AN ACCOUNTING OF THE DUST-OBSCURED STAR FORMATION AND ACCRETION HISTORIES OVER THE LAST {approx}11 BILLION YEARS
- Spitzer Science Center, MC 314-6, California Institute of Technology, Pasadena, CA 91125 (United States)
- National Optical Astronomy Observatory, Tucson, AZ 85719 (United States)
- National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States)
- Institute of Astronomy and Astrophysics, Academia Sinica, Taipei 106, Taiwan (China)
We report on an accounting of the star-formation- and accretion-driven energetics of 24 {mu}m-detected sources in the Great Observatories Origins Deep Survey-North field. For sources having infrared (IR; 8-1000 {mu}m) luminosities {approx}>3 x 10{sup 12} L{sub sun} when derived by fitting local spectral energy distributions (SEDs) to 24 {mu}m photometry alone, we find these IR luminosity estimates to be a factor of {approx}4 times larger than those estimated when the SED fitting includes additional 16 and 70 {mu}m data (and in some cases mid-IR spectroscopy and 850 {mu}m data). This discrepancy arises from the fact that high-luminosity sources at z >> 0 appear to have far- to mid-IR ratios, as well as aromatic feature equivalent widths, typical of lower luminosity galaxies in the local universe. Using our improved estimates for IR luminosity and active galactic nucleus (AGN) contributions, we investigate the evolution of the IR luminosity density versus redshift arising from star formation and AGN processes alone. We find that, within the uncertainties, the total star-formation-driven IR luminosity density is constant between 1.15 {approx}< z {approx}< 2.35, although our results suggest a slightly larger value at z {approx}> 2. AGNs appear to account for {approx}<18% of the total IR luminosity density integrated between 0 {approx}< z {approx}< 2.35, contributing {approx}<25% at each epoch. Luminous infrared galaxies (LIRGs; 10{sup 11} L{sub sun} {<=} L{sub IR} < 10{sup 12} L{sub sun}) appear to dominate the star formation rate density along with normal star-forming galaxies (L{sub IR} < 10{sup 11} L{sub sun}) between 0.6 {approx}< z {approx}< 1.15. Once beyond z {approx}> 2, the contribution from ultraluminous infrared galaxies (L{sub IR} {>=} 10{sup 12} L{sub sun}) becomes comparable with that of LIRGs. Using our improved IR luminosity estimates, we find existing calibrations for UV extinction corrections based on measurements of the UV spectral slope typically overcorrect UV luminosities by a factor of {approx}2, on average, for our sample of 24 {mu}m-selected sources; accordingly we have derived a new UV extinction correction more appropriate for our sample.
- OSTI ID:
- 21576843
- Journal Information:
- Astrophysical Journal, Vol. 732, Issue 2; Other Information: DOI: 10.1088/0004-637X/732/2/126; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
MID-IR LUMINOSITIES AND UV/OPTICAL STAR FORMATION RATES AT z < 1.4
SPECTRAL ENERGY DISTRIBUTIONS OF LOCAL LUMINOUS AND ULTRALUMINOUS INFRARED GALAXIES