-White (NFW) and Hernquist profiles and poorly fitted by
singular isothermal spheres. This much larger sample enables new
comparisons of cluster properties with those in simulations. The
shapes (specifically NFW concentrations) of the mass profiles agree
well with the predictions of simulations. The mass in the infall
region is typically comparable to or larger than that in the virial
region. Specifically, the mass inside the turnaround radius is on
average 2.19±0.18 times that within the virial radius. This ratio
agrees well with recent predictions from simulations of the final
masses of dark matter halos.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 80 74 CIRS Basic Properties
table3.dat 46 74 CIRS Hierarchical Centers and Offsets
table4.dat 62 74 CIRS Characteristic Radii and Masses
table5.dat 45 72 CIRS Mass Profile Fit Parameters
table6.dat 50 74 CIRS Virial and Projected Masses
--------------------------------------------------------------------------------
See also:
J/MNRAS/301/881 : The ROSAT brightest cluster sample - I. (Ebeling+, 1998)
J/A+A/425/367 : REFLEX Galaxy Cluster Survey catalogue (Boehringer+, 2004)
J/MNRAS/318/333 : Extended ROSAT Bright Cluster Sample (Ebeling+ 2000)
J/ApJS/129/435 : NORAS galaxy cluster survey. I. (Bohringer+, 2000)
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Cluster name
17- 25 F9.5 deg RAdeg Right Ascension in decimal degrees (J2000)
27- 35 F9.5 deg DEdeg Declination in decimal degrees (J2000)
37- 42 F6.4 --- z Heliocentric redshift
44- 50 A7 10+36W LX X-ray luminosity in units of 1043erg/s (1)
52- 57 A6 --- Cat X-ray cluster catalog (2)
59- 62 F4.2 keV TX X-ray temperature
64- 66 I3 km/s sig Projected velocity dispersion
68- 70 I3 km/s E_sig Upper limit uncertainty in sig
72- 73 I2 km/s e_sig Lower limit uncertainty in sig
75 I1 --- Cl [0/2] Contrast of caustics (3)
77- 80 F4.1 --- Rc Projected radius of nearest edge of
SDSS DR4 spectra (4)
--------------------------------------------------------------------------------
Note (1): X-ray luminosity assuming all X-ray flux due to this component.
Note (2): X-ray cluster catalog as follows:
REF = REFLEX (Bohringer et al., 2004, Cat. J/A+A/425/367)
BCS = BCS (Ebeling et al., 1998, Cat. J/MNRAS/301/881)
eBCS = eBCS (Ebeling et al., 2000, Cat. J/MNRAS/318/333)
NOR914 = NORAS main catalog (Bohringer et al., 2000,
Cat. J/ApJS/129/435)
NOR = NORAS supplemental 9h-14h catalog (Bohringer et al., 2000,
Cat. J/ApJS/129/435).
Note (3): Visual classification of contrast of infall pattern as follows:
0 = none
1 = intermediate
2 = clean
See text (S 3.1) for details.
Note (4): Projected radius of the nearest edge of the spectroscopic survey
of SDSS DR4. For several clusters, the caustic pattern disappears
beyond Rc because of this edge effect.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Cluster name
17- 25 F9.5 deg RAdeg Hierarchical center Right Ascension in
decimal degrees (J2000)
27- 35 F9.5 deg DEdeg Hierarchical center Declination in decimal
degrees (J2000)
37- 41 I5 km/s Delcz Hierarchial and X-ray redshift center difference
43- 46 I4 kpc DelR Hierarchial and X-ray position difference,
in h-1kpc units
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Cluster name
17- 20 F4.2 Mpc r500 Radius at 500 times critical density,
in h-1Mpc units
22- 25 F4.2 Mpc r200 Radius at 200 times critical density,
in h-1Mpc units
27- 30 F4.2 Mpc rt Turnaround radius, in h-1Mpc units
32- 36 F5.2 Mpc rmax Maximum caustic extent, in h-1Mpc units
38- 41 F4.2 10+14solMass M200 Mass within the r200 radius
43- 46 F4.2 10+14solMass e_M200 Uncertainty in M200
48- 52 F5.2 10+14solMass Mt Mass within the rt radius
54- 57 F4.2 10+14solMass e_Mt Uncertainty in Mt
59- 62 F4.2 --- Ratio Ratio of the mass within rmax and r200
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Cluster name
17- 21 F5.3 Mpc aNFW The NFW scale radius, in h-1Mpc units
23- 26 F4.2 --- r200 Radius at 200 times critical density,
in h-1Mpc units
28- 32 F5.2 --- cNFW The NFW concentration; r200/aNFW
34- 37 F4.2 10+14solMass M200 Mass within the r200 radius
39 A1 --- Pro [HNS] Best-fit profile (1)
41- 45 F5.2 --- c101 Concentration, r101/aNFW
--------------------------------------------------------------------------------
Note (1): Best-fit profile as follows:
H = Hernquist
N = NFW
S = SIS
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Cluster name
17- 20 F4.2 Mpc r200 Radius at 200 times critical density,
in h-1Mpc units
22- 25 F4.2 10+14solMass M200 Mass within the r200 radius
27- 30 F4.2 10+14solMass e_M200 Uncertainty in M200
32- 35 F4.2 10+14solMass MProj Projected mass
37- 40 F4.2 10+14solMass e_MProj Uncertainty in MProj
42- 45 F4.2 10+14solMass MVir Virial mass
47- 50 F4.2 10+14solMass e_MVir Uncertainty in MVir
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 25-Apr-2008