J/A+A/459/L1 Supercluster sample from SDSS DR4 (Einasto+, 2006)
Luminous superclusters: remnants from inflation?
Einasto J., Einasto M., Saar E., Tago E., Liivamaegi L.J., Joeveer M.,
Suhhonenko I., Huetsi G., Jaaniste J., Heinaemaeki P., Mueller V.,
Knebe A., Tucker D. (5)
<Astron. Astrophys. 459, L1 (2006)>
=2006A&A...459L...1E 2006A&A...459L...1E
ADC_Keywords: Clusters, galaxy ; Morphology
Keywords: cosmology: large-scale structure of Universe -
galaxies: clusters: general
Abstract:
We compile a supercluster sample using the Sloan Digital Sky Survey
Data Release 4, and reanalyse supercluster samples found for the 2dF
Galaxy Redshift Survey and for simulated galaxies of the Millennium
Run. We find for all supercluster samples Density Field (DF) clusters,
which represent high-density peaks of the class of Abell clusters, and
use median luminosities of richness class 1 DF-clusters to calculate
relative luminosity functions. We show that the fraction of very
luminous superclusters in real samples is about five times greater
than in simulated samples. Superclusters are generated by large-scale
density perturbations that evolve very slowly. The absence of very
luminous superclusters in simulations can be explained either by
incorrect treatment of large-scale perturbations, or by some yet
unknown processes in the very early Universe.
Description:
Tables contain data on superclusters, selected from SDSS DR4
high-declination region data. Method to select superclusters is
described in the paper and in a forthcomming paper (Einasto et al.,
"Superclusters of galaxies from the 2dF redshift survey. I. The
catalogue", in press) Table A contains the main catalogue with
superclusters located at distances up to 520Mpc/h, Table B contains
supplementary superclusters at distances over 520Mpc/h.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
scldr4a.dat 138 687 Supercluster sample using SDSS DR4 (d<520Mpc/h)
scldr4b.dat 138 224 Supercluster sample using SDSS DR4 (d>520Mpc/h)
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See also:
http://www.sdss.org/dr4 : SDSS DR4 Home Page
http://www.mso.anu.edu.au/2dFGRS : The 2dF Galaxy Redshift Survey Home Page
Byte-by-byte Description of file: scldr4a.dat scldr4b.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/911] Identification number
5- 13 F9.5 deg RAdeg Right Ascension (for the epoch J2000)
15- 23 F9.5 deg DEdeg Declination (for the epoch J2000)
25- 32 F8.5 deg Eta SDSS survey η coordinate (epoch J2000)
34- 42 F9.5 deg Lambda SDSS survey λ coordinate (epoch J2000)
44- 49 F6.2 Mpc Dist Distance
51- 55 F5.2 Mpc Dmin Minimal size of the supercluster (1)
57- 62 F6.2 Mpc Dmax Maximal diameter of the supercluster (2)
64- 68 F5.2 Mpc Deff Effective diameter De (3)
70- 73 F4.2 --- eps0 Ratio of the mean to effective diameter (4)
75- 79 F5.2 --- Offset Center offset parameter (5)
81- 85 F5.2 ---- Speak Peak density (in units of the mean density)
87- 91 F5.2 --- Smean Mean density (in units of the mean density)
93- 96 I4 --- Ngal Number of galaxies in the supercluster
98-100 I3 --- Ngr Number of groups (including groups with only
one visible galaxy) in the supercluster
102-103 I2 --- Ncl Multiplicity of the supercluster
(the number of DF-clusters)
105-110 I6 --- ID Identification of the main cluster according to
the group catalogue by Tago et al.
(2006, A&A, in preparation) (6)
112-114 I3 --- Ngvis Number of visible galaxies in the main cluster
116-126 E11.6 solLum Lmain Luminosity of the main galaxy
128-138 E11.6 solLum Ltot Total estimated luminosity of the
supercluster (7)
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Note (1): Dmin=min(dx,dy,dz), where dx, dy, and dz are sizes of the
supercluster along coordinates x, y, z; the sizes are determined
from extreme coordinates of the density field above threshold
density along coordinate axes.
Note (2): Diagonal of the box containing the supercluster,
Dmax=(dx2+dy2+dz2)1/2.
Note (3): The diameter of the sphere, equal to the volume of the supercluster.
Note (4): epsilon0=Dm/De, here Dm=Dmax/31/3 is the mean diameter.
This parameter characterizes the compactness of the system.
Note (5): Deltao=((x0- xm)2+(y0-ym)2+(z0-zm)2)1/2;
here x0, y0, z0 are coordinates of the geometric center
of the supercluster, found on the basis of extreme values of
coordinates, and xm, ym, zm are coordinates of the dynamical
center (main cluster) of the supercluster. This parameter
characterises the asymmetry of the supercluster.
Note (6): Identification number of the main cluster (group number) for
galaxies in group, or identification number of the galaxy for
isolated galaxies (not in group) in "SDSS DR4 group catalogue".
Note (7): Ltot, in photometric system r, expressed in Solar units.
The total luminosity was found by summing all estimated total
luminosities of member groups of the supercluster.
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Acknowledgements:
Jaan Einasto, einasto(at)aai.ee
(End) Patricia Vannier [CDS] 04-Dec-2006