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ASTRO2020 Preparations

We are preparing a long-term plan for the scientific program of the Green Bank Observatory and the GBT for the period 2020 – 2030. This review of current and future instruments will provide input to the 2020 Decadal survey.

If you have an interest in science at the GBT or GBO please join us in this process. We envision that there will be a few small workshops at various locations during 2018 to develop the science cases and instrumental specifications. You can signal your interest by filling out the form below.


Transformative Science Workshop

The workshop Big Questions. Large Problems, and New Instruments is now over, but the work is continuing. Presentations from the workshop are available on our archived page.

The Argus receiver highlighting the amplifier modules at top and the 4 x 4-pixel card array.

The Argus+ Project at the GBT

The GBT is now into its second winter season with Argus, the 16-pixel camera for spectroscopy in the molecule-rich 3mm atmospheric window between 74 – 116 GHz. Argus is the brainchild of Sarah Church of Stanford University and collaborators, who received an NSF ATI grant to design a modular receiver system for the GBT that could be replicated and expanded in a straightforward way. With the unique combination of angular resolution (6.5 – 9 arcseconds), sensitivity, and field of view of the GBT, Argus is being used for ground-breaking surveys of dense gas in galaxies and nearby star-forming regions. Some recent Argus results will be highlighted at the upcoming winter meeting of the American Astronomical Society in Washington D.C.

Left: Filament in DR21 mapped in 13CO. This map took 40 minutes in only moderate weather (τ=0.4). The footprint of the Argus array is shown upper right. Right: part of OMC-1 mapped by Argus in HNC(1-0). This map took 4.5 hours, including pointing, surface setting and calibration. The white circle shows the Argus beam (figure courtesy of Alvaro Hacar)

The Green Bank Observatory and the original Argus team are now collaborating on the Argus+ project, which would take advantage of the technical development afforded by Argus to produce a camera with ten times the mapping speed. Argus+ will also include a new spectrometer and improvements to the GBT metrology that would double the time available for 3mm spectroscopy each year. Argus+ will routinely produce spectral line maps of key species such as CO, HCN, and HCO+ with a spatial dynamic range (map area / pixel size) of 104 to 105.

As part of the Argus+ project the community will be invited to participate in legacy surveys with the new instrument. There will be a spectroscopic survey of the Gould Belt molecular clouds, and a survey of dense gas tracers in nearby star-forming galaxies. The legacy surveys will produce unique data of lasting value. Argus+ data will also be displayed in exhibits at the GBO Science Center, and will be incorporated into a range of programs in STEM education throughout the region.

The plan for Argus+ has been submitted to the National Science Foundation’s call for pre-proposals to the Major Scientific Instrument Program (MSIP) with Felix J. Lockman (GBO) and Sarah Church (Stanford) as co-PIs. The project will leverage the NSF’s investment in the prototype Argus to produce a uniquely powerful scientific instrument accessible to the U.S. scientific community.

Property Argus Argus+ Notes
Pixels 16 144 Single Pol
IF Bandwidth 1.5 GHz 7 GHz

16 pix x 2 win x 23.4 MHz x 4096 ch
16 pix x 1250 MHz x 1024 ch

144 pix x 600 MHz x 131k ch
16 pix x 1250 MHz x 1024 ch

Receiver Tsys

40 – 80K

30 – 60K

Usable 3mm hours/year



TLS metrology
Frequency Range

74 – 116 GHz

74 – 116 GHz

Map time 6’x6′
dv=0.1 km/sec,
σTb=0.1 K

 53 hours

 5 hours

Includes overhead