Durham August 07 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:
Durham August 07 A lovely bunch
Durham August 07 1.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 sources (galaxies) Area 3.2x10 -3 deg 2 Area sky deg 2 Sandage’s goal is detection of galaxies (and stars) at all wavelengths
Durham August 07 Current state of the art in surveys
Durham August 07 Highlights from SDSS 1. Baryonic acoustic oscillations
Durham August 07 Highlights from SDSS 2. High-redshift z>6 quasars
Durham August 07 Highlights from SDSS 3. Structure in the Milky Way halo
Durham August 07 1,2,3 made possible by archive tool
Durham August 07 Highlights from 2MASS 1. All sky atlases
Durham August 07 Highlights from 2MASS 2. Brown dwarfs
Durham August 07 Highlights from 2MASS 2. 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 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 Technical issues
Durham August Technical issues 4x2048x2048 Hawaii II arrays 0.4 arcsec pixels 0.21 sq.degs / exposure Filters: Z,Y,J,H,K,H 2 -S(1),Br-g 1 deg 2 K=19.5 / hr (5sig) etendue 2.38 m 2 deg 2
Durham August 07 UKIRT Wide Field Camera (WFCAM)
Durham August 07 UKIDSS design 5 elements of UKIDSS Large Area SurveyLASYJHK18.4K4000 s.d.262nExGal Deep Extragalactic SurveyDXSJK ExGal Ultra Deep SurveyUDSJHK ExGal Galactic Plane SurveyGPSJHK Gal Galactic Clusters SurveyGCSZYJHK Gal
Durham August 07 UKIDSS design Large Area SurveySDSS near-ir photom, Y dwarfs, KX quasars, z=7 quasars Deep Extragalactic SurveyMultiwavelength fields, the Universe at 1<z<1.5, FMOS spec Ultra Deep SurveyMultiwavelength field SXDS, the Universe at z=3 Galactic Plane SurveyGalactic-plane atlas -5<b<+5 Galactic Clusters SurveyUniversality of the stellar IMF
Durham August 07 UKIDSS design ESO public survey 1000 nights UKIRT over 7yrs UKIDSS = 100 X 2MASS near-ir SDSS began 2005 May 13 surveyP/P 2MASS V/V 2MASS LAS297.0 GPS407.2 GCS122.5 DXS312.2 UDS270.8 total
Durham August 07 2MASS
Durham August 07 Headline science: z>6.4 quasars SDSS limit z=6.4 z=6 quasar spectra indicate reionisation nearly complete by z=6.2
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 dwarfs ULAS J0034 the coolest brown dwarf
Durham August 07 Data access 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