Greenland Telescope

Instrumentation

The Greenland Telescope Project aims to deploy a suite of state-of-the-art instruments on the telescope. At first light, single pixel, dual polarization sideband separating heterodyne receivers based on ALMA Band 6 and 7 receivers will be available, along with a room temperature W band receiver for holography and pointing tests on continuum and SiO maser sources, with 350 GHz multibeam and sub-mm and THz heterodyne receivers (including small arrays) planned for deployment in subsequent years. The Project is also seeking partners to develop short and long wavelength bolometer cameras for the 450µm-200µm and 1.3mm-850µm windows, and bolometric spectrometer arrays. The GLT will be able to act as a test bed for novel instruments, including those intended for CCAT.

Estimates of sensitivity for heterodyne observations using state-of-the-art single pixel receivers are given in the table below. Backend spectrometer systems for heterodyne receivers are currently being investigated, but we expect to provide both an ultra-wideband system for single-pixel observations and a narrower bandwidth multi-input system for use with multi-pixel receivers. We expect to operate instruments on a campaign basis, with major instrument reconfigurations taking place during the summer months, when access to the site is easier.

Frequency
(GHz)
Wavelength
(mm)
Receiver Noise
(K)
Transmission System Noise
(K)
Continuum
NEFD
(mJy/beam 1s)
Spectral
NEFD
(mJy/beam 1s, 1km/s)
Spectral
NEFD
(K/beam 1s, 1km/s)
90 3.333 45 0.97 91 33.1 5411.2 0.166
150 2.000 51 0.98 96 35.1 4444.5 0.136
230 1.304 40 0.97 86 31.6 3226.0 0.098
300 1.000 50 0.94 113 42.0 3756.4 0.113
350 0.857 60 0.92 138 51.6 4274.3 0.127
420 0.714 90 0.84 229 87.2 6594.3 0.194
650 0.462 110 0.65 450 182.1 11062.7 0.306
850 0.353 160 0.58 724 316.2 16801.2 0.430
1050 0.286 525 0.16 7798 3748.2 179199.0 4.17
1300 0.231 650 0.16 10659 5942.8 255344.1 5.12
1500 0.200 750 0.15 14711 9448.9 377955.2 6.58

TABLE: Estimated heterodyne single-pixel sensitivities for proposed bands on the GLT, assuming tenth percentile weather at the highest frequency bands, and a 12µm RMS surface. SIS receivers are assumed for bands below 1 THz and HEB receivers for bands above 1 THz.