DETECTIONS OF WATER ICE, HYDROCARBONS, AND 3.3 μm PAH IN<i>z</i>∼ 2 ULIRGs
DETECTIONS OF WATER ICE, HYDROCARBONS, AND 3.3 μm PAH IN<i>z</i>∼ 2 ULIRGs
We present the first detections of the 3um water ice and 3.4um amorphous hydrocarbon (HAC) absorption features in z~2 ULIRGs. These are based on deep rest-frame 2-8um Spitzer IRS spectra of 11 sources selected for their appreciable silicate absorption. The HAC-to-silicate ratio for our z~2 sources is typically higher by …