NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2018-12-11 T03:46:19 PST
Help | Comment | NED Home

For refcode 1999MNRAS.305..259W:
Retrieve 849 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by Royal Astronomical Society. 1999MNRAS.305..259W The peculiar motions of early-type galaxies in two distant regions - II. The spectroscopic data Gary Wegner, Matthew Colless, R. P. Saglia, Robert K. McMahan Jr, Roger L. Davies, David Burstein and Glenn Baggley Accepted 1998 November 26. Received 1998 September 23; in original form 1998 July 17 ABSTRACT We present the spectroscopic data for the galaxies studied in the EFAR project, which is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. We have obtained 1319 spectra of 714 early-type galaxies over 33 observing runs on 10 different telescopes. We describe the observations and data reductions used to measure redshifts, velocity dispersions and the Mgb and Mg2 Lick linestrength indices.Detailed simulations and intercomparison of the large number of repeat observations lead to reliable error estimates for all quantities. The measurements from different observing runs are calibrated to a common zero-point or scale before being combined, yielding a total of 706 redshifts, 676 velocity dispersions, 676 Mgb linestrengths and 582 Mg2 linestrengths. The median estimated errors in the combined measurements are {DELTA}cz=20 km s^-1^, {DELTA}{sigma/{sigma}= 9.1 per cent, {DELTA}Mgb/Mgb=7.2 per cent and {DELTA}Mg2=0.015 mag. Comparison of our measurements with published data sets shows no systematic errors in the redshifts or velocity dispersions, and only small zero-point corrections to bring our linestrengths on to the standard Lick system. We have assigned galaxies to physical clusters by examining the line-of-sight velocity distributions based on EFAR and ZCAT redshifts, together with the projected distributions on the sky. We derive mean redshifts and velocity dispersions for these clusters, which will be used in estimating distances and peculiar velocities and to test for trends in the galaxy population with cluster mass. The spectroscopic parameters presented here for 706 galaxies combine high-quality data, uniform reduction and measurement procedures, and detailed error analysis. They form the largest single set of velocity dispersions and linestrengths for early-type galaxies published to date. Keywords:surveys galaxies: clusters: general galaxies: distances and redshifts galaxies: elliptical and lenticular, cD large-scale structure of Universe
Retrieve 849 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home