Telecon notes, NGVLA Transients/Physics SWG 2014/11/05

(notes taken by PD)

Meeting participants:

Geoff Bower, Paul Demorest, Steve White, Laura Chomiuk, Jim Braatz, Miguel Morales, Walter Max-Moerbeck, Bryan Butler

Telecon Notes

Science topics

Geoff: Time domain (GW counterparts, time-variable imaging, TDEs) and Physics (GC pulsars, plasma physics, stellar/solar work) have good science cases. Two areas where more discussion is needed are synoptic surveys and cosmology projects

Cosmology -- Megamasers, evolution of constants, redshift vs time, large-scale molecular gas surveys. Distinction between "root-N" science and novel capabilities not clear for cosmology? Postpone discussion for now (right people not on telecon).

Synoptic surveys -- is telescope survey-driven or PI-driven? Rachel: mix of both is optimal. Miguel: for decadal survey, needs to involve broad community; large survey data more accessible. Geoff: what future facilities will this interact with (LSST, ALMA, ...)? Rachel: general imaging pipeline needed for broad usability. Steve: not really a "science" issue. Miguel: long baselines, sparse UV much harder to make usable; tension between capability and usability. Geoff: consider SKA precursors (survey mode) vs ALMA (project mode)

What are critical specs for each science product: eg, GC pulsars need BW, freq coverage, sensitivity but not any specific UV coverage

AGN (Walter): LSST probably more interesting for AGN, monitoring variability. Interesting radio work requires VLBI. Geoff: anything interesting at high-sensitivity, mid-resolution? Walter: searches for dual AGN may be interesting. Not clear if this will find large new population.

Gravitational Lenses (Steve): Focus has moved towards sub-mm since radio population has been well investigated. Improved resolution is good. But more interesting for astrophysics than for cosmology.

Geoff: Large-area surveys (eg of molecular lines) could benefit from improved short-baseline versus current VLA. (Miguel?) not just intensity mapping, but imaging generally, eg M31 halos.

Laura: What is goal of telecon, define science or stimulate discussion? Geoff: come up with ~3 high-profile science cases to present at AAS, also stimulate discussion, evetually whitepaper with broader input.

EM counterparts to NS mergers (eg, LIGO) Laura: important future science case. Geoff: what are telescope requirements? Laura: At 5 GHz or 30 GHz transients will vary on shorter timescales, be much easier to associate w/ GW event. multi-freq and wide-field important. Steve: long duration (~days) means survey speed main spec for this. events will be pretty bright, more of a VLA case. Geoff: Should look at Metzger & Berger paper for predictions. What are future (kHz) GW instruments? eLISA may not be looking at right sources.

Laura: survey of stellar-mass BHs in our galaxy. needs wide-area, deep (uJy) survey. Start in galactic bulge, but all-sky also relevant. Flat-spectrum, mainly want sensitivity and resolution to filter out confusing foreground.

Speakers for AAS

Geoff: SOC invited Kawabe (Japan) for international slot. Suggestion of M. Kramer for other speaker to discuss GC pulsars. Other possibilities: Cordes, Kulkarni, Bildsten, Pen, Perran, Nissanke, Nakar, Metzger. Steve: get someone who can cover all the way from neutron stars to MBHs. General agreement that theorist (or maybe optical observer) good idea.

Next steps

Add more details to wiki.

One more telecon pre-Thanksgiving, in about 2 weeks.