Early Type Galaxies in the Mid Infrared
Abstract
We are performing a systematic study of the properties of early-type galaxies in the mid infrared spectral region with the Spitzer Space Telescope. We present here high S/N Spitzer IRS spectra of 17 Virgo early-type galaxies. Thirteen objects of the sample (76%) show a pronounced broad feature (above 10 microns) which is spatially extended and likely of stellar origin. We argue that this feature is (mostly) due to silicate emission from circumstellar envelopes of asymptotic giant branch (AGB) stars. The remaining 4 objects, namely NGC 4486, NGC 4636, NGC 4550 and NGC 4435, are characterized by various levels and type of activity.
Cite
@article{arxiv.astro-ph/0701620,
title = {Early Type Galaxies in the Mid Infrared},
author = {A. Bressan and P. Panuzzo and L. Silva and L. Buson and M. Clemens and G. L. Granato and R. Rampazzo and J. R. Valdes and O. Vega},
journal= {arXiv preprint arXiv:astro-ph/0701620},
year = {2007}
}
Comments
Comments: 8 pages, to appear in the Proceedings of the Conf. "From Stars to Galaxies: Building the Pieces to Build Up the Universe", Vallenari et al. eds., ASP Conf. Series