Astronomy Tea Talk

I present results from a large Keck spectroscopic survey of 0<6 herschel-bright="" galaxies="" selected="" at="" 250um,="" 350um="" and="" 500um.="" this="" is="" the="" first="" large="" sample="" (="">400) of high-z ULIRGs with spectroscopic redshifts since the work on ~<100 SMGs, selected at 850um from SCUBA. I present stacked rest-frame ultraviolet and optical spectra for these Herschel-bright galaxies ("HBGs"), and perform FIR SED fitting to infer FIR luminosities, dust temperatures, emissivities and measure the FIR/radio correlation as a function of redshift. Selected in FIR bands near the peak of blackbody emission (rather than on the Rayleigh Jeans tail, where 850um selection lies), HBGs do not suffer from the same strong dust temperature selection biases as SMGs. As a result, we infer that there are roughly twice as many high-z extreme starbursts than previously thought from submm surveys, which has implications for the enhanced role of extreme starbursts in the star formation history of the Universe. <6>