Ancillary Study Update: Memory & Alzheimer's Disease by Timothy Hughes, PhD
This study led by Timothy Hughes, PhD, focuses on understanding the relationship between micro- and macro-vascular risk factors and dementia pathology in Alzheimer's disease. With a sample size of 540 participants, cognitive testing, brain imaging, and cognitive adjudication processes are conducted to investigate AD risk factors.Feedback, comments for Science, Research, Study Update welcome.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
Southern Hemisphere Long Baseline Array Current and Future Chris Phillips| 12 Feb 2021 Australia s National Science Agency
Long Baseline Array Partnership CSIRO, UTas, AUT, SARAO Some collaboration with EVN and Asian telescopes in Asia Maximum bit rate 1 Gbps (64MHz x 2IFs x 2bits x 2pols x 2Nyquist) Traditionally operated in 4 5 blocks of 5 6 days per year Need to install receivers in Parkes focus cabin Use more compact ATCA configurations Data correlated using DiFX software correlator at Pawsey Supercomputing Centre LBA-GMRT | Chris Phillips 2 |
LBA Frequencies Institution Telescope 1.4 GHz 2.3 4.8 6.7 8.4 22 32 86 GHz S/X Parkes 64m ATNF y y y y y y y ATCA 5 x 22m ATNF y y y y y y y y Mopra 22m ATNF y y y y y y y y Tidbinbilla 70m CDSCC y y y y y Tidbinbilla 34m CDSCC y y y Hobart 26m UTas y y y y y y y Ceduna 30m UTas y y y y y y AuScope 3 x 12m UTas y y y y y Hartebeesthoek 26m SARAO (1.6) y y y y y y Warkworth 12/30m AUT y y y y LBA-GMRT | Chris Phillips 3 |
LBA Imaging Performance AtCdHoMpPk Frequency/MHz Sensitivity/(microJy/beam) 1hr [+ Tid] 1400 45 [25] 2300 40 [20] 4800 65 +HhKeYgTiWw 8400 50 [25] 22000 230 [90] 32000 [220] LBA-GMRT | Chris Phillips 4 |
The LBA Correlator @ Pawsey Magnus Specs 1488 x 24 core nodes 1097 Teraflops Cray Aries interconnect 72 Gbps per node #41 on Global Top500 list of supercomputers (2014/11) 200,000 CPU hours secured through merit allocation in 2020 $70 million upgrade of full supercomputing suite in 2021 LBA-GMRT | Chris Phillips 5 |
Access to the LBA An open call for proposals is made in mid-June and mid-November Telescope time can also be purchased (Breakthrough Listen, CAS, NASA) LBA-GMRT | Chris Phillips 6 |
Enhancing LBA capabilities Ultra-Wide-band Low (0.7 4.0 GHz) receiver installed at Parkes CryoPAF (0.7 2.0 GHz) being built for Parkes Allows simultaneous observations of target and nearby phase calibrators Ultra-Wide-band High (4 15 and 15 27 GHz) under consideration for Parkes Replacement of ATCA correlator with GPU backend started (BIGCAT) Enable much wider bandwidths for VLBI Tied array mode for ASKAP planned (0.7-1.8 GHz) ASKAP-Parkes-uGMRT (FAST?) open up 700-1400 MHz window LBA-GMRT | Chris Phillips 7 |
LAMBDA MWA Style dipole Bluering digital processing RFSoC Sampler/FPGA Channelisation+BeamForming $US190/K 256 dipoles Locate at existing LBA observatories? Saves on site costs (power, network etc) Possibly near existing networks Unfunded See George Heald s talk LBA-GMRT | Chris Phillips 8 |
LBA GMRT Ghana SKA/MeerKAT LBA + GMRT + SKAmid LBA-GMRT | Chris Phillips 9 |
LBA GMRT Ghana SKA/MeerKAT LBA-GMRT | Chris Phillips 10 |
LBA GMRT Ghana SKA/MeerKAT LBA-GMRT | Chris Phillips 11 |
LBA GMRT Shanghai SKA/MWA LBA + GMRT + SKAlow Note no current LBA antenna at these frequencies LBA-GMRT | Chris Phillips 12 |
LBA GMRT Shanghai SKA/MWA LBA-GMRT | Chris Phillips 13 |
LBA GMRT Shanghai SKA/MWA LBA-GMRT | Chris Phillips 14 |
SKA - Global EVN LBA SKA Cross array
Southern Hemisphere VLBI uGMRT will add valuable baselines and sensitivity to LBA science today SKA is coming VLBI follow up vital for many areas of SKA science (and ASKAP and CTA) SKA has no long baselines, SKA VLBI depends on existing telescopes LBA vital for Southern Hemisphere SKA-VLBI ideally global uGMRT will make a valuable link between LBA and SKA
Thank you Astronomy and Space Science Chris Phillips Lead Scientist, Long Baseline Array +61 2 9372 4608 Chris.Phillips@csiro.au www.csiro.au/atnf Australia s National Science Agency
Ultra-wideband Receiver (UWL) Quadridge design Central core of dielectric 700 MHz 4.2 GHz ~21K Tsys Aluminium Fused Quartz PTFE LBA-GMRT | Chris Phillips 18 |
Cryogenically Cooled PAF Mark III cryogenically cooled "Rocket" PAF Prototype on dish 2016 700 2000 MHz Sub 20K Tsys Design well underway Feed array performance comparison System? Temperature/Efficiency? MPIPAF? ASKAP PAF Cryogenic? rocket? PAF? (est.)? MPIPAF? ASKAP PAF Parkes? mul+beam? (T/ )? Cryogenic? rocket? PAF? (est)? Parkes? mul+beam? LBA-GMRT | Chris Phillips 19 | Chippendale? et? al.? (arXiv:1606.03533)? PHISCC2017 Pune 30
Parkes UWB Mid/High Based on UWL and ATCA 4 12 GHz system Utilizing much of the UWL system Samplers, Back-end, GPUs, Software 2 Bands: 4.0 15.4 GHz, 15.4 26.9 GHz Using 12 UWB digitizers (6 per polarisation) 4 24 GHz system may be possible but does not work well with dish surface Not currently funded LBA-GMRT | Chris Phillips 20 |
BIGCAT ATCA Digital backend upgrade 8 GHz bandwidth, GPU based processing Xilinx RFSoC FPGA/digitizer 8x 4 GSps with FPGA fabric Coarse (128 MHz) filterbank 100 Gbps Ethernet packetizer 16 dual GPU servers (32 GPU) GPU fine channelizer, cross correlation gCorr GPU correlator demonstrated LBA-GMRT | Chris Phillips 21 |
Australia Telescope Compact Array (ATCA) Array of six 22m antenna 6 km maximum baseline 3 km east-west track with 214 m northern spur 1.1 105 GHz frequency coverage 4 GHz bandwidth backend Only 128 MHz for VLBI 8 GHz BIGCAT backend coming LBA-GMRT | Chris Phillips 22 |
Parkes 64m prime focus 700 MHz 26 GHz Opened 1961, continual upgrades and evolution Ultra-Wideband Low (UWL) 700 MHz 4 GHz contiguous Cryogenically cooled PAF 700 1900 MHz LBA-GMRT | Chris Phillips 23 |
AuScope 3x 12m Cassegrain antenna Katherine (NT), Yarragadee (WA) and Hobart (Tas) Katherine and Yarragedee 2 14 GHz Rx First VGOS fringes earlier this year Work with Warkworth 12m Part of IVS and separate Southern Hemisphere geodesy Independent UTas VLBI array with Ceduna and Hobart 26m LBA-GMRT | Chris Phillips 24 |
