J/A+A/399/813 Multiple merging events in Abell 521 (Ferrari, 2003)
Multiple merging events in Abell 521
Ferrari C., Maurogordato S., Cappi A., Benoist C.
<Astron. Astrophys. 399, 813 (2003)>
=2003A&A...399..813F 2003A&A...399..813F
ADC_Keywords: Clusters, galaxy ; Galaxies, spectra; Redshifts
Keywords: galaxies: clusters: general ;
galaxies: clusters: individual: Abell 521 ;
galaxies: distances and redshifts ; cosmology: observations
Keywords:galaxies: clusters: general - galaxies: clusters: individual
(Abell 521) - galaxies: distances and redshifts -
cosmology: observations
Abstract:
We present a detailed spatial and dynamical analysis of the central
∼2.2Mpc(Ho=75km/s/Mpc) region of the galaxy cluster Abell 521
(z=0.247), based on 238 spectra (of which 191 new measurements)
obtained at the 3.6m Telescope of the European Southern Observatory
and at the Canada-France-Hawaii Telescope. From the analysis of the
125 galaxies that are confirmed members of the cluster, we derive a
location ("mean" velocity) of CBI=74019{+112}{-125}km/s and
detect a complex velocity distribution with high velocity scale
("dispersion", SBI=1325{+145}{-100}km/s), but clear departure
from a single Gaussian component. When excluding a possible background
group of four galaxies, the velocity dispersion remains still large
(∼1200 km/s).
Description:
Radial velocity measurements and spectral features of 191 objects in
the central region of the galaxy cluster Abell 521, observed through
a campaign of multi-object spectroscopy at the ESO 3.6m telescope
(3 nights in October 1999, and 2.5 nights in December 2000).
The spectral resolution is 1.85nm in October 1999 and 1.25nm in
December 2000 (FWHM)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table10.dat 64 191 Radial velocities and spectral lines for
191 galaxies in A521
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Id Identification number
5- 8 A4 --- Run Run of observations
10- 11 I2 h RAh Right ascension (J2000.0)
13- 14 I2 min RAm Right ascension (J2000.0)
16- 20 F5.2 s RAs Right ascension (J2000.0)
22 A1 --- DE- Declination sign (J2000.0)
23- 24 I2 deg DEd Declination (J2000.0)
26- 27 I2 arcmin DEm Declination (J2000.0)
29- 33 F5.2 arcsec DEs Declination (J2000.0)
35- 40 I6 km/s cz [-2,]?=-1 Radial velocity (2)
42- 44 I3 km/s e_cz [-2,]?=-1 Error on radial velocity (2)
46 I1 --- q_cz Quality flag for the redshift determination (1)
48- 64 A17 --- Em.Lines Emission lines present in the spectrum
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Note (1): We have classified the quality of the spectra in the following way:
1 = good determination (R≥3),
2 = uncertain determination,
3 = very poor determination,
4 = failed spectra
Note (2): The negative values mean:
-1 = the galaxy velocity could not be determined
-2 = object is a star
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Author's address:
Chiara Ferrari
(End) Chiara Ferrari [OCA, France] 26-Feb-2003