Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy

Details Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy

2009-09-29

arxiv.org/abs/0909.5385v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

7 pages, 3 figures, accepted for publication in ApJL

Scientific paper

The study of stellar populations in early-type galaxies in different environments is a powerful tool for constraining their star formation histories. This study has been traditionally restricted to the optical range, where dwarfs around the turn-off and stars at the base of the RGB dominate the integrated light at all ages. The near-infrared spectral range is especially interesting since in the presence of an intermediate-age population, AGB stars are the main contributors. In this letter, we measure the near-infrared indices NaI and D$_{\rm CO}$ for a sample of 12 early-type galaxies in low density environments and compare them with the Fornax galaxy sample presented by Silva et al. (2008). The analysis of these indices in combination with Lick/IDS indices in the optical range reveals i) the NaI index is a metallicity indicator as good as C4668 in the optical range, and ii) D$_{\rm CO}$ is a tracer of intermediate-age stellar populations. We find that low-mass galaxies in low density environments show higher NaI and D$_{\rm CO}$ than those located in Fornax cluster, which points towards a late stage of star formation for the galaxies in less dense environments, in agreement with results from other studies using independent methods.

Affiliated with

Also associated with

No associations

Rating

Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Evidence for intermediate-age stellar populations in early-type galaxies from K-band spectroscopy will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-665096