Australia Telescope 20 GHz survey (AT20G): An Update
description
Transcript of Australia Telescope 20 GHz survey (AT20G): An Update
Australia Telescope 20 GHz survey (AT20G):Australia Telescope 20 GHz survey (AT20G):An UpdateAn Update
Ron Ekers (ATNF, PI),Sarah Burke(Haverford-Swinburne), Mark Calabretta (ATNF), Gianfranco De Zotti (Padua), Paul Hancock (U Sydney), Carole Jackson (ATNF), Michael Kesteven (ATNF), Marcella Massardi (SISSA-ATNF),
Tara Murphy (U Sydney), Katherine Newton-McGee (U Sydney), Chris Phillips (ATNF), Roberto Ricci (ATNF), Elaine Sadler (U Sydney), Lister Staveley-Smith (ATNF), Mark Walker (MAW Tech), Jasper Wall (UBC),
Warwick Wilson (ATNF)
http://www.atnf.csiro.au/research/AT20G - VSOP-2 09 Mar 2007
• CMB MissionsCMB Missions
• Calibrator manuals for radiotelescopesCalibrator manuals for radiotelescopes
ALMAALMA
ATCAATCA
SKASKA
• Radio Source population studiesRadio Source population studiesWMAP & PLANCKWMAP & PLANCK
MotivationsMotivations
100121612618 GHzRicci et al. 2004
AT20G
22.8 GHz
15 (33) GHz
15 GHz
Freq.
4015,288 38% sky4406AT20G
1000All sky 323Hinshaw et al. 2006 (WMAP3)
25520465Waldram et al. 2003 (9C)
20 6066Taylor et al.2001
Slim (mJy)Area (sq. deg.)Source no.Project
Existing Surveys at high frequencyExisting Surveys at high frequency
WBCORR WBCORR Wide Band analogue correlatorWide Band analogue correlator
Frequency range 16-24 GHzBandwidth 8GHz (8 frequency channels)
All sky in 10(15)degree declination regionsAll sky in 10(15)degree declination regions includes galactic plane
No delay correction possibleNo delay correction possiblescan along the meridian
High scan rateHigh scan rate: 15 deg./min
Sky Coverage
Missing DataMissing Data
Combine the scans to make maps
Candidate Candidate SourcesSources
The SurveyThe Survey Blind scan Calibration Map making Selection criteria LIST OFLIST OF
CANDIDATESCANDIDATES
Follow up Follow up @ 20GHz@ 20GHz
Observation of the candidates LIST OF SOURCESLIST OF SOURCES
Follow up @ Follow up @ 4.8 and 8.6 GHz4.8 and 8.6 GHz
low frequency observations of the confirmed sources
DATA ON EACH SOURCEDATA ON EACH SOURCE
PIPELINE PIPELINE of data analysisof data analysis
flagging calibration data reduction polarization analyses imaging
AT20G CATALOGUEAT20G CATALOGUE
Equal area sky maps of the AT20G follow-up sources (2004-2006)
4406 extragalactic sources detected in 15288 sq. deg.
Polar projection Aitoff projection
AT20G source counts
Integral source countsIntegral source countsNormalized differential countsNormalized differential counts
Spectral index from AT20G 2004-2006
3737 extragalactic sources3737 extragalactic sources 280 extragalactic sources 280 extragalactic sources
All AT20G sampleAll AT20G sample Bright Sample (SBright Sample (S20 20 > 0.5 Jy)> 0.5 Jy)
11%
53%
13%
22%
8% 20%
29% 43%
Massardi et al. 2007 in prep.Massardi et al. 2007 in prep.
AT20G Polarization Properties
5GHz 8GHz 18GHz
Mean 2.43% 2.63% 2.83%
Median 2.19% 2.18% 2.10%
Max 8.02% 9.38% 10.66%
• S20>500mJy; < -30º• ~200 sources observed
5GHz5GHz 8GHz8GHz 18GHz18GHz
Burke et al. 2007 in preparationBurke et al. 2007 in preparation
Gravitational lens search
Spectral index (4.8-8.6 GHz)Spectral index (4.8-8.6 GHz)
-0.5-0.5 00
11
0.50.5
Am
p(6)
/Am
p(no
6)A
mp(
6)/A
mp(
no6)
0619-20540619-2054
1755-21441755-2144
PKS1830-211PKS1830-211
0711-19510711-1951
Plot courtesy of R.ChhetriPlot courtesy of R.Chhetri
•Clean-up follow-ups Clean-up follow-ups (C1049: -90°<dec< -15(C1049: -90°<dec< -15ºº))
•Follow-up of galactic objects Follow-up of galactic objects (UCHII: Murphy et al. 2007 in prep.)(UCHII: Murphy et al. 2007 in prep.)
•3mm follow-up 3mm follow-up (C1392: Sadler et al. 2007 in prep.)(C1392: Sadler et al. 2007 in prep.)
•Variability studies Variability studies (2002-2004: Sadler et al. 2006)(2002-2004: Sadler et al. 2006)
•Polarization studies Polarization studies (C1633: Burke et al. 2007 in prep.)(C1633: Burke et al. 2007 in prep.)
•Upcoming data release Upcoming data release (BSS: Massardi et al. 2007 in prep.)(BSS: Massardi et al. 2007 in prep.)
• Search for grav. lensesSearch for grav. lenses (CLASS in the South: Chhetri et al.)(CLASS in the South: Chhetri et al.)
• ......
The Future of AT20GThe Future of AT20G