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Session 55 - New Digital Sky Surveys.
Display session, Wednesday, June 10
There is growing evidence that a significant fraction of QSOs in the universe may have remained hidden from optical and UV surveys because of obscuration by dust in and around their nuclei. The Two Micron All-Sky Survey (2MASS) which began northern operations in June 1997, will provide a means to discover many of these obscured QSOs. We have undertaken a pilot search to identify obscured Seyfert galaxies and quasars based on infrared colors in the growing 2MASS database. Our initial results from the first six months of 2MASS operations are very encouraging. In 667 square degrees of survey data (a small, fully processed subset of the > 10,000 sq. deg. of data obtained so far) 165 previously unidentified objects redder than J-K_s>2.0 have been found. Spectroscopic follow-up of 28 candidates has yielded 19 new AGNs, for a success rate of 68%. About 2/3 of these are Seyfert 1s and QSOs and the rest are Seyfert 2 galaxies. The highest redshift 2MASS-discovered QSO has z=1.8 and L_bol \approx 10^12 Lødot. The derived density on the sky of 0.17 per square degree would deliver 6900 new discoveries by the end of the survey. Relaxing the color criterion slightly to J-K_s>1.90 doubles the number of candidates, indicating that there may be > 10,000 of these objects waiting to be discovered.
Program listing for Wednesday