ngVLA Community Studies Program (Round 2): Call for Proposals

# ngVLA Community Studies Program (Round 2): Call for Proposals

## Description of the Program

Inspired by dramatic discoveries from the Jansky Very Large Array (VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA), the community has initiated discussion of a future large area radio array optimized for imaging of thermal emission to milli-arcsecond scales that will open new discovery space from proto-planetary disks to distant galaxies. Based on the feedback from the scientific and technical communities at our June 2017 ngVLA meeting in Socorro, consensus was reached for a baseline concept that is documented in ngVLA Memo #17. In summary, the current design consists of 214 18m antennas spread throughout the Southwest U.S. and into northern Mexico delivering: (a) ~10/30x the effective collecting area of the VLA/ALMA at comparable bands; (b) frequency coverage spanning 1.2 -- 116 GHz; (c) interferometric baselines up to 1000 km to achieve milli-arcsecond resolution, with consideration for longer baselines and Very Long Baseline Interferometry; and (d) a dense antenna core on km-scales providing high surface brightness imaging.

Given the success of our first round of ngVLA Community Studies, we are proud to announce a second round aimed at tackling some of the most pressing questions unveiled by the initial studies. ngVLA Community studies provide a mechanism for members of the community to become major contributors to this effort. This second round of studies will be carried out over the next year and be used to help construct a final design concept to be brought to Astro2020. As with the first round, each study will be given an NRAO contact scientist, who will provide the investigators with information they may need to carry out the study, as well as monitor the progress of the investigation.

A successful ngVLA Community Studies project should:

(i) Demonstrate the major scientific/technical advancement being advocated and put it in context for the broader astronomical community.

(ii) State clearly the impact on design choices.

(iii) Ultimately produce a publication in a peer-refereed journal, or at minimum in the ngVLA memo series.

Over the past two and a half years, the U.S. and international astronomy communities have taken a preliminary look at a number of scientific and technical issues that play major roles driving the telescope deign, many of which have been documented in our memo series. The primary objective for this second round of community studies is to further develop the Key Science Goals outlined in Memo #19. Studies and simulations should focus on better quantifying the expected performance of the array for addressing these key science goals and provide additional supporting technical requirements.  Supporting materials for the ngVLA Community Studies, such as notional receiver and array configuration files, can be found on the ngVLA Tools page.

A few examples of study topics that may support these goals include:

• Updated simulations of planet formation using the latest configurations and more realistic phase error considerations.
• Provide quantitative and qualitative feedback on imaging performance of the candidate configurations for a range of imaging cases (e.g., proto-planetary disks, deep fields, large nearby galaxies, etc.) and suggest paths towards improvement.
• An investigation of strategies and requirements for mosaic/on-the-fly large-area mapping science cases.
• A quantitative investigation of options for incorporating large-scale and total power information, and how to best have large dynamic range to spatial scales with good surface brightness sensitivity for realistic science targets (e.g., associated requirements for a short baseline array and the necessity of a single-dish in total power mode).
• A investigation of deep-field imaging and simulations to explore potential dynamic range issues and proper source extraction using the current array configurations.
• An exploration of VLBI imaging and astrometry performance when phasing the ngVLA core with continental scale baselines to better identify supporting technical requirements.

We expect that all accepted Community Studies efforts write up their findings as part of a peer-refereed journal article or ngVLA memo, and present their progress/final results at the "Astronomy Frontiers in the next Decade and Beyond" Science Conference June 26-29, 2018 in Boulder, CO. Consequently, we anticipate to be able to fund most formally accepted proposals at a modest level to offset travel expenses to present results at the June Science Meeting, as well as for page charges from publications expected to result from the study. We additionally expect to fund a small number of these Community Studies at a more significant level (up to \$30,000 per award) through the ngVLA Community Studies Grants (CSGs) program. Proposals requesting financial support beyond \$30,000 must be extremely well justified. Those who expect to require additional funding, please see the Funding Terms and Conditions for the CSGs. Proposals requesting funding will be reviewed  by members of the ngVLA Science Advisory Council

Timeline For Proposal Process:
September 25, 2017 Call for Proposals
October 23, 2017 Proposal Submission Deadline
Early November, 2017 Announce/Fund Accepted Proposals
June 26-29, 2017 Studies to Report Findings at "Astronomy Frontiers in the next Decade and Beyond" Science Meeting
August 2018 Submission of Final Reports (Publication/ngVLA Memo)

## Submission Process

Proposals, consisting of a single PDF, are due via the proposal submission page no later than October 23, 2017.  We expect to approve programs early November, 2017. As stated above, all proposals should detail how their Community Studies program will:

(i) Demonstrate the major scientific/technical advancement being advocated in your study and clearly put its impact in context for the broader astronomical community.

(ii) Describe (as quantitatively as possible) how their findings impact the design choices of the array.

(iii) A brief workplan identifying who will be carrying out most of the study (e.g., students/post-docs).

(iv) A list of expected deliverables to NRAO by the end of the program in Summer 2018, to include a written report that will be submitted to either peer-refereed journal or the ngVLA memo series.

### Basic Studies:

For those not requesting additional funding, we ask that you submit a two-page description of the work that addresses the above mentioned topics. These descriptions will allow the project office to keep track of the multiple threads relating to ngVLA development across the community and coordinate with internal efforts.