Oral Presentation
Farther away - A new ALMA spectroscopic survey of monstrous dusty star-forming galaxies at high redshifts
Presenter: Chian-Chou (TC) Chen (ASIAA)
Compared to the Milky Way, Submillimeter galaxies (SMGs) are massive dusty star-forming galaxies that are ten times more massive and more than 100 times more active in star formation. SMGs are found to be most prevalent at a time when the rate of mass assembly of the Universe is at its peak, during the epoch so called the cosmic noon (z~1-3), and evidence suggest that they are progenitors of present-day massive ellipticals. Despite their important role in the formation theory of massive galaxies, models have struggled to converge on their formation mechanisms. One key measurement that could help bring significant adcances to our understandings of massive galaxies is the redshift distribution of the brightest SMGs, where the models differ the most in their predictions. In this talk I plan to introduce AS2COSPEC, our new ALMA spectroscopic survey that tackles this issue by measuring spectroscopic redshifts of a complete and well-defined sample of bright SMGs in the COSMOS field. Our initial results show that brighter SMGs are located significantly farther in distance than what physically motivated models have predicted. We suspect that this may be because the models lack halos with sufficiently massive gas reservoirs, which may be caused by either too efficient star formation or too much feedback at even earlier times.
asiaa.sinica.edu.tw