J/ApJS/148/243 Catalog of clusters of galaxies from SDSS (Bahcall+, 2003)
A merged catalog of clusters of galaxies from Early Sloan Digital Sky Survey Data. Bahcall N.A., McKay T.A., Annis J., Kim R.S.J., Dong F., Hansen S., Goto T., Gunn J.E., Miller C., Nichol R.C., Postman M., Schneider D., Schroeder J., Voges W., Brinkmann J., Fukugita M. <Astrophys. J. Suppl. Ser. 148, 243 (2003)> =2003ApJS..148..243B
ADC_Keywords: Clusters, galaxy ; Redshifts Keywords: catalogs - cosmology: observations - cosmology: theory - galaxies: clusters: general - large-scale structure of universe Abstract: We present a catalog of 799 clusters of galaxies in the redshift range zest=0.05-0.3 selected from ∼400deg2 of early Sloan Digital Sky Survey (SDSS) commissioning data along the celestial equator. The catalog is based on merging two independent selection methods - a color-magnitude red-sequence maxBCG technique (B), and a hybrid matched filter method (H). The BH catalog includes clusters with richness Λ≥40 (matched filter) and Ngal≥13 (maxBCG), corresponding to typical velocity dispersion of σv≳400km/s and mass (within 0.6h-1Mpc radius) ≳5x1013h-1M☉. This threshold is below Abell richness class 0 clusters. The average space density of these clusters is 2x10-5h3/Mpc3. All NORAS (J/ApJS/129/435) X-ray clusters and 53 of the 58 Abell clusters in the survey region are detected in the catalog; the five additional Abell clusters are detected below the BH catalog cuts. The cluster richness function is determined and found to exhibit a steeply decreasing cluster abundance with increasing richness. We derive observational scaling relations between cluster richness and observed cluster luminosity and cluster velocity dispersion; these scaling relations provide important physical calibrations for the clusters. The catalog can be used for studies of individual clusters, for comparisons with other sources such as X-ray clusters and active galactic nuclei, and, with proper correction for the relevant selection functions, also for statistical analyses of clusters. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file catalog.dat 92 799 *BH SDSS cluster catalog
Note on catalog.dat: General comments to catalog: (HMF = Hybrid Matched Filter detection method) 1: zest=0.05-0.3; 379°2 covering the area RA(2000)=355° to 56° and 145.3° to 236.0°, DE(2000)=-1.25° to 1.25°. 2: All HMF clusters with Λ≥40, maxBCG clusters with NGal≥13, and their matches are included (see #4 below). 3: Some detections are false-positives, i.e., non-real clusters (Section 5); all are included in order to avoid unquantitative visual selection. 4: Cluster matches are algorithmically defined as B and H clusters separated by ≤1h-1Mpc (projected) and Δzest≤0.08 (2.5-σ). All matching clusters with NGal≥6 and Λ≥20 are included. 5: The same cluster is sometimes listed as two separate H and B clusters (i.e., 'un-matched') if the separation is Δzest>0.08 or >1h-1Mpc (due to uncertainties in zest and the different definitions of cluster 'center'). (If one of the 'un-matched' clusters is below the catalog richness or redshift cuts, it will not be listed in the catalog.) 6: Occasionally, a single H or B cluster may be split by the detection algorithm into two separate clusters; this may represent sub-structure in larger systems. 7: HMF clusters are typically centered on a mean high overdensity region of galaxies; maxBCG clusters center on a galaxy with a color and magnitude estimated as likely to be a BCG. Some B clusters thus center on a bright galaxy or small group of red galaxies in the outskirts of clusters. (This can cause splitting of a cluster match into two or more separate listings; see #5). This may also represent sub-structure in or near clusters. 8: Some systems may represent parts of extended large-scale structure rather than condensed virialized clusters. 9: The catalog is not volume limited. Selection functions as a function of redshift and richness are provided in Section 5.
See also: J/ApJS/129/435 : NORAS galaxy cluster survey. I. (Bohringer+, 2000) Byte-by-byte Description of file: catalog.dat
Bytes Format Units Label Explanations
1- 3 I3 --- [BMA2003] The BH SDSS cluster number 5- 7 A3 --- Meth Method of detection (1) 10- 16 F7.3 deg RAHdeg ? HMF Right Ascension expressed in decimal degrees (J2000) 17- 23 F7.3 deg DEHdeg ? HMF Declination expressed in decimal degrees (J2000) 26- 29 F4.2 --- zHMF ? The HMF redshift estimate 32- 35 F4.1 --- Lambda ? The HMF cluster richness 38- 44 F7.3 deg RABdeg ? The maxBCG Right Ascension expressed in decimal degrees (J2000) 45- 51 F7.3 deg DEBdeg ? The maxBCG Declination expressed in decimal degrees (J2000) 54- 58 F5.3 --- zBCG ? The maxBCG redshift estimate 61- 62 I2 --- NGal ? The maxBCG richness estimate 65- 69 F5.3 --- zspec ? SDSS spectroscopic redshift 73- 92 A20 --- n_[BMA2003] Additional comments on [BMA2003]
Note (1): Method of detection: H = HMF (Hybrid Matched Filter); B = maxBCG (Brightest Cluster Galaxy); h or b = cluster match outside the catalog richness or redshift thresholds, i.e., Λ<40, NGal<13, z>0.3.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Bauer [CDS] 24-Oct-2003
|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|