SPITZER 70/160 μm OBSERVATIONS OF HIGH-REDSHIFT ULIRGs AND HyLIRGs IN THE BOOTES FIELD

We present new 70 and 160 mu m observations of a sample of extremely red (R-[ 24] greater than or similar to 15 mag), midinfrared bright, high-redshift (1.7 less than or similar to z less than or similar to 2.8) galaxies. All targets detected in the far-infrared exhibit rising spectral energy distributions (SEDs) consistent with dust emission from obscured active galactic nuclei (AGNs) and/or star-forming regions in luminous IR galaxies (LIRGs). We find that the SEDs of the high-redshift sources are more similar to canonical AGN-dominated local ultraluminous IR galaxies (ULIRGs) with significant warm dust components than to typical local star-forming ULIRGs. The inferred IR (8-1000 mu m) bolometric luminosities are found to be L-bol similar to 4 x 10(12) L-circle dot to similar to 3 x 10(13) L-circle dot (ULIRGs/hyperluminous IR galaxies (HyLIRGs)), representing the first robust constraints on Lbol for this class of object.