Greenland Telescope Project --- Direct Confirmation of Black Hole with Sub-millimeter VLBI

TL;DR

The Greenland Telescope Project aims to directly image the shadow of the supermassive black hole in M87 using sub-millimeter VLBI, achieving unprecedented resolution with a new telescope in Greenland and global VLBI networks.

Contribution

This work introduces the deployment of the Greenland Telescope as a new VLBI station, enhancing baseline lengths for high-resolution black hole imaging.

Findings

Site conditions are suitable for submm observations, comparable to ALMA.

Simulations support the feasibility of black hole shadow imaging.

The telescope will enable single-dish observations up to 1.5 THz.

Abstract

A 12-m diameter radio telescope will be deployed to the Summit Station in Greenland to provide direct confirmation of a Super Massive Black Hole (SMBH) by observing its shadow image in the active galaxy M87. The telescope (Greenland Telescope: GLT) is to become one of the Very Long Baseline Interferometry (VLBI) stations at sub-millimeter (submm) regime, providing the longest baseline > 9,000 km to achieve an exceptional angular resolution of 20 micro arc sec at 350 GHz, which will enable us to resolve the shadow size of ~40 micro arc sec. The triangle with the longest baselines formed by the GLT, the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, and the Submillimeter Array (SMA) in Hawaii will play a key role for the M87 observations. We have been working on the image simulations based on realistic conditions for a better understanding of the possible observed images. In parallel, retrofitting of the telescope and the site developments are in progress. Based on three years of opacity monitoring at 225 GHz, our measurements indicate that the site is excellent for submm observations, comparable to the ALMA site. The GLT is also expected to make single-dish observations up to 1.5 THz.