Long Baseline Array Chris Phillips LBA Lead Scientist 5 September 2018 CSIRO ASTRONOMY & SPACE SCIENCE

Transcription

1 Long Baseline Array Chris Phillips LBA Lead Scientist 5 September 2018 CSIRO ASTRONOMY & SPACE SCIENCE

2 The Long Baseline Array (LBA) Operated as a National Facility by CSIRO Astronomy & Space Science, in close cooperation with the University of Tasmania, Hartebeesthoek Radio Observatory and Auckland University of Technology Core elements: ATCA (5x22m), Mopra (22m), Parkes (64m), Ceduna (30m), Hobart (26m) + Tidbinbilla (70m & 34m), Warkworth (12m & 30m), Hartebeesthoek (26m & 15m), ASKAP (12m), AuScope (3x12m), plus ad-hoc arrangements with Korea and China. Typically ~25 days observing each year in ~4 sessions Plus RadioAstron survey and imaging experiments, some EVN/global experiments

3 EAVW 2018 LBA Phillips

4 Baseline lengths in km Pa At Mp Ho Cd Hh Yg Ke Ak Ww Ti Pa At Mp Ho Cd Hh Yg Ke Ak Ww Ti

5 The Long Baseline Array (LBA) Regular observations in 20, 13, 6, 3, 1cm bands GHz Not all telescopes support all bands ATCA, Mopra 7 & 3mm, Tid 7mm Disk-based recorders (with most data later streamed to the correlator), evlbi available on subset of the array LBADR, Mk5b and flexbuf recorders Max bit-rate 1Gbps Data correlated on DiFX software correlator at Pawsey supercomputing facility Deller et al. 2007, PASP, 119, 318 (DiFX) Deller et al. 2011, PASP, 123, 275 (DiFX-2)

6 Locations & SEFDs (in Jy) of LBA elements Lat. Long. 20cm 13cm 6cm 3cm 1.5cm 9mm ATCA 5x22m 150 E 30 S ASKAP 1x12m 117 E 26 S Ceduna 30m 134 E 32 S Hobart 26m 147 E 43 S Hart 26m 28 E 26 S Mopra 22m 149 E 31 S Parkes 64m 148 E 33 S Tid 70m 149 E 35 S Tid 34m 149 E 35 S Warkworth 12m 175 E 37 S Warkworth 30m 175 E 37 S

7 LBA Science in a year Measuring accurate position, velocity and distance (via parallax) to objects in our own Galaxy Figure 1: Left 22 GHz water maser emission in G for our absolute proper motion measurements. The spectrum the inset showing an expanded view at high velocities includin of 8.6 GHz radio (Ellingsen et al. 1996) and 10 µm mid infr maser emission in G Methanol masers (filled ci Forster & Caswell 1989) and OH masers (squares Caswel possible bipolar mass loss events. The diagonal line indicates proper motion and magnetic field measurements. Young massive stars, evolved stars, pulsars, gamma ray sources, black holes Accurately measure the structure and rotation of our own Galaxy Figure 2: The 3 D kinematics of the 6.7 GHz methanol (left) and (Sanna et al. 2010). The cones represent the direction and unce It is clear that both varieties trace distinctive structures and ar are concentrated towards the central region of G i the plane, while the methanol masers trace a ring with proper EAVW 2018 LBA Phillips motion measurements is that the maser spot evolution will be u reference. T his will eliminate any biased analysis of the maser using an arbitrary reference point located within the source. T

8 LBA Science in a year (cont) Study the jets of Galactic and extra galactic black holes Study molecular disc around Circinus galaxy using water molecules Long term monitoring of radio jets from gamma ray loud AGN Detection of radio emission towards recent gravitational wave EAVW 2018 LBA Phillips

9 LBA Science in a year (cont) Improve the international radio reference frame (ICRF) Determine if SMBH candidate is binary source Detect radio emission from 90 Jupiter mass brown dwarf star Systematically compare optical and radio positions of galaxies ure 3: Left: Position uncertainties from prior LCS observations (blue point s) and new v561 obserons (gr een point s) after accounting for systematic errors; Right: an an example of a preliminary ge of EAVW a 2018 source LBA observed Phillips in v561a that has never been imaged before. The jet direction is reliably rmined.

10 Current Developments - ASKAP

11 Current Developments Parkes Ultrawideband receivers MHz Rx installed May K Tsys across band 4 GHz-26 GHz planned, not funded Focus cabin digitizers 12 bit quantization GPU based backend Single backend for all modes Adaptive RFI mitigation Investigation new calibration Pseudo random noise, picosecond pulse

12 Current Status: Pulsar Fold Mode Courtesy of W. van Straten EAVW 2018 LBA Phillips 12

13 Current Developments (cont) Parkes cryo-paf funding proposal to be submitted 36 beam backend limited by digital backend 20K Tsys better than current 13 beam multi-beam ATCA GPU backend planning 8 GHz bandwidth Demonstrated viability at GPUhackathon ASKAP tied array beam? PAF VLBI already demonstrated User Parkes-ASKAP experiment in December

14 International Collaborations? Investigating formally joining global VLBI experiments Single proposal requirement Software correlation and disk base recording make array interoperability much easier Should be be doing more Asia-LBA observing? Asian telescopes as part of LBA experiments LBA antenna as part of EAVN? Logistics are not trivial: Data transport (firewalls) Backend/receiver compatibility Educate observers on availability

15 Thank you CASS/ATNF Chris Phillips LBA Lead Scientist t E Chris.Phillips@csiro.au w CSIRO ASTRONOMY & SPACE SCIENCE

16 CODIF CSIRO Oversampled Data Interchange Format Extension to VDIF Based on VDIF2 proposal by Alan Whitney Used with CSIRO PAF at Bonn and Jodrell Added CODIF support to DIFX Used with ASKAP CRAFT project to localize FRBs