Oral Presentation

First Submillimeter light at Dome A and its prospects (Remote)

Author(s): Yan Gong (Purple Mountain Observatory)

Presenter: Yan Gong (Purple Mountain Observatory)

Submillimeter (submm) astronomy is vital for probing the cold universe and plays a central role in our modern understanding of the cosmic ecosystem. Yet, ground-based submm observations are severely hampered by atmospheric attenuation, making the identification of exceptionally transparent sites crucial. Dome A, located on the Antarctic Plateau, has been identified as the most promising site on Earth for submm and THz astronomy. Despite this potential, previous attempts at submm observations from Dome A had not been successful. During the 41st Chinese National Antarctic Research Expedition (CHINARE), our team successfully deployed the ATE60 telescope equipped with state-of-the-art SIS receivers. With this new instrument, we conducted the first successful submm commissioning observations at Dome A, targeting two prototypical regions of triggered massive star formation in the CO (4–3) and [C I] 3P_1–3P_0 lines. Together with archival data, these observations provide the first complete view of the carbon cycle in these regions. Notably, we find elevated atomic carbon-to-CO ratios even in high-extinction environments, likely due to deep UV penetration into a highly clumpy interstellar medium. This breakthrough not only demonstrates the feasibility of submillimeter observations at Dome A but also paves the way for future terahertz astronomy. Building on this success, we have launched an ambitious initiative to enable autonomous, self-sustained submm observations and support future interferometric arrays. As a first step, we plan to deploy 1-meter-class THz telescopes capable of simultaneous observations of [C I] and [N II], which will provide unprecedented insights into the structure and evolution of the Galactic ecosystem.