Detecting Faint Galaxies by Stacking at 24 m Academic Article uri icon


  • We stack Spitzer 24 m images for 7000 galaxies with 0.1 z < 1 in the Chandra Deep Field South to probe the thermal dust emission in low-luminosity galaxies over this redshift range. Through stacking, we can detect mean 24 m fluxes that are more than an order of magnitude below the individual detection limit. We find that the correlations for low- and moderate-luminosity galaxies between the average LIR/LUV and rest-frame B-band luminosity, and between the star formation rate (SFR) and LIR/LUV, are similar to those in the local universe. This verifies that oft-used assumption in deep UV/optical surveys that the dust obscuration - SFR relation for galaxies with SFR 20 M yr-1 varies little with epoch. We have used this relation to derive the cosmic IR luminosity density from z = 1 to z = 0.1. The results also demonstrate directly that little of the bolometric luminosity of the galaxy population arises from the faint end of the luminosity function, indicating a relatively flat faint-end slope of the IR luminosity function with a power-law index of 1.2 0.3. 2006. The American Astronomical Society. All rights reserved.

published proceedings

  • The Astrophysical Journal

author list (cited authors)

  • Zheng, X. Z., Bell, E. F., Rix, H., Papovich, C., Le Floch, E., Rieke, G. H., & Prez-Gonzlez, P. G.

citation count

  • 35

complete list of authors

  • Zheng, XZ||Bell, Eric F||Rix, Hans-Walter||Papovich, Casey||Le Floc’h, Emeric||Rieke, GH||Pérez-González, PG

publication date

  • April 2006