The Next Generation Very Large Array (ngVLA) is a development project of the National Radio Astronomy Observatory (NRAO). NRAO is a facility of the National Science Foundation (NSF) operated under cooperative agreement by Associated Universities, Inc. This material is based upon work supported by the NSF under Grant No. AST-1519126. Any opinions, findings, and conclusions or recommendations expressed in the materials are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.