  The next generation Very Large Array (ngVLA) is a transformational radio
observatory being designed by the U.S. National Radio Astronomy Observatory
(NRAO). It will provide order of magnitude improvements in sensitivity,
resolution, and uv coverage over the current Jansky Very Large Array (VLA) at
~1.2-50 GHz and extend the frequency range up to 70-115 GHz. This document is a
white paper written by members of the Canadian community for the 2020 Long
Range Plan panel, which will be making recommendations on Canada's future
directions in astronomy. Since Canadians have been historically major users of
the VLA and have been valued partners with NRAO for ALMA, Canada's
participation in ngVLA is welcome. Canadians have been actually involved in
ngVLA discussions for the past five years, and have played leadership roles in
the ngVLA Science and Technical Advisory Councils. Canadian technologies are
also very attractive for the ngVLA, in particular our designs for radio
antennas, receivers, correlates, and data archives, and our industrial
capacities to realize them. Indeed, the Canadian designs for the ngVLA antennas
and correlator/beamformer are presently the baseline models for the project.
Given the size of Canada's radio community and earlier use of the VLA (and
ALMA), we recommend Canadian participation in the ngVLA at the 7% level. Such
participation would be significant enough to allow Canadian leadership in
gVLA's construction and usage. Canada's participation in ngVLA should not
preclude its participation in SKA; access to both facilities is necessary to
meet Canada's radio astronomy needs. Indeed, ngVLA will fill the gap between
those radio frequencies observable with the SKA and ALMA at high sensitivities
and resolutions. Canada's partnership in ngVLA will give it access to
cutting-edge facilities together covering approximately three orders of
magnitude in frequency.
