TY - JOUR
T1 - On the origin of the color-magnitude relation in the Virgo Cluster
AU - Vazdekis, Alexandre
AU - Kuntschner, Harald
AU - Davies, Roger L.
AU - Arimoto, Nobuo
AU - Nakamura, Osamu
AU - Peletier, Reynier
N1 - Funding Information:
The authors thank J. Blakeslee, R. Bower, J. Gorgas, T. Ko-dama, J. Lucey, and the referee, J. J. González, for valuable discussions and suggestions. A. V. and H. K. acknowledge the support of the PPARC rolling grant “Extragalactic Astronomy and Cosmology in Durham 1998–2002.” This work was financially supported in part by a Grant-in-Aid for Scientific Research (1164032) by the Japanese Ministry of Education, Culture, Sports, and Science. R. L. D. acknowledges the support of a Leverhulme Trust Research Fellowship.
PY - 2001/4/20
Y1 - 2001/4/20
N2 - We explore the origin of the color-magnitude relation (CMR) of early-type galaxies in the Virgo Cluster using spectra of very high signal-to-noise ratio for six elliptical galaxies selected along the CMR. The data are analyzed using a new evolutionary stellar population synthesis model to generate galaxy spectra at the resolution given by their velocity dispersions. In particular, we use a new age indicator that is virtually free of the effects of metallicity. We find that the luminosity-weighted mean ages of Virgo ellipticals are greater than ∼8 Gyr and show no clear trend with galaxy luminosity. We also find a positive correlation of metallicity with luminosity, color, and velocity dispersion. We conclude that the CMR is driven primarily by a luminosity-metallicity correlation. However, not all elements increase equally with the total metallicity, and we speculate that the CMR may be driven by both a total metallicity increase and a systematic departure from solar abundance ratios of some elements along the CMR. A full understanding of the role played by the total metallicity, abundance ratios, and age in generating the CMR requires the analysis of spectra of very high quality, such as those reported here, for a larger number of galaxies in Virgo and other clusters.
AB - We explore the origin of the color-magnitude relation (CMR) of early-type galaxies in the Virgo Cluster using spectra of very high signal-to-noise ratio for six elliptical galaxies selected along the CMR. The data are analyzed using a new evolutionary stellar population synthesis model to generate galaxy spectra at the resolution given by their velocity dispersions. In particular, we use a new age indicator that is virtually free of the effects of metallicity. We find that the luminosity-weighted mean ages of Virgo ellipticals are greater than ∼8 Gyr and show no clear trend with galaxy luminosity. We also find a positive correlation of metallicity with luminosity, color, and velocity dispersion. We conclude that the CMR is driven primarily by a luminosity-metallicity correlation. However, not all elements increase equally with the total metallicity, and we speculate that the CMR may be driven by both a total metallicity increase and a systematic departure from solar abundance ratios of some elements along the CMR. A full understanding of the role played by the total metallicity, abundance ratios, and age in generating the CMR requires the analysis of spectra of very high quality, such as those reported here, for a larger number of galaxies in Virgo and other clusters.
KW - Galaxies: abundances
KW - Galaxies: clusters: general
KW - Galaxies: clusters: individual (Virgo)
KW - Galaxies: elliptical and lenticular, cD
KW - Galaxies: evolution
KW - Galaxies: stellar content
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U2 - 10.1086/320019
DO - 10.1086/320019
M3 - Article
AN - SCOPUS:0035918113
SN - 0004-637X
VL - 551
SP - L127-L130
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2 PART 2
ER -