2023-02-27 SSG Meeting notes

Special VLASS SSG Meeting on Transients

Feb 26, 2024

1:00pm EDT/11am MDT/17:00 UTC

https://nrao-edu.zoom.us/j/98640259827?pwd=VE1sTjdETlkwY3lDUDJTbGN0THFOQT09

Attendees:

• Kristina Nyland
• Tracy Clarke
• Dillon Dong
• Brian Kent
• Amy Kimball
• Mark Lacy
• Casey Law
• Steven Myers
• Juergen Ott
• Wendy Peters
• Gregory Sivakoff

Task: “Amplify the transient science case in the Epoch 4 white paper”

Deadline: April 30

Epoch 4 white paper: https://www.overleaf.com/6759236491ncyphwxsvwrx#da0716

Topics to discuss:

• Transient science highlights from VLASS so far
• Newborn Accreting Supermassive Black Holes
• Newborn quasar jets (Nyland+20)
• Stellar Explosions
• GRBs (Schroeder+20)
• Merger-driven core collapse SNR (Dong+21)
• Emerging PWN (Dong+23
• Stars
• Hot magnetic stellar flares found in VCSS (Polisensky+23)
• Radio stars (Yiu+23)
• Starts through proper motions (Driessen et al 23)
• Tidal Disruption Events

• A figure demonstrating the benefit of a 4th epoch for transient science still needed
• Current figures from papers start at Figure 6 in draft science case for VLASS 4

• What are the current challenges to doing time domain science with VLASS?
• No Transient Marshal or Transient Alerts interfaces available
• No prompt catalogs

• Recommendations for supporting time domain science in Epoch 4
• Observatory must provide “prompt” source catalogs at the same time as the Quick Look images are released.
• Cache QA catalogs for Epoch 4
• Potential issues into workflow; particular environments of pythons and libraries.
• Identify existing software/tools for multiwavelength/time domain analysis of survey data that can support broader community access to VLASS data, and then educate the community about them.  Examples:
• ESA Sky (sky.esa.int)
• Aladdin-like, quite flexible.
• Legacy Survey
• https://www.legacysurvey.org/viewer#IC%20169
• Key to use IVOA
• TBD

Ideas:

• CSIRO/RACS took an interesting approach.
• https://www.cambridge.org/core/journals/publications-of-the-astronomical-society-of-australia/article/rapid-askap-continuum-survey-v-cataloguing-the-sky-at-1-3675-mhz-and-the-second-data-release-of-racsmid/42CC05A854F5FCD310A87FAEA1E5F578
• High False Negative / Low False Positive on Transients
• A clear text file that notifies users that an image has been uploaded, or something similar added to the observation status tool.
• For instance, having a version of the observation status text file that is based on a 1 degree by 1 degree image would be useful for the non-power users.
• Need for Forced Aperture Photometry on Demand Tool or other on Demand Tools (Externally provided) - Undiscussed

Action Items

• CIRADA Cutout Service
• Need to update for Epoch 3
• Prototype NRAO requirements on CIRADA, assuming Greg can get the ok for this
• Dillon Dong and Greg Sivakoff to work on this

• Transient Marshall
• Transient Alerts