upGREAT :

The extension of GREAT into heterodyne arrays for SOFIA

Overview

Fact Sheet

Technology

Science

Consortium

 

The current generation of the GREAT receivers, operating onboard the SOFIA, is using single-pixel heterodyne detectors. Each pixel requires a dedicated cryostat, cooled using liquid Nitrogen and liquid Helium.

 

The upGREAT channels are the second generation receivers for the GREAT project. These new receivers are medium sized arrays, operating closed-cycle coolers. The following Table summarizes the specifications for the upGREAT arrays, compared with the current GREAT channels. The upGREAT LFA is currently scheduled for commis­sioning onboard SOFIA in January 2015. The upGREAT HFA will follow about 1 year later, beginning of 2016.

 

 

Channel

Frequencies (THz)

Lines of Interest

low-frequency L1 a,b

1.25-1.50 (single pixel)

[NII], CO series, OD,HCN,H2D+

low-frequency L2

1.81-1.91 (single pixel)

NH3,OH,CO(16-15),[CII]

mid-frequency M a,b

2.5 – 2.7  (single pixel)

OH(2π3/2),HD

high-frequency H

4.7           (single pixel)

[OI]

upGREAT Low Frequency Array (LFA)

1.9 – 2.5   (14 pixels)

OH lines, [CII],CO series, [OI]

upGREAT High Frequency Array (HFA)

4.7            (7 pixels)

[OI]