GBT 4mm Receiver First Light
The National Radio Astronomy Observatory has constructed a dual-beam, dual-polarization receiver for the Green Bank Telescope to cover the low-frequency end of the 3mm atmospheric window from 68--92 GHz. The receiver was recently installed on the GBT to test the functionality of the system. On 2011 May 03, a successful first light spectrum of Orion-KL was obtained (Figure X). Additional development and refinements are planned this summer, with the expectation of commissioning in the fall of 2011 and initial shared-risk science observations in early 2012. See (GBT 4mm Receiver Web Page) for more information.
A spectrum of Orion-KL tuned to the HCN(1-0) triplet at 88.63 GHz observed with the new GBT 4mm receiver. Three short one minute On-Off pairs were taken in daytime under heavy cloud conditions, and no baseline subtraction was done to the data. The CH_3OH transition at 88.59 GHz and the CH_3OCH_3 triplet around 88.71 GHz are also clearly visible. Feel free to contact David Frayer if you have any questions: ().