The Population of BzK-selected ULIRGs at z ~ 2

September 2005 • 2005ApJ...631L..13D

Authors • Daddi, E. • Dickinson, M. • Chary, R. • Pope, A. • Morrison, G. • Alexander, D. M. • Bauer, F. E. • Brandt, W. N. • Giavalisco, M. • Ferguson, H. • Lee, K. -S. • Lehmer, B. D. • Papovich, C. • Renzini, A.

Abstract • We investigate the multiwavelength emission of BzK-selected star-forming galaxies at z~2 in the Great Observatories Origins Deep Survey (GOODS) North region. Most (82%) of the sources are individually detected at 24 μm in the Spitzer MIPS imaging, and one-fourth (26%) in the VLA radio data. Significant detections of the individually undetected objects are obtained through stacking in the radio, submillimeter, and X-ray domains. The typical star-forming galaxy with stellar mass ~10¹¹ M_solar at z=2 is an ultraluminous infrared galaxy (ULIRG), with L_IR~(1-2)×10¹² L_solar and star formation rate SFR~200-300 M_solar yr^-1, implying a comoving density of ULIRGs at z=2 at least 3 orders of magnitude above the local one. SFRs derived from the reddening-corrected UV luminosities agree well, on average, with the longer wavelength estimates. The high 24 μm detection rate suggests a relatively large duty cycle for the BzK star-forming phase, which is consistent with the available independent measurements of the space density of passively evolving galaxies at z>1.4. If the IMF at z=2 is similar to the local one, and in particular if it is not top-heavy, this suggests that a substantial fraction of the high-mass tail (>~10¹¹ M_solar) of the galaxy stellar mass function was completed by z~1.4.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2005ApJ...631L..13D
• PDF https://iopscience.iop.org/article/10.1086/496918/pdf
• PREPRINT http://arxiv.org/abs/astro-ph/0507504
• DATA https://irsa.ipac.caltech.edu/bibdata/2005/D/2005ApJ...631L..13D.html
• ELECTR https://doi.org/10.1086%2F496918
• SPIRES http://inspirehep.net/search?p=find+eprint+astro-ph/0507504