The Mid-Infrared Luminosities of Normal Galaxies over Cosmic Time

Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0


6 pages, 4 figures, Accepted for publication in Astrophysical Journal Letters

Scientific paper

Modern population synthesis models estimate that 50% of the restframe K-band light is produced by TP-AGB stars during the first Gyr of a stellar population, with a substantial fraction continuing to be produced by the TP-AGB over a Hubble time. Between 0.2 and 1.5 Gyr, intermediate mass stars evolve into TP-AGB C stars which, due to significant amounts of circumstellar dust, emit half their energy in the mid-IR. We combine these results using published mid-IR colors of Galactic TP-AGB M and C stars to construct simple models for exploring the contribution of the TP-AGB to 24micron data as a function of stellar population age. We compare these empirical models with an ensemble of galaxies in the CDFS from z=0 to z=2, and with high quality imaging in M81. Within the uncertainties, the TP-AGB appears responsible for a substantial fraction of the mid-IR luminosities of galaxies from z=0 to z=2, the maximum redshift to which we can test our hypothesis, while, at the same time, our models reproduce much of the detailed structure observed in mid-IR imaging of M81. The mid-IR is a good diagnostic of star formation over timescales of ~1.5 Gyr, but this implies that on-going star formation rates at z=1 may be overestimated by factors of ~1.5-6, depending on the nature of star formation events. Our results, if confirmed through subsequent work, have strong implications for the star formation rate density of the universe and the growth of stellar mass over time.

No associations


Say what you really think

Search for scientists and scientific papers. Rate them and share your experience with other people.


The Mid-Infrared Luminosities of Normal Galaxies over Cosmic Time 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 Luminosities of Normal Galaxies over Cosmic Time, we encourage you to share that experience with our community. Your opinion is very important and The Mid-Infrared Luminosities of Normal Galaxies over Cosmic Time will most certainly appreciate the feedback.

Rate now


Profile ID: LFWR-SCP-O-667383

All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.