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Wide-field surveys, and opportunities in the near-infrared. Steve Warren Imperial College London UKIDSS Survey Scientist. Homework: Lawrence ‘Wide Field Surveys and Astronomical Discovery Space’ arXiv:0704.0809. A lovely bunch. What are surveys useful for?
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Wide-field surveys, and opportunities in the near-infrared Steve Warren Imperial College London UKIDSS Survey Scientist Homework: Lawrence ‘Wide Field Surveys and Astronomical Discovery Space’ arXiv:0704.0809 Durham August 07
A lovely bunch Durham August 07
What are surveys useful for? 2. The current state of the art 3. Some highlights from SDSS and 2MASS 4. Opportunities in the near-infrared with UKIDSS - What is the near-infrared good for? - Technical issues - Two headline science goals 5. The near future Durham August 07
What are surveys useful for? 1. Efficient use of telescope time 2. Archive - things you haven’t thought of 3. Serendipitous discoveries Durham August 07
What are surveys useful for?Discovery of Uranus (1781) Durham August 07
Sandage (telescope proposal) “Not all astronomical sources have been observed at all wavelengths. We propose to remedy this.” Durham August 07
HUDF contains 10040 sources (galaxies) Area 3.2x10-3 deg 2 Area sky 41253 deg2 Sandage’s goal is detection of 1011 galaxies(and 1011 stars) at all wavelengths Durham August 07
Current state of the art in surveys Durham August 07
Highlights from SDSS1. Baryonic acoustic oscillations Durham August 07
Highlights from SDSS2. High-redshift z>6 quasars Durham August 07
Highlights from SDSS3. Structure in the Milky Way halo Durham August 07
1,2,3 made possible by archive tool Durham August 07
Highlights from 2MASS1. All sky atlases Durham August 07
Highlights from 2MASS2. Brown dwarfs Durham August 07
Highlights from 2MASS2. Brown dwarfs Durham August 07
Opportunities in the near-infrared with UKIDSS • 1. What is the near-infrared good for? • 2. Technical issues • 3. Two headline science goals Durham August 07
1. What is the near-infrared good for? • Near-infrared explores the cool, the dust-obscured, • and the high-redshift universe Durham August 07
2MASS too shallow cf SDSS • LAS best for rare objects • DXS, UDS well suited to old • stellar pops at high z • DXS, SWIRE well matched Durham August 07
2. Technical issues Durham August 07
2. Technical issues • 4x2048x2048 Hawaii II arrays • 0.4 arcsec pixels • 0.21 sq.degs / exposure • Filters: Z,Y,J,H,K,H2-S(1),Br-g • 1 deg2 K=19.5 / hr (5sig) • etendue 2.38 m2deg2 Durham August 07
UKIRT Wide Field Camera (WFCAM) Durham August 07
UKIDSS design5 elements of UKIDSS Durham August 07
UKIDSS design Durham August 07
UKIDSS design • ESO public survey • 1000 nights UKIRT over 7yrs • UKIDSS = 100 X 2MASS • near-ir SDSS • began 2005 May 13 Durham August 07
2MASS 2MASS Durham August 07
Headline science: z>6.4 quasars • z=6 quasar spectra indicate reionisation nearly complete by z=6.2 SDSS limit z=6.4 Durham August 07
Headline science: z>6.4 quasars At Y<19.5 expect: 1 quasar z>6 in 150 sq degs 1 quasar z>6.4 in 300 sq degs EDR indicates contamination only 20:1 Durham August 07
Headline science: the search for Y dwarfs Durham August 07
Headline science: the search for Y dwarfs Durham August 07
Headline science: the search for Y dwarfsULAS J0034 the coolest brown dwarf Durham August 07
Data accesshttp://surveys.roe.ac.uk/wsa Flexible query tool providing access to: Images Detection tables Source tables Registration by institution, with approved list monitored by community contact. e.g. imperial.ac.uk get username and pwd from SJW Durham August 07
The near future VISTA near-ir WISE mid-ir Herschel far-ir 2008 2009 2008 Durham August 07