THE S{sup 4}G PERSPECTIVE ON CIRCUMSTELLAR DUST EXTINCTION OF ASYMPTOTIC GIANT BRANCH STARS IN M100

Journal Article · Sun Apr 01 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/748/2/L30· OSTI ID:22047929

Meidt, Sharon E; Schinnerer, Eva ^[1]; Munoz-Mateos, Juan-Carlos; Kim, Taehyun ^[2]; Holwerda, Benne ^[3]; Ho, Luis C; Madore, Barry F; Sheth, Kartik; Menendez-Delmestre, Karin; Seibert, Mark ^[4]; Knapen, Johan H ^[5]; Bosma, Albert; Athanassoula, E ^[6]; Hinz, Joannah L ^[7]; Regan, Michael ^[8]; De Paz, Armando Gil ^[9]; Mizusawa, Trisha ^[10]; Gadotti, Dimitri A ^[11]; Laurikainen, Eija; Salo, Heikki ^[12] ; others, and

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1. Max-Planck-Institut fuer Astronomie/Koenigstuhl 17, D-69117 Heidelberg (Germany)
2. National Radio Astronomy Observatory, Charlottesville, VA (United States)
3. European Space Agency, ESTEC, Keplerlaan 1, 2200 AG, Noordwijk (Netherlands)
4. The Observatories of the Carnegie Institution for Science, Pasadena, CA (United States)
5. Instituto de Astrofisica de Canarias, Tenerife (Spain)
6. Laboratoire d'Astrophysique de Marseille (LAM), Marseille (France)
7. Department of Astronomy, University of Arizona, Tucson, AZ (United States)
8. Space Telescope Science Institute, Baltimore, MD (United States)
9. Departamento de Astrofisica, Universidad Complutense Madrid, Madrid (Spain)
10. Spitzer Science Center, Pasadena, CA (United States)
11. European Southern Observatory, Santiago (Chile)
12. Astronomy Division, Department of Physical Sciences, University of Oulu, Oulu (Finland)

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 {approx}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 {approx}0.5 mag extinction estimated here may be sufficient to reduce the AGB contribution in the (rest-frame) K band from {approx}70%, as predicted in the latest generation of synthesis models, to {approx}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.

• OSTI ID: 22047929
• Journal Information: Astrophysical Journal Letters, Vol. 748, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AGE ESTIMATION
ASTRONOMY
ASTROPHYSICS
BRIGHTNESS
COSMIC DUST
COSMOCHEMISTRY
ENERGY SPECTRA
GALAXIES
GIANT STARS
INFRARED SPECTRA
MASS
NEAR INFRARED RADIATION
STAR CLUSTERS
VISIBLE RADIATION