Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 1, 2012 | Published
Journal Article Open

The S^4G Perspective on Circumstellar Dust Extinction of Asymptotic Giant Branch Stars in M100

Abstract

We examine the effect of circumstellar dust extinction on the near-IR (NIR) contribution of asymptotic giant branch (AGB) stars in intermediate-age clusters throughout the disk of M100. For our sample of 17 AGB-dominated clusters we extract optical-to-mid-IR spectral energy distributions (SEDs) and find that NIR brightness is coupled to the mid-IR dust emission in such a way that a significant reduction of AGB light, of up to 1 mag in the K band, follows from extinction by the dust shell formed during this stage. Since the dust optical depth varies with AGB chemistry (C-rich or O-rich), our results suggest that the contribution of AGB stars to the flux from their host clusters will be closely linked to the metallicity and the progenitor mass of the AGB star, to which dust chemistry and mass-loss rate are sensitive. Our sample of clusters—each the analogue of a ~1 Gyr old post-starburst galaxy—has implications within the context of mass and age estimation via SED modeling at high-z: we find that the average ~0.5 mag extinction estimated here may be sufficient to reduce the AGB contribution in the (rest-frame) K band from ~70%, as predicted in the latest generation of synthesis models, to ~35%. Our technique for selecting AGB-dominated clusters in nearby galaxies promises to be effective for discriminating the uncertainties associated with AGB stars in intermediate-age populations that plague age and mass estimation in high-z galaxies.

Additional Information

© 2012 The American Astronomical Society. Received 2011 December 18; accepted 2012 February 29; published 2012 March 19. S.E.M. thanks Arjen van der Wel for discussion and Angela Adamo and Anibal Garcia for their helpful comments on the manuscript. E.A. and A.B. thank the Centre National d'Etudes Spatiales for financial support.

Attached Files

Published - Meidt2012p17952Astrophys_J_Lett.pdf

Files

Meidt2012p17952Astrophys_J_Lett.pdf
Files (365.3 kB)
Name Size Download all
md5:72c5e3ee756f07584787a517fbc86686
365.3 kB Preview Download

Additional details

Created:
August 22, 2023
Modified:
October 17, 2023