BEGIN:VCALENDAR VERSION:2.0 CALSCALE:GREGORIAN PRODID:UW-Madison-Physics-Events BEGIN:VEVENT SEQUENCE:0 UID:UW-Physics-Event-3335 DTSTART:20140424T203000Z DTEND:20140424T100000Z DTSTAMP:20260419T193440Z LAST-MODIFIED:20140324T191339Z LOCATION:4421 Sterling Hall SUMMARY:Deep Surveys with GISMO : Searching for submillimeter galaxies at the highest redshifts \, Astronomy Colloquium\, Johannes Staguhn\, John Hopkins University DESCRIPTION:
\nThe GISMO 2 mm camera at the IRAM 30m telescope is available to the astronomical community through the semi-annual IRAM c all for proposals. GISMO provides a general capability across a wide r ange of astronomical sources\, including observations of galactic dust and free-free emission\, the characterization of the SEDs of nearby g alaxies\, and detecting dusty galaxies at high redshifts. The 2 mm ban d is in particular well suited to trace the first dusty galaxies in th e universe\, since their redshifted SEDs peak close to GISMO's observi ng frequency\, whereas the medium redshift galaxy foreground is almost invisible in this band. This effect makes GISMO's deep field observat ions a valuable complement\, rather than a redundancy\, to the HERSCHE L far-infrared and sub-mm surveys. There are two ongoing deep sky surv eys with GISMO. Following a brief summary of a sample of current proje cts\, I will describe one of those surveys in detail: the GISMO Deep F ield (GDF) survey\, which is centered on the Hubble Deep Field North. This survey by now has reached the confusion limit (we measure a confu sion noise of 60 microJy) and we have extracted 12 + 3 sources in a 7 arcminute wide field\, of which roughly half have known submillimeter galaxy counterparts\, including the enigmatic submillimeter galaxy SC UBA-850.1. Our detailed statistical analysis of the GDF data provides a solid estimate of the expected rate of false detections among those source identifications. Furthermore\, numerical simulations were used \, to estimate the "completeness" of our set of extracted sources. A c omparison of our observations with model predictions shows that our re sults are in good agreement with galaxy count models. Simple models pr edict an appreciable number to be at very high redshifts (z~5-6 and ab ove) with intrinsic luminosities of a few 10^12 L_sol.
\nTargeted GISMO observations of even more extreme high redshift galaxies have be en obtained during our most recent observing run. I will present prel iminary results from these observations\, which have the potential to put strong constraints on the formation of dark matter halos and the p roduction of metals in the early universe.
\n Finally\, I will gi ve an outlook into the future by outlining the variety of science ques tions we anticipate to address with the dual band (1 mm and 2 mm) bolo meter camera GISMO-2\, which we expect will replace GISMO at the IRAM 30 m telescope in the second half of 2014. URL:https://www.physics.wisc.edu/events/?id=3335 END:VEVENT END:VCALENDAR