Wide-field surveys, and opportunities in the near-infrared

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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 arXiv0704.0809
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A lovely bunch
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• 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

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What are surveys useful for?

• 1. Efficient use of telescope time
• 2. Archive - things you havent thought of
• 3. Serendipitous discoveries

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What are surveys useful for?Discovery of Uranus
(1781)
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Sandage (telescope proposal) Not all
astronomical sources have been observed at all
wavelengths. We propose to remedy this.
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(No Transcript)
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HUDF contains 10040 sources (galaxies) Area
3.2x10-3 deg 2 Area sky 41253 deg2 Sandages goal
is detection of 1011 galaxies (and 1011 stars) at
all wavelengths
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Current state of the art in surveys
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Highlights from SDSS1. Baryonic acoustic
oscillations
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Highlights from SDSS2. High-redshift zgt6 quasars
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Highlights from SDSS3. Structure in the Milky
Way halo
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1,2,3 made possible by archive tool
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Highlights from 2MASS1. All sky atlases
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Highlights from 2MASS2. Brown dwarfs
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Highlights from 2MASS2. Brown dwarfs
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Opportunities in the near-infrared with UKIDSS

• 1. What is the near-infrared good for?
• 2. Technical issues
• 3. Two headline science goals

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1. What is the near-infrared good for?

• Near-infrared explores the cool, the
  dust-obscured,
• and the high-redshift universe

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• 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

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2. Technical issues
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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 K19.5 / hr (5sig)
• etendue 2.38 m2deg2

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UKIRT Wide Field Camera (WFCAM)
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UKIDSS design5 elements of UKIDSS

Large Area Survey LAS YJHK 18.4K 4000 s.d. 262n ExGal
Deep Extragalactic Survey DXS JK 21.0 35 118 ExGal
Ultra Deep Survey UDS JHK 23.0 0.77 296 ExGal
Galactic Plane Survey GPS JHK 19.0 1800 186 Gal
Galactic Clusters Survey GCS ZYJHK 18.7 1200 84 Gal
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UKIDSS design
Large Area Survey SDSS near-ir photom, Y dwarfs, KX quasars, z7 quasars
Deep Extragalactic Survey Multiwavelength fields, the Universe at 1ltzlt1.5, FMOS spec
Ultra Deep Survey Multiwavelength field SXDS, the Universe at z3
Galactic Plane Survey Galactic-plane atlas -5ltblt5
Galactic Clusters Survey Universality of the stellar IMF
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UKIDSS design

• ESO public survey
• 1000 nights UKIRT over 7yrs
• UKIDSS 100 X 2MASS
• near-ir SDSS
• began 2005 May 13

survey P/P2MASS V/V2MASS
LAS 29 7.0
GPS 40 7.2
GCS 12 2.5
DXS 31 2.2
UDS 27 0.8
total 139 19.7
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2MASS
2MASS
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Headline science zgt6.4 quasars

• z6 quasar spectra indicate reionisation nearly
  complete by z6.2

SDSS limit z6.4
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Headline science zgt6.4 quasars
At Ylt19.5 expect 1 quasar zgt6 in 150 sq degs 1
quasar zgt6.4 in 300 sq degs EDR indicates
contamination only 201
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Headline science the search for Y dwarfs
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Headline science the search for Y dwarfs
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Headline science the search for Y dwarfsULAS
J0034 the coolest brown dwarf
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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
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The near future
VISTA near-ir WISE mid-ir
Herschel far-ir 2008
2009 2008