Author(s): , ,
Institution(s): 1. National Radio Astronomy Observatory, 2. Wesleyan University
We discuss the future scientific discovery and technical challenges for cm radio studies, presenting calculations and simulations of the science of a next generation VLA (ngVLA), an array with vastly improved resolution and sensitivity relative to ALMA and JVLA, operating from ~1 GHz to 115 GHz, with an enhanced ability to image thermal objects on milliarcsecond scales, spanning thermal and non-thermal radio astronomy and bridging SKA and ALMA capabilities.
Key areas of astrophysics where ngVLA can make new contributions include:
- Probing deep into dusty protoplanetary disks, revealing terrestrial planet formation on AU-scales — regions that are opaque at shorter wavelengths. Observations in this wavelength range are critically required to study the poorly understood growth of dust into rocks.
- Providing a census and imaging at kpc-scale resolution, of the cool molecular gas in distant galaxies. The ngVLA will be able to observe the lower order molecular transitions in high redshift, normal star forming galaxies, a key diagnostic for understanding the fuel driving the star formation history of the Universe.
- Enabling an unprecedented, wide field imaging capability for nearby galaxies, over the cm frequency range covering key astrochemical tracers, including both thermal/non-thermal radio continuum emission.
- Exploring the otherwise-unobservable deep atmospheres of the giant planets. In addition, the subsurfaces of other solar system bodies (e.g. icy satellites, TNOs, comets, asteroids) can be probed via thermal emission and radar remote sensing.
- Allowing major improvements in synoptic, astrometric and transient/time-domain measurements at cm wavelengths of a wide variety of active sources, including Fast Radio Bursts, AGNs, pulsars and x-ray binaries.
Led by NRAO, work to address the technical challenges for the ngVLA is underway. Areas currently under investigation include: low cost antennas, ultra-wide band feeds and receivers, broad band data transmission, and large N correlators. Minimizing operations costs is also being incorporated into the fundamental design of the array.