Quest for COSMOS submillimeter galaxy counterparts using CARMA and VLA:
  Identifying three high-redshift starburst galaxies
  We report on interferometric observations at 1.3 mm at 2"-3" resolution using
the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We
identify multi-wavelength counterparts of three submillimeter galaxies (SMGs;
F(1mm)>5.5 mJy) in the COSMOS field, initially detected with MAMBO and AzTEC
bolometers at low, ~10"-30", resolution. All three sources -- AzTEC/C1, Cosbo-3
and Cosbo-8 -- are identified to coincide with positions of 20 cm radio
sources. Cosbo-3, however, is not associated with the most likely radio
counterpart, closest to the MAMBO source position, but that further away from
it. This illustrates the need for intermediate-resolution (~2") mm-observations
to identify the correct counterparts of single-dish detected SMGs. All of our
three sources become prominent only at NIR wavelengths, and their mm-to-radio
flux based redshifts suggest that they lie at redshifts z>~2. As a proof of
concept, we show that photometric redshifts can be well determined for SMGs,
and we find photometric-redshifts of 5.6+/-1.2, 1.9+0.9(-0.5), and ~4 for
AzTEC/C1, Cosbo-3, and Cosbo-8, respectively. Using these we infer that these
galaxies have radio-based star formation rates of >~1000 Msol/yr, and IR
luminosities of ~10^13 Lsol consistent with properties of high-redshift SMGs.
In summary, our sources reflect a variety of SMG properties in terms of
redshift and clustering, consistent with the framework that SMGs are
progenitors of z~2 and today's passive galaxies.
