Greenland Telescope

The project concerns a 12m radio antenna deployed to Pituffik Space Base (Pituffik SB) formerly Thule Air Base (TAB), for Very Long Baseline Interferometry (VLBI) operation at 230 GHz, and to characterize the potential for future high-frequency VLBI work at the Summit Station. Currently, the 12m dish at Pituffik SB operates as part of the Event Horizon Telescope, creating the longest North-South baselines for an interferometric array that is capable of directly observing and imaging the supermassive black hole (SMBH) at the center of galaxy M87. Upgrades to higher frequencies and possible deployment of this or other antennas to the Summit Station would enable higher angular resolution for next-generation black hole studies.

Researchers began assembly at Pituffik SB in 2016 with completion occurring during the winter of 2017. The first measurements were successfully completed in March/April of 2018. The group maintains an intermittent presence in Pituffik performing adjustments and maintenance on the telescope during the summer months, with observations resuming in the winter. In 2018, in coordination with ongoing observations, a film crew from Taiwan visited the base to document the joint effort between the Smithsonian Astrophysical Observatory (SAO) and Academia Sinica Institute of Astronomy and Astrophysics (ASIAA). In July of 2018, a team of five researchers visited Summit Station with the NSF contractor project manager and NSF contractor facility manager as a reconnaissance to assist in future planning with the goal of bringing the telescope to Summit. The group toured current facilities, learned of operations, and visited possible sites for the future telescope location at Summit. In 2019, in addition to annual operation and maintenance activities in Pituffik, a Distinguished Visitor group utilized Air National Guard flights between Pituffik and Kangerlussuaq and then via a day trip to Summit Station and Ilulissat. The group of three set off on a reconnaissance mission for the potential of a large Smithsonian-funded DV trip. In winter 2020 six team members were planned to travel to Pituffik for one-three weeks. Then, due to travel restrictions related to COVID-19, further travel to Pituffik and Summit was canceled. However, remote operations were supported by Vectrus to maintain the equipment. In 2021 operation and maintenance activities continued with onsite support and six researcher visits to Pituffik. In 2022 seven field visits to Pituffik took place throughout the year, with the season starting in late January 2022. In 2023, seven field visits to Pituffik SB took place throughout the year for operation and maintenance activities, with the season starting in March 2023. In 2024, ten field visits to Pituffik SB took place throughout the year for operation and maintenance activities, with the season starting in February 2024. Exploration of a possible ‘pathfinder’ dish to be deployed at Summit Station for VLBI and black hole imaging is underway.

In 2025 the Greenland Telescope will be involved in VLBI observations with the Event Horizon Telescope (EHT) in April, for imaging Black hole sources, and studying the time variation of emission immediately around the black hole and jet in M87 and other sources. In both April and September, the team will conduct VLBI observing campaigns with the Global Millimeter VLBI Array (a network of about 20 telescopes around the world), at the frequency of 86 GHz. Associated with these two VLBI runs, are a range of technical activities including various commissioning and engineering tasks at the antenna to ensure that all the instrumentation components are operating to their specifications, to guarantee the highest quality data for our science objectives. Approximately 10 field visits to Pituffik SB are planned throughout the year for operation and maintenance activities, with the season starting in March 2025.

Battelle ARO will provide project management support, AMC cargo shipment and freight handling, heated storage space, NSF truck and fuel, field safety training, and lodging. The NSF will recoup costs associated with this support directly from SAO and/or ASIAA. Battelle ARO project management support will include arrangements for Pituffik SB base clearances and AMC ticketing; however, all services will be paid for directly by the research team. All other logistics will be arranged and paid for by the PI/project.

Battelle ARO will provide project management support, AMC cargo shipment and freight handling, heated storage space, NSF truck and fuel and lodging. The NSF will recoup costs associated with this support directly from SAO and/or ASIAA. Battelle ARO project management support will include arrangements for Pituffik SB base clearances and AMC ticketing; however, all services will be paid for directly by the research team. All other logistics will be arranged and paid for by the PI/project.