4mm Two Pixel Feed

Introduction

NRAO is developing a 4mm dual-beam receiver to cover the low-frequency end of the 3mm atmospheric window from 68-92 GHz. In addition to the wide-range of science enabled, the receiver will allow us to quantify the performance of the GBT at 3mm and refine the pointing-and-control system for the GBT. Spectroscopy is the primary science goal for the instrument, but VLBI observations over at least part of the frequency range will also be supported.

Key Science

Based on the ASTRO-2010 Decadale Survey, four key research areas have been identified for the GBT. The 4mm receiver would greatly enhance the science capabilities in all of these areas.  The complete science case for the receiver is available here

  • Fundamental Physics -- With the VLBA, the GBT 4mm receiver would allow us to probe the fundamental physics near the base of powerful black hole jets in nearby galaxies.
  • The Context of Star Formation -- Molecular spectroscopy of the deuterium species and the other important transitions associated with dense molecular gas with the GBT 4mm receiver would revolutionize studies of the structure and physical properties of cold cloud cores from which stars form.
  • Origin of Life -- The GBT 4mm receiver will carry out molecular spectroscopy of complex organic molecules and pre-biotic molecules in the ISM and comets which are key for studying the conditions from which life eventually forms.
  • Galaxies Across Cosmic Time -- The GBT 4mm receiver would permit the studies of CO(1-0) at intermediate redshifts where the evolution of galaxies is proceeding rapidly and allow for the studies of the dense gas tracers, such as HCN and HCO+, in local star-forming galaxies.

Further Information

Connect with NRAO

The National Radio Astronomy Observatory and Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."

AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.