2024-11-04 SSG Meeting notes

Date:04 Nov 2024

Link to Video recording

Passcode: hP$7D6zD

VLASS News:

Data processing: Mark and Amy

96% QL processing done
SE imaging in the north in progress
New timeline under development
- gridding is a big bottleneck - investigation into approach using gridded visibilities
- “Re-phasing” to reduce number of w-terms

“Core” processing to be done in 3 years
No Epoch 1.1 SE products
Confluence page has details (link?)
New tools and services to support access to historical surveys (NVSS, FIRST)
Computing resources are being investigated
Key challenge: SECI pipeline requires a lot of memory per job; inconsistent with how HPC resources are set-up
Question by Dillon: why not break-up imaging into smaller patches with less demanding memory requirements?
Comments by Chenoa:

Kristina's undergrad found spiral host galaxy of VLASS variable source, presenting at AAS.

Events/Outreach:

List of outreach idea here
Conference updates?
Winter AAS (National Harbor)
- Mark - general VLASS abstract
- Charlotte’s student will present a poster
- Dillon’s student will present on Stokes V imaging
- Kristina + students will present posters on AGN science involving VLASS

Transients from Space - March 11-13, 2025 at STScI in Baltimore, MD
Radio Transients - 28 July–1 August 2025 at the University of Sydney, Australia
UK SKAO Science Committee Early Career Researcher Group are hosting a Careers webinar for early career researchers in radio astronomy, from 10-11am on Monday 11th November. https://urldefense.com/v3/__https:/www.eventbrite.co.uk/e/uk-radio-astronomy-careers[…]yAzN5Ee2IYkHC47MzQqqpD2nKYWZsQeiBuSiwrfWnttmLlO74TH97gt1M5a8$

Paper update: Kristina

Targeted high-level data product processing (“phase 1”): Steve
- NRAO will solicit feedback from the SSG
- Plan will be finalized by end of 2024
- Notes from previous discussions:
  - 5-10k sq degrees, at least one epoch of full products . . .
  - Limitations on declination/algorithm requirements (need to be above -4 deg dec to avoid need for awproject)
  - Ideally, field(s) should be appropriate for polarization validation
  - Suggestions
    - Stripe 82 (VLASS + POSSUM collaboration?)
    - LOTSS DR2
    - Galactic center
    - Validation fields
    - CDFS
  - Steve's suggestion: 4 → +4 Dec, (T10,T11), 0-24 RA (2900 deg^2)
- Action Item: Lerato and Jennifer asked to share fields for POSSUM validation with NRAO

Dillon’s new tools

New VLASS cutout server API that prioritize speed/efficiency
Prototype available: https://vlasscutouts.ngrok.io/cutout?ra=358.9545833&dec=30.7633750&epoch=2&size=61&outputpix=250&plow=1&pmax=100
Not ready for primetime yet due to data transfer/securuty issues. Dillon is happy to share the code e.g. with CIRADA, who are moving their cutout server to CADC.
Mosaicking would be nice but doesn’t scale well right now (needs Montage)

New Polarimetry data products now available (Lerato)

Details on Slack
Link: tbd
Would be good to have more people checking out results. Best to limit to SNR>8 for reliable RMs.

Future topics (upcoming meetings)

Transient Update
CANDIAPL/CIRADA Update

Jan 2026 AAS Special session on high resolution radio surveys
- VLASS science highlights
- Synergy with other radio surveys
- What is the next VLA survey going to look like?
- Deadline for special sessions is ~spring or summer before
- Call for white papers?

Future meetings: (subject to change; check your email/Slack for updates)

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