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J/A+A/435/781     Redshifts of galaxies in 21 EIS cluster fields  (Olsen+, 2005)

Multi-object spectroscopy of low redshift EIS clusters. III. Properties of optically selected clusters. Olsen L.F., Benoist C., da Costa L., Hansen L., Joergensen H.E. <Astron. Astrophys. 435, 781 (2005)> =2005A&A...435..781O
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Redshifts ; Velocity dispersion Keywords: galaxies: clusters: general - cosmology: observations - galaxies: distances and redshifts - galaxies: photometry Abstract: We have carried out an investigation of the properties of low redshift EIS clusters using both spectroscopy and imaging data. We present new redshifts for 738 galaxies in 21 ESO Imaging Survey (EIS) Cluster fields. We use the "gap"-technique to search for significant overdensities in redshift space and to identify groups/clusters of galaxies corresponding to the original EIS matched filter cluster candidates. In this way we spectroscopically confirm 20 of the 21 cluster candidates with a matched-filter estimated redshift zMF=0.2. We have now obtained spectroscopic redshifts for 34 EIS cluster candidates with zMF=0.2 (see also Hansen et al., 2002, Cat. J/A+A/388/1; Olsen et al., 2003, Cat. J/A+A/409/439. Of those we spectroscopically confirm 32 with redshifts ranging from z=0.064 to 0.283. We find that: 1) the velocity dispersions of the systems range from sigmav≤130km/s to sigmav=1200km/s, typical of galaxy groups to rich clusters; 2) richnesses corresponding to Abell classes R≤1; and 3) concentration indices ranging from C=0.2 to C=1.2. From the analysis of the colours of the galaxy populations we find that 53% of the spectroscopically confirmed systems have a "significant" red sequence. These systems are on average richer and have higher velocity dispersions. We find that the colour of the red sequence galaxies matches passive stellar evolution predictions. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 49 738 List of galaxy redshifts table5.dat 94 32 Properties of the confirmed EIS clusters and groups
See also: J/A+A/388/1 : Redshifts of five EIS clusters (Hansen+, 2002) J/A+A/409/439 : Redshifts of 11 EIS clusters (Olsen+, 2003) Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Sequential identification number for this table 6- 7 I2 h RAh Right ascension J2000 9- 10 I2 min RAm Right ascension J2000 12- 17 F6.3 s RAs Right ascension J2000 19 A1 --- DE- Declination sign J2000 20- 21 I2 deg DEd Declination J2000 23- 24 I2 arcmin DEm Declination J2000 26- 30 F5.2 arcsec DEs Declination J2000 35- 39 F5.2 mag Imag EIS I magnitude 43- 48 F6.4 --- z Measured redshift 49 A1 --- Notes [e:] e=emission line(s) (1)
Note (1): The note is: e = we identified emission line(s); : = an uncertain measurement, where no features could be identified.
Byte-by-byte Description of file: table5.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Sequential identification number for this table 5- 7 A3 --- --- [EIS] 8- 18 A11 --- Name EIS cluster name (JHHMM+DDMM) 21- 22 I2 --- Memb Number of member galaxies 24- 28 F5.3 --- z Mean redshift 30- 33 I4 km/s sigma Velocity dispersion 36- 38 I3 km/s E_sigma Upper error of sigma 41- 43 I3 km/s e_sigma Lower error of sigma 46- 49 F4.1 --- Rich Lambda-richness 52- 55 F4.2 --- CI Concentration index 58- 63 F6.3 mag V-Ip ?=-9.999 V-I from photometric analysis 64 A1 --- n_V-Ip [ab] Note when no data (1) 67- 70 F4.1 % sgp ?=-9.9 Significance of detected photometric sequence 71 A1 --- n_sgp [ab] Note when no data (1) 74- 79 F6.3 mag V-Is ?=-9.999 V-I from spectroscopic analysis 80 A1 --- n_V-Is [ab] Note when no data (1) 82- 85 F4.1 % sgs ?=-9.9 Significance of spectroscopic sequence 86 A1 --- n_sgs [ab] Note when no data (1) 88- 93 F6.3 mag Scatter ?=-9.999 Scatter of spectroscopic sequence 94 A1 --- n_Scatter [ab] Note when no data (1)
Note (1): Note when no photometric data as follows: a = no sequence was found b = V-I is not available
Acknowledgements: Lisbeth Fogh Olsen, olsen(at)
(End) Lisbeth Fogh Olsen [Obs. Nice], Patricia Vannier [CDS] 22-Feb-2005
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

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