Title: ALMA sheds new light on dusty starburst galaxies in the early Universe

Speaker:Thomas Greve ,UCL, UK

Time:13th June,3:00pm

Location:3rd floor Lecture Theatre

Abstract:

　  The now well-known discovery of a significant population of highly dust-obscured, star forming galaxies at z > 1 - made more than a decade ago using the famous submillimeter camera, SCUBA - marked the beginning of an extremely exciting and rich area of research that continues to this day. One of the latest developments has been the finding of high-z galaxies ten times more submillimeter-bright than the SCUBA sources. The rarity of these 'new' sources (< 0.1 per sq. degree) is the reason they were missed by the relatively modest survey areas covered by SCUBA and its contemporary cameras. Their discovery had to wait for truly large-scale (>1000s of sq. degrees) millimeter and sub-millimeter surveys such as the ones recently carried out by the 10m South Pole Telescope (SPT) and the Herschel Space Observatory.
　  In this talk I will present the some of the results from our comprehensive multi-wavelength followup campaign of the ultra-bright sources uncovered by the SPT. In line with theoretical expectations we find that they are strongly lensed (magnification factors >10) IR-luminous dusty galaxies, powered by star formation. A large fraction (>30%) have optical/UV and/or CO line spectroscopic redshifts >4, indicating that the fraction of dusty starburst galaxies at high redshift is far greater than previously thought.