Long Baseline Array Status

Transcription

1 Long Baseline Array Status Cormac Reynolds, Chris Phillips + LBA Team 19 November 2015 CSIRO ASTRONOMY & SPACE SCIENCE

2 LBA LBA VLBI array operated by CSIRO University of Tasmania, Auckland University of Technology and Hartebeesthoek Radio Observatory Parkes (64m), ATCA (5x22m), Mopra (22m), Hobart (26m), Ceduna (30m) Warkworth (12m/30m), Hartebeesthoek (26m/15m), Tidbinbilla (70m/34m), Auscope (12m), ASKAP (12m) EVN joint proposals. EAVN joint observing GHz frequency range ~30 days/year observing IVTW 2016

3 Hartebeesthoek 8000 km IVTW 2016

4 Real-time e-vlbi IVTW 2016

5 Imaging Performance Frequency/MHz Sensitivity/(microJy/beam) 1hr [+ Tid] [25] [20] [25] [90] [220] IVTW 2016

6 The Long Baseline Array (LBA) Regular observations in 20, 13, 6, 3, 1cm bands Also 7mm and 3mm on ATCA, Mopra, Tid Disk-based recorders with e-shipping or/and evlbi on a subset of the array LBADR, Mk5, COTS ( Curtin DAS ) systems LBA reliability greatly enhanced by real-time fringe checks Max. bit-rate 1 Gbps Data correlated on DiFX software correlator Deller et al. 2007, PASP, 119, 318; Deller et al. 2011, PASP, 123, 275 Correlation back in house from Jan 2016 Open VLBI network - proposals 15 June & December Joint application with EVN

7 DAS/Recorder systems - existing LBA DAS (Developed for S2 VCR system) Digital filtering 2 x 64 MHz input IFs (2 pols) = 256 to 1024 Mbps + COTS Computers + Disks Remote disk recording + evlbi Obsolescent Mk4/Mk5/VLBA DAS + MK5A or MK5B recorders Ho, Pk, Tid (older geodetic systems) 16 MHz bands DBBC + Mk5B recorders IVS systems AuScope, NZ, SA 16 MHz bands ASKAP system - ( Brucedas Curtin recorder) COTS computer, Commercial sampler card (Signatec PX1440) 2 x 64 MHz bands = 512 Mbps (could go x2) Flexibility of DiFX a decisive enabler for these heterogeneous systems IVTW 2016

8 The LBA Past 12 months 25 days observing 4 ATNF Antennas (Parkes, ATCA, Mopra, ASKAP) 5 UTAS antennas (Hobart x2, Ceduna, Yarragadee, Katherine) Warkworth x2 antennas (AUT, NZ) Tidbinbilla, Hartebeesthoek Shanghai, Kunming, Tianma65 Median data rate 512 Mbps (Almost) all data e-transferred Fully fledged remote obs Correlator ops returning to CSIRO Pawsey IVTW 2016 Centre

9 LBA Correlator Facility Pawsey Centre Magnus Specs 1488 x 24 core nodes 1097 Teraflops Cray Aries interconnect 72 Gbps per node 64 GB memory per node 3 PB storage (~200 TB for VLBI) Lustre FS: Aggregate read/write speed 70 GB/s 2 Gbps per rank (inferred) #41 on Global Top500 list of supercomputers (2014/11) 450,000 CPU hours secured through merit allocation in 2016 Batch processing (slurm) e-transfer only! IVTW 2016

10 Magnus Performance N Station N nodes Input rate per node /Mpbs Input rate per DS /Mbps Dump rate/mbps Speedup IVTW 2016

11 Magnus Performance Speedup for serial job processing Job IVTW 2016 parallelism x10 typical (~20/1500 nodes per job)

12 PAF VLBI MPIfR have purchased ASKAP ADE PAF for Effelsberg Installed on Parkes 64m for commissioning Uses modified firmware to output 36 dual beam data over 10 Gb Ethernet Dual pol, 336 MHz bandwidth Can capture voltages to disk allowing VLBI 16 bit complex sampling 1 MHz channelization, oversampled by 32/27 (1.185 MHz) 12 IVTW 2016

13 ASKAP Digital Hardware Beam Former Digital Receiver 18.5 khz Nyquist sampled Correlator RFoF 1 MHz channels 188 elements Oversampled Beam Former Digital Receiver

14 MPI PAF changes Digital Receiver Beam Former Same PAF Same samplers No fine filterbank 10 GbE Output

15 VLBI reformatting Need to resample data to Nyquist and wider bands FFT filtering approach used 32/27 MHz data filtered with 64 point FFT 54 central channels kept and contatinated with 6 other channels (7 MHz total) Padded with 0.5 MHz on either end to total of 8 MHz Inverse FFT to single channel voltage time series Resampled to 8 bit and written as VDIF 15 IVTW 2016

16 Parkes PAF - Fringes

17 ATNF Telescope Status Parkes: Large Receiver fleet , , (Multibeam), , , , , , MHz, S/X Limited Frequency Flexibility Building MHz UWB Rx MPI PAF almost commissioned, prospects of permanent PAF LBA DAS and Mark4/Mark5b backends Limited receiver changes IVTW 2016

18 ATNF Telescope Status Mopra: 1.3-3, , 9-9.2, 16-27, 30-50, GHz Recovery from 2013 Bushfire complete CSIRO no longer funding operations Collaboration funding (UNSW, UTAS et al.) for one year 7/3mm and VLBI operations Future uncertain IVTW 2016

19 ATNF Telescope Status ATCA: , , 16-25, 30-50, GHz Some split frequency capability with subarrays. 7/3mm used S/X possible No Mark5 type backend No broadband VLBI capability currently Plans to replace CABB with GPU-based system to provide this ATCA split array capability: 7mm/3mm obs with KVN Reliable 32 GHz fringes ATCA/Mopra/Tid-34m IVTW 2016

20 ATNF Telescope Status LBA + EVN joint proposals First joint observations in June 2016 Kunming + LBA fringes LBA + KVN fringes at 86 GHz LBA + RadioAstron (~50 hours per year) IVTW

21 LBA Calibrator Survey Petrov et al MNRAS, 414, IVTW

22 MASER Astrometry (Krishnan et al.) Structure of spiral arms Proper motion of SMC/LMC

23 Astrometry of protostars (Deller et al.)

24 Wide Field Supernova Remnants (Rampadarath et al.) NGC 253

25 Jet Properties (Kadler et al. 2016) Coincidence of blazar outburst with a PeV-energy neutrino event

26 Thank you CASS/ATNF Cormac Reynolds t E cormac.reynolds@csiro.au w CSIRO ASTRONOMY & SPACE SCIENCE