Ramesh Bhat

Sammy McSweeney

Nick Swainston

Susmita Sett

Isaac Colleran

Willem van Straten

Shi Dai

Ryan Shannon

Ian Morrison

Mengyao Xue

Marcin Sokolowski

Ramesh: Overview

• Nothing has changed in terms of observings

•  

  • ...because MWA is still undergoing upgrade

  • Science commissioning tasks are imminent

  • Then SMART survey will continue, while still in compact config

• PSR #3: J1002-2036

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  • Found using “SMART”er (har har) candidate sifting process, including clustering algorithms that take advantage of complex tied-array beam (for compact config)

  • First estimate: ~10 mJy, possibly steep spectrum

  • 30-sigma detection over 80 mins

• PSR #2: J0026-1955

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  • Active proposals at Parkes and GMRT for follow-up

  • Various issues with localisation

  • Parkes (P1134) followup: Shi managed to pull a detection out of a magic hat, where Ramesh and Nick both had trouble. Found in 2nd harmonic.

  • GMRT Cycle 41 followup: TAC suggested trying full polarimetry. Requires a bit more overhead for calibration, but is an acceptable risk, so we will go for it.

  •  

    • Nulling makes confirmation of source seen in GMRT image a little less straightforward, so we are taking conservative approach.

    • Observation campaign starting soon!

    • Flux of candidate GMRT source suggests possibly steep spectrum source!

  • Priorities

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    • Papers (Nick’s, Sam’s, Ramesh’s) all underway

    • Commissioning the new system

    • Continue SMART observing as soon as system allows!

    • Continue processing and candidate searching (= “pulsar hunting”)

• Discussion:

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  • WvS: offers generic help, e.g. for subpulse drifting analysis, polarimetric calibration

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    • SM: I might reach out about MWA polarimetry

    • Ramesh: GMRT polarimetric is also new, so might need extra help/advice with that.

  • RS: phase-connected timing solution for PSR #2?

  •  

    • Ramesh: Not yet. This is the main objective for Parkes followup data.

    • RS: I can help with that.

    • SD: RFI was really bad, so careful cleaning might help with higher frequencies. Optimistic about timing.

Nick’s update:

• Full 80-minute detection shown for PSR #3

• Not yet found in other obs, but still have other compact config observations to process

• It was found by exploiting compact config tied-array beam pattern, with its grating lobes

• Introduced some smarts to eliminate large number of known pulsar detections by flagging candidates coincident in DM and in nearby tied-array beams

• A few more obs searched, processing is chugging along

• Ramesh: Will be re-applying for supercompute (round is open now, closes in a couple of weeks). Should still be well justified for the next couple of quarters.

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  • Nick concurs

• Ramesh: We will ask for a similar request as last time.

Sam’s update:

• (Will fill in later)

Isaac’s update:

• Showing results for trained networks. ~85% accuracy (on average, across networks).

• SGAN best model even better

• Possibly even better than that because some candidates in validation set were incorrectly labelled.

• Will be implementing trained network into SMART pipeline.

• SD: What is F1-score?

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  • IC: Just one of many metrics.

Paper updates:

Discussion:

• WvS: Recall might be most important metric for ML

• WvS: van Leeuwin 0809 (reference to PSR #2)

• WvS: Looking forward to polarimetry on PSR #2

• SD: Can all SMART detections be detected in continuum imaging? Would be interesting to get spectrum.

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  • RB: Should be possible for subset of pulsars. Susmita has a “golden” image used for testing this kind of thing. Short answer, ~0.5 of pulsars might be able to see in imaging.

  • MS: compact vs extended configuration will make a difference!

  • RB: GMRT probably still best way to get positions