NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-18 T02:45:19 PDT
Help | Comment | NED Home

For refcode 1993MNRAS.265..553C:
Retrieve 42 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by Royal Astronomical Society. 1993MNRAS.265..553C Metallicity gradients in early-type galaxies C. M. Carollo, Danziger and L. Buson European Southern Observatory, Karl-Schwartschildstrasse 2, D-85748, Garching bei Munchen, Germany Osservatorio Astronomico di Padova, Vicolo dell `Osservatorio 5,1-35100 Padova, Italy Accepted 1993 May 22. Received 1993 May 21; In original form 1993 January 16 ABSTRACT Long-slit spectra in the range 4500-6500 A have been obtained for a sample of 42 galaxies. Rotation velocities and velocity dispersions, together with radial line strength gradients of Mg_2_, Mg_1_, H{beta}, NaD, TiO_1_, TiO_2_ and Fe_5270_, have been measured to, on average, half an effective radius. To a high level of significance, Mg_2_ gradients positively correlate with those of Mg_1_ and Na D, but no correlation is observed with the other indices. In addition, correlations of Mg_2_ gradients with various physical parameters are studied. For galaxies smaller than about 10^11^ M_sun_, the Mg_2_ gradient increases with increasing mass, but more massive objects show no correlation. In low- mass galaxies, the correlation of Mg_2_ gradients with mass suggests dissipative collapse as the mechanism acting during the initial star formation episode. Different formation mechanisms, such as, for example, a less dissipative collapse and/or merging of smaller systems, are discussed as a means of explaining the lack of correlation at higher masses. Even at low masses, the galactic mass seems not to influence either the position or the slope on the Fe_5270_-Mg_2_ plane, abundance ratios within galaxies depending on still-unidentified parameters. Key words: galaxies: abundances - galaxies: elliptical and lenticular, cD - galaxies: fundamental parameters.
Retrieve 42 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home