Current Status: Commissioning/Shared risk science
Kuntur is an insert that can be installed within the Nāmakanui instrument. It is a sideband-separating (2SB), dual polarization receiver, with a sky frequency of range approximately 609 — 715 GHz (default IF 5.5 GHz; LO tunable frequency range 614 — 710 GHz). It can be used in Stare, Jiggle, and Raster observing modes.
Kuntur, named by collaborators from Brazil and Argentina after the south american bird condor, was developed by the Netherlands Research School for Astronomy (NOVA) laboratory at Groningen, for the Large Latin American Millimeter Array (LLAMA) in Argentina. Kuntur has been integrated at the JCMT for on-sky commissioning and subsequent Very Long Baseline Interferometry (VLBI) observing, a collaboration involving LLAMA, the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA), and the Greenland Telescope (GLT). When installed, the instrument replaces the Āweoweo cartridge in the Nāmakanui receiver. For the cartridge integration, the JCMT staff designed a new cabin optics mirror which was fabricated by the National Astronomical Research Institute of Thailand (NARIT).
Current Status for proposals
Although the instrument is still being commissioned, EAO already has a preliminary sensitivity calculator (integrated into the Hedwig proposal system). Measurements of the main beam and aperture efficiency will be taken throughout the commissioning process, and will be made available to users.
Data Reduction
All Kuntur data are reducible by the Starlink software suite and the output provides a spectra at both LSB and USB. For details on running Kuntur reductions, visit the Heterodyne Data Reduction pages. It is recommended that initially users reduce data from both polarizations separately to check for issues.
Notable Molecular Transitions
| Molecule | Transition | Rest Frequency |
| 13-CO | (6 – 5) | 661.7 GHz |
| CO | (6 – 5) | 691.5 GHz |
| H2O | v2 (1 1 0 1 – 1 0 1 1) | 658.0 GHz |
| HCN | (7 – 6) | 620.3 GHz |
| HCN | (8 – 7) | 708.9 GHz |
Atmospheric Transmission
The 650 GHz atmospheric window (that covers the SCUBA-2 450 µm band) requires much drier conditions than the 230 GHz or 350 GHz windows to be an effective observing band. For a complete view on atmospheric transparency, please refer to the JCMT weather bands.
References
Bintley et al. (2024) Commissioning Kuntur: the LLAMA 690GHz receiver at JCMT, Proc. SPIE 13102, Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy XII, 131021J https://doi.org/10.1117/12.3019709