SMART meeting, 30 Jul 202

Present:

• Ramesh Bhat
• Keegan Smith
• Nick Swainston
• Sam McSweeney
• Zhongli Zhang
• Susmita Sett
• Marcin Sokolowski
• Isaac Colleran
• Mengyao Xue
• Ryan Shannon
• Willem van Straten

Update overview (Ramesh):

• Survey ramping up
• 3 student projects connected to SMART survey
• Have been awarded time on OzStar (1.5 million hours), looking ahead to Garrawarla
• 2-3 times speed increase on OzStar (compared to Galaxy)
• Adopted strategy of “quick look, first pass” pipeline constrained by PhD timelines
• Limited DM steps, 5-10 mins of data
• New pulsar (J0036-1033) gives us hope!
• Also important for “quick” turnaround of data processing so that fields can be re-observed if necessary
• 96 known pulsars detected with Keegan’s pipeline
• 5 fields have been processed (although not sifted for candidates)
• Alternative search strategies are being explored (cf Susmita & Marcin’s imaging pipeline)
• ADACS proposal initially turned down, but CIC resources have been allocated
• We have to take advantage of all remaining Phase 2 compact configuration time for data collection
• There will be a proposal call later this year
• At least 60% data is in the can
• By the end, ~3PB, 0.5 million beams, 7 million core hours for 1 round of processing
• Follow-up of J0036-1033 possible with ~10 existing archived VCS observations (both phase 1 and phase 2, extended and compact)
• For localisation, regridding/re-beamforming straightforward task w/out need for re-observing
• Sub-arcminute localisation unlocked
• Efforts to understand polarimetry -- for new pulsar (and more generally)
• Attempts to detect new pulsar in imaging
• So far unsuccessful
• Suggests that pulsar is “low luminosity pulsar”
• Proposal has been put in for Parkes, and will be put in for GMRT (deadline tomorrow)
• Will be basis for short paper

Nick’s update:

• Just about finished processing (quick look) 9 observations.
• Been through 1000’s of candidates
• New Nextflow pipeline:
• Has improved efficiency, uses containers
• Can now process 1 obs per week
• Installed on Garrawarla, Ozstar, and (almost) at SHAO
• ML part of pipeline helps a lot, but still produces many obvious noise candidates
• Working to decentralise candidate ranking (so that it’s not just Nick doing it)
• Also working on Single pulse candidates
• Likes LOFAR single pulse software/pipeline
• Have tried SHAO’s pipeline (STEP?) -- almost working, but indications that it may not be the best choice
• >15 candidates per beam → lots of candidates!!

Marcin’s update:

• Pipeline:
• Offline correlation (1 sec integration), RFI flagging, calibration, and other standard MWA processing, output = Stokes images from XX, YY
• Looking for J0036-1033 in imaging
• RMS 12 mJy (I) and 2.5 mJy (V) images show nothing convincing at pulsar’s location
• Pointing towards pulsar is <5mJy
• Also, GMRT image of same area of sky shows nothing (which gets down to 2.5 mJy/beam)
• Can see other pulsars in the field with same imaging techniqu

Sam’s update:

• LOFAR’s tree classifier
• DM curve, profile, freq-vs-phase, time-vs-phase features
• Generative adversarial networks
• Isaac’s ongoing project
• All available ML tools will feed into database app (with web interface) for human inspection.
• Working with CIC to develop database/web app.

Discussion:

• Fancy tricks for localisation? Follow up with Ryan’s FRB localisation techniques with ASKAP (Ryan to email Nick some Python code). May get down to ~1/10 of a (tied-array) beamwidth in precision.
• Imaging can help weed out nights when ionosphere is very active and moves sources around
• Test gridding method on known pulsar position to get errors
• Not likely for Nick’s pulsar to be in a sidelobe -- sidelobe detections have characteristic frequency dependence.