Astronomy and Astrophysics – Astrophysics
Scientific paper
2008-08-21
Astronomy and Astrophysics
Astrophysics
11 pages, 8 figures. Accepted for publication in MNRAS. This replacement has mainly cosmetic textual changes but the model in
Scientific paper
10.1111/j.1365-2966.2008.14080.x
We use 16 micron, Spitzer-IRS, blue peakup photometry of 50 early-type galaxies in the Coma cluster to define the mid-infrared colour-magnitude relation. We compare with recent simple stellar population models that include the mid-infrared emission from the extended, dusty envelopes of evolved stars. The Ks-[16] colour in these models is very sensitive to the relative population of dusty Asymptotic Giant Branch (AGB) stars. We find that the passively evolving early-type galaxies define a sequence of approximately constant age (~10 Gyr) with varying metallicity. Several galaxies that lie on the optical/near-infrared colour-magnitude relation do not lie on the mid-infrared relation. This illustrates the sensitivity of the Ks-[16] colour to age. The fact that a colour-magnitude relation is seen in the mid-infrared underlines the extremely passive nature of the majority (68%) of early-type galaxies in the Coma cluster. The corollary of this is that 32% of the early-type galaxies in our sample are not `passive', insofar as they are either significantly younger than 10 Gyr or they have had some rejuvenation episode within the last few Gyr.
Bressan Alberto
Buson Lucio
Clemens M. S.
Granato Gian Luigi
Panuzzo Pasquale
No associations
LandOfFree
The mid-infrared colour-magnitude relation of early-type galaxies in the Coma cluster as measured by Spitzer-IRS 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 The mid-infrared colour-magnitude relation of early-type galaxies in the Coma cluster as measured by Spitzer-IRS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The mid-infrared colour-magnitude relation of early-type galaxies in the Coma cluster as measured by Spitzer-IRS will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-219580