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Exploring the Transient Ultraviolet Universe

Event Details

Event Dates: 

Monday, December 3, 2012 - 9:00am

Speaker Name(s): 

Suvi Gezari

Speaker Affiliation(s): 

Johns Hopkins, Dept. of Physics & Astronomy
Seminar Type/Subject

Event Details & Abstract: 

The wide-field ultraviolet (UV) Universe was an unexplored parameter space before the launch of NASA's Galaxy Evolution Explorer (GALEX). I will present results from our effort to systematically study the wide-field UV time domain for the first time with GALEX Time Domain Survey (TDS). GALEX TDS monitored 40 square degrees of sky in the NUV with a cadence of 2 days and a baseline of 3 years, in spatial and temporal coordination with the Pan-STARRS1 Medium Deep Survey (PS1 MDS) in the optical, which provides deep optical imaging and contemporaneous optical transient detections via image differencing. We select over a thousand UV variable and transient sources, with 62% classified as actively accreting supermassive black holes (active galactic nuclei and quasars), and 9% classified as variable and flaring stars (including RR Lyrae and M-dwarf stars). The remaining GALEX TDS sample includes UV-bright extragalactic transients, some of which have been spectroscopically confirmed as young core-collapse supernovae, and flares from the tidal disruption and accretion of a star by an otherwise dormant supermassive black hole. I will conclude with how these fruitful results from the coordinated monitoring of GALEX TDS and PS1 MDS demonstrate the exciting discovery potential of a future wide-field UV space telescope survey in coordination with the next generation of ground-based optical synoptic surveys such as LSST.