LBA Calibrator Survey Chris Phillips eVLBI Project Scientist 23 July 2009
ATCA Hobart Sydney Ceduna ASKAP The LBA Perth Melbourne Tidbinbilla Mopra Parkes
The LBA 6 telescopes within Australia Parkes, 64m ATCA, 5x22m phased array Mopra, 22m Hobart, 26m Ceduna, 30m Tidbinbilla, 34m&70m Also Hart, Kokee, TIGO, O’Higgins, Shanghai, Kashima 1-20 GHz Data rates up to 1 Gbps LBADR recording system (Mark5b mode) eVLBI up to 1 Gbps Pa, At, Mp, Ho ( Mbps) CSIRO. eVLBI-Aus
LBA Operations Coordinated VLBI for 3 weeks/year 3-4 dedicated sessions/year Fixed schedule Actual schedule depends on experiment request and TAC grading Correlated using DiFX Correlation contracted to Curtin University (Steve Tingay, Cormac Reynolds, Hayley Bignall) CSIRO. eVLBI-Aus
LBA - Future Wide band DAS 1-2 GHz ATCA CABB commissioned DFB3 Pulsar Backend for Parkes/ATCA AuScope 3x12m for geodesy WA, NT and Tasmania S/X only No operational funds for astronomy CSIRO. eVLBI-Aus
ASKAP Number of dishes36 Dish diameter 12m Max baseline 6km Resolution30 Sensitivity65 m 2 /K Observing frequency700 – 1800 MHz Field of View30 deg 2 Processed Bandwidth300 MHz Multiple VLBI beams Up to 30, requested at least 2 Combined with cluster-cluster VLBI at other stations Parkes multibeam, ATCA array, Hobart 12m CSIRO. eVLBI-Aus
LBA Astrometry Adam Deller’s PhD Thesis Parallaxes to 7 pulsars J : Most accurate pulsar distance to date 1E –5408 magnetar propermotion 6.7 GHz methanol maser parallax H 2 0 maser proper motion in LMC CSIRO. eVLBI-Aus
LBA Astrometry – The Problem CSIRO. eVLBI-Aus
AT20G All Southern sky 20 GHz survey South of Dec 0 8 GHz bandwidth Analog correlator 3 antenna Sensitivity limit ~50 mJy CSIRO. eVLBI-Aus
Survey Design Wideband (8 GHz) analogue correlator Fast scan rate: 15°/min at meridian Follow-ups at 4.8, 8.6 & 20 GHz to confirm detection and for spectral info
Survey Parameters Survey Frequency (GHz) Source # Area (sq. Deg.) S lim (mJy) Taylor et al C (Waldram et al ) 15 (22, 43) WMAP (Wright et al. 2008)23, 33, 41, 61, Full Sky (40000) 1000 AT20G20 (4.8,8.6)5800½ Sky (20000)50
LBA Calibrator Survey Using AT20G as a basis for sample to increase density of Southern calibrators σ > S(8.4 GHz) > 190 mJy Dec < -40 Correlated at Bonn Native Mark5A, Mark5B, translated Mark5b shipped electronically Processed with CALC/Solve by Leonid Petrov 8 GHz only – limited by LBA DAS 4x 24hr observed 3x 24hr correlated/analyzed CSIRO. eVLBI-Aus
LBA Calibrator Survey - Results 422 new sources observed 326 processed 317 detections 97.2% detection rate 4 more epochs proposed CSIRO. eVLBI-Aus
Results CSIRO. eVLBI-Aus Before Now Final
Results CSIRO. eVLBI-Aus
Probability of Close Calibrator Zone [-90, -40][+40, +90] Jan 2008Now2010Now 2deg radius21.2%57.8%78.0%73.4% 3deg radius41.2%84.4%96.2%95.0% 4deg radius60.5%96.0%99.5%99.6% # objects CSIRO. eVLBI-Aus
Results – Formal Errors CSIRO. eVLBI-Aus
Compactness CSIRO. eVLBI-Aus
Contact Us Phone: or Web: Thank you ATNF Chris Phillips eVLBI Project Scientist Phone: Web: