The Properties of Microjansky Radio Sources in the HDF-N, SSA13, and SSA22 Fields
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Date
2003-03Author
Chapman, S. C.
Barger, A. J.
Cowie, L. L.
Scott, D.
Borys, C.
Capak, P.
Fomalont, E. B.
Lewis, G. F.
Richards, E. A.
Steffen, A. T.
Wilson, G.
Yun, M.
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Show full item recordAbstract
(abridged) We present multiwavelength observations for a large sample of microjansky radio sources detected in ultradeep 1.4GHz maps centered on the Hubble Deep Field-North (HDF-N) and the Hawaii Survey Fields SSA13 and SSA22. Our spectroscopic redshifts for 169 radio sources reveal a flat median redshift distribution, and these sources are hosted by similarly luminous optical L* galaxies, regardless of redshift. This is a serious concern for radio estimates of the local star formation rate density, as a substantial fraction of the ultraviolet luminosity density is generated by sub-L* galaxies at low redshifts. From our submillimeter measurements for 278 radio sources, we find error-weighted mean 850micron fluxes of 1.72$\pm$0.09 mJy for the total sample, 2.37$\pm$0.13 mJy for the optically-faint (I>23.5) subsample, and 1.04$\pm$0.13 mJy for the optically-bright (I3\sigma) detect in the submillimeter 50 of the radio sources, 38 with I>23.5. Spectroscopic redshifts for three of the I23.5. We also find that 66\pm7% of the S850>5 mJy (>4\sigma) sources are radio-identified. We find that millimetric redshift estimates at low redshifts are best made with a FIR template intermediate between a Milky Way type galaxy and a starburst galaxy, and at high redshifts with an Arp220 template.
Citation
Chapman, S. C., A. J. Barger, L. L. Cowie, D. Scott, et al. 2003. "The Properties of Microjansky Radio Sources in the HDF-N, SSA13, and SSA22 Fields." The Astrophysical Journal 585(1): 57-66