The local galaxy 8 μm luminosity function

J. S. Huang, M. L.N. Ashby, P. Barmby, M. Brodwin, M. J.I. Brown, N. Caldwell, R. J. Cool, P. Eisenhardt, D. Eisenstein, G. G. Fazio, E. Le Floc'h, P. Green, C. S. Kochanek, Nanyao Lu, M. A. Pahre, D. Rigopoulou, J. L. Rosenberg, H. A. Smith, Z. Wang, C. N.A. WillmerS. P. Willner

Research output: Contribution to journalArticlepeer-review

54 Scopus citations


A Spitzer Space Telescope survey in the NOAO Deep Wide Field in Bootes provides a complete, 8 μm-selected sample of galaxies to a limiting (Vega) magnitude of 13.5. In the 6.88 deg2 field sampled, 79% of the 4867 galaxies have spectroscopic redshifts, allowing an accurate determination of the local (z < 0.3) galaxy luminosity function. Stellar and dust emission can be separated on the basis of observed galaxy colors. Dust emission (mostly PAH) accounts for 80% of the 8 μm luminosity, stellar photospheres account for 19%, and AGN emission accounts for roughly 1%. A subsample of the 8 μm-selected galaxies have blue, early-type colors, but even most of these have significant PAH emission. The luminosity functions for the total 8 μm luminosity and for the dust emission alone are both well fit by Schechter functions. For the 8 μm luminosity function, the characteristic luminosity is νLν*;(8.0 μm) = 1.8 × 1010 L , while for the dust emission alone it is 1.6 × 10 10 L. The average 8 μm luminosity density at z < 0.3 is 3.1 × 107 L Mpc-3, and the average luminosity density from dust alone is 2.5 × 107 L Mpc-3. This luminosity arises predominantly from galaxies with 8 μm luminosities (νLν) between 2 × 109 and 2 × 1010 L, i.e., normal galaxies, not luminous or ultraluminous infrared galaxies (LIRGs/ULIRGs).

Original languageEnglish (US)
Pages (from-to)840-849
Number of pages10
JournalAstrophysical Journal
Issue number2 I
StatePublished - Aug 1 2007


  • Cosmology: observations
  • Dust, extinction
  • Galaxies: luminosity function, mass function
  • Infrared: galaxies

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'The local galaxy 8 μm luminosity function'. Together they form a unique fingerprint.

Cite this