2010ApJ...714.1740M

We present a multi-wavelength, UV-to-radio analysis for a sample of massive (M_*∼ 10¹⁰ M_☉) IRAC- and MIPS 24 µm detected Lyman break galaxies (LBGs) with spectroscopic redshifts z ∼ 3 in the GOODS-North field. For LBGs without individual 24 µm detections, we employ stacking techniques at 24 µm, 1.1 mm, and 1.4 GHz to construct the average UV-to-radio spectral energy distribution and find it to be consistent with that of a luminous infrared galaxy with L_IR= 4.5^+1.1_–2.3x10¹¹ L_☉ and a specific star formation rate of 4.3/Gyr that corresponds to a mass doubling time ∼230 Myr. On the other hand, when considering the 24 µm detected LBGs we find among them galaxies with L_IR>10¹² L_☉, indicating that the space density of z ∼ 3 UV-selected ultra-luminous infrared galaxies (ULIRGs) is ~(1.5±0.5)x10^–5/Mpc3. We compare measurements of star formation rates from data at different wavelengths and find that there is tight correlation (Kendall's τ>99.7%) and excellent agreement between the values derived from dust-corrected UV, mid-IR, millimeter, and radio data for the whole range of L_IR up to L_IR∼ 10¹³ L_☉. This range is greater than that for which the correlation is known to hold at z ∼ 2, possibly due to the lack of significant contribution from polycyclic aromatic hydrocarbons to the 24 µm flux at z ∼ 3. The fact that this agreement is observed for galaxies with L_IR>10¹² L_☉ suggests that star formation in UV-selected ULIRGs, as well as the bulk of star formation activity at this redshift, is not embedded in optically thick regions as seen in local ULIRGs and submillimeter-selected galaxies at z = 2.