The Greenland Telescope

Thomas R. Greve What is the GLT? - A brief history

US proto-type antenna for ALMA Designed and build by VERTEX (2000-2004)

Atacama Large Millimeter/submillimeter Array (ALMA) What is the GLT? - A brief history

US proto-type antenna for ALMA Designed and build by VERTEX (2000-2004)

Awarded to Academia Sinica (TW) and Smithsonian Astrophysical Observatorty (US) by National Science Foundation in 2011 (value 10M$)

Atacama Large Millimeter/submillimeter Array (ALMA) What is the GLT? - Currents partners & budget

• NSF: ~22M$ (local infrastructure)

• SAO: ~10M$ (support buildings)

• ASIAA: ~14M$ (telescope facility) What is the GLT? - Speciﬁcations

• 12m radio telescope, optimised for observations at sub-mm wavelengths

• Cassegrain system with 15 arcminute ﬁeld of view

• Currently located at Thule Airbase →Greenland Summit (~2022).

• Summit: N72.5 W38.5, altitude 3200m. Excellent atmospheric conditions for sub-mm observations What is the GLT? - Speciﬁcations

• 12m radio telescope, optimised for observations at sub-mm wavelengths

• Cassegrain system with 15 arcminute ﬁeld of view

• Currently located at Thule Airbase →Greenland Summit (~2022).

TARGET: SUMMIT STATION• Summit: GREENLAND N72.5 W38.5, altitude 3200m. Excellent atmospheric conditions for !N!72.5,!W!38.5,!al-tude:!3200!m! sub-mm observations What is the GLT? - Observations and current instrumentation

• 2016: Arrival in Thule

• 2017: First light

• 2018: ﬁrst 230GHz fringes between GLT and ALMA

• 2018: 350GHz VLBI testing

• Participating in EHT observations since 2018

First image ever of a black hole - historic discovery! Danish GLT Steering Group www.greenlandtelescope.dk

Current members

• Thomas Greve (DAWN, DTU Space) • Georgios Magdis (DAWN, DTU Space)

• Jes Jørgensen (Starplan, NBI) • Lars Kristensen (Starplan, NBI) • Marianne Vestergaard (Dark, NBI)

• Jørgen Peder Steﬀensen (Ice and Climate, NBI)

National coordination Science/ Logistics Funding Instrumentation National coordination - Activities so far

Year ‘zero’ Sep 2018 • Renewed Danish interest in the GLT, sparked by DTU Space pitch for GLT science sent to IDA (Instrument center for Danish Astrophysics).

Jan 2019 • Talks with Johannes Staguhn (NASA) about bringing the GISMO camera to the GLT

Feb 2019 • DTU-DAWN and NBI-Starplan arranges GLT meeting in Copenhagen with participation of TW and US partners. • Talks with Jørgen Peder Steﬀensen on moving GLT to Greenland Summit • Danish GLT Steering Group is formed • www.greenlandtelescope.dk is launched

Apr 2019 • Press conference at DTU Space on EHT / M87 black hole discovery. Lots of national media attention on the EHT and GLT • Danish Minister of Research requests a personal brieﬁng on black holes the next day at NBI

Aug 2019 • Paul Ho visits DK to discuss Danish involvement (logistics, instrumentation)

Dec 2019 • GLT/GISMO meeting at DAWN-DTU. Everyone is welcome! Science / Instrumentation

Science Instrumentation

• Gas accretion onto black holes, • GISMO 2mm camera active galactic nuclei • Heterodyne high-frequency • Galaxy formation and evolution receivers

• Star formation and interstellar • Instrumentation development and medium pathﬁnder instruments Science / Instrumentation

GISMO installation

• 128 pixel TES bolometer camera optimised for 2mm observations (PI: Staguhn, NASA)

• Proven concept at IRAM 30m telescope

• Some technical challenges ﬁtting GISMO to the GLT but seems solvable

• Technical discussion and planning have begun -- regular telecons

• Will require structural changes to GLT receiver cabin.

• Will require opening up the Nazmyth focus of the GLT Science / Instrumentation

A GLT-GISMO extragalactic survey • Probe the large scale structure of the • Unique opportunity for extragalactic early Universe. Identity the most survey of unprecedented area and massive galaxies ~1Gyr after Big Bang depth • Can be done from Thule prior to • Map North Ecliptic Field (Euclid Dep Summit move Field). Rich ancillary data sets

Galaxies: z=6.5-7.3 7.3-9.0 z=5 DM density simulation (Springer+05) Dec(deg) Logistics - Moving the telescope to summit Skis under the telescope!

• Jørgen Peder Steﬀens (Ice & Climate, NBI) in charge of this.

• 6 skis. Each ski weighs 1.2ton. Dimensions 4.52m × 1.10m.

• Make use of existing US traverse train at Thule for transportation of GLT parts to Summit.

• EGRIP camp will move to Summit for rendevouos with GLT.

• EGRIP: camp while construction GLT and GLT facilities

• EGRIP: provide manpower and machinery for site preparation and GLT assembly.

• Time-frame: 2023-2024 Logistics - Moving the telescope to summit Skis under the telescope!

• Jørgen Peder Steﬀens (Ice & Climate, NBI) in charge of this.

• 6 skis. Each ski weighs 1.2ton. Dimensions 4.52m × 1.10m.

• Make use of existing US traverse train at Thule for transportation of GLT parts to Summit.

• EGRIP camp will move to Summit for rendevouos with GLT.

• EGRIP: camp while construction GLT and GLT facilities

• EGRIP: provide manpower and machinery for site preparation and GLT assembly.

• Time-frame: 2023-2024 Logistics - GLT assembly and camp Summit camp

• EGRIP camp will move to Summit for rendevouos with GLT.

• EGRIP: camp while construction GLT and GLT facilities

• EGRIP: provide manpower and machinery for site preparation and GLT assembly.

• Time-frame: 2023-2024 Funding

Sources

• Danish Center for Instrumentation (Small) • Carlsberg Infrastructure Research Grant (Medium) • Danmarks Frie Forskningsfond (Medium) • Villum Fonden (Medium) • Maersk (Large) • Other Funding

Sources

• Danish Center for Instrumentation (Small) • Carlsberg Infrastructure Research Grant (Medium) • Danmarks Frie Forskningsfond (Medium) • Villum Fonden (Medium) • Maersk (Large) • Other

Pending applications

• Carlsberg Infrastructure Research Grant (1.4MDKK. PI: Greve). To fund transport, installation and commissioning of GISMO onto GLT in Thule. Time-frame: 2020-2022. Funding

Sources

• Danish Center for Instrumentation (Small) • Carlsberg Infrastructure Research Grant (Medium) • Danmarks Frie Forskningsfond (Medium) • Villum Fonden (Medium) • Maersk (Large) • Other

Planned applications

• Maersk (15-20MDKK; NBI-DTU lead). To fund transport, construction of GLT at Summit. How do we ensure DTU Leadership?

Areas

• GLT construction phase (DTU Engineering) • Geodynamics, icesheet (DTU Space, Rene Forsberg) • GLT powered by wind energy (DTU Wind) • Remote sensing, monitoring (DTU Drone Center, Michael Linden Vørnle) • Astronomy research (DTU Space) • Future instrumentation (DTU Space) • Other? The GLT is a great opportunity for Denmark

Scientiﬁc interests Strategic national interests • Major partnership in a sub-mm • Research in the Artic / First telescope would be a game- observatory in the Arctic changer for Danish astronomy. • Geopolitics / national security • Danish participartion in the EHT consortium • Major educational and outreach potential in Denmark and Greenland • Instrumentation development • Strengthening ties between • Other (Ice, geodesy, remote Denmark and Greenland sensing, …)

A permanent astronomical Arctic Major grant observatory in Greenland with (15-20MDKK) Denmark as a major partner. The GLT is a great opportunity for Denmark