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Large Submillimeter Telescope

Credit: TNG Simulations


About LST


We are planning to construct the world's largest (50 m diameter) millimeter and submillimeter-wave telescope in Chile, capable of observing a wide field and broad wavelength range simultaneously. To receive electromagnetic waves shorter than millimeters, we are conducting research to accurately predict deformations of the large antenna caused by gravity and wind and to achieve a wide field of view. By leveraging dramatic advancements in superconducting detection technology, we will maximize the extraction of astronomical information from the received electromagnetic waves. At the LST, we aim to revolutionize the concept of observatories by integrating the explosive progress in data science, and creating a research platform. Our goal is to unravel the birth of the "first galaxies" and elucidate the lineage from there to the diverse universe we see today.

Credit: MELCO


Millimeter and submillimeter waves refer to electromagnetic waves with wavelengths between radio waves and infrared. Earth's atmosphere is not always transparent in this wavelength band due to the presence of water vapor. The LST will be constructed in one of the driest regions on Earth, the Atacama Plateau in Chile, at an altitude of 5000 meters. Here, the ALMA (Atacama Large Millimeter/submillimeter Array) telescope, which consists of 64 antennas, is already in operation through large-scale international cooperation. ALMA and LST will mutually enhance each other in every aspect. However, realizing and operating the LST will involve overcoming numerous challenges, such as power supply and the transfer of massive amounts of observational data. We will build an observatory that considers the global environment, respects the history and culture of the local Chilean community, and harmonizes with Chile's future vision.


The strength of the LST lies not only in its status as the largest telescope in the history of millimeter and submillimeter wave astronomy. The LST will develop and equip instruments capable of observing a field of view wider than four full moons and a frequency range exceeding 100 GHz simultaneously. This will boost the capability of celestial exploration by nearly four orders of magnitude, representing a revolutionary enhancement. We are also advancing the development of devices that measure the orientation of electromagnetic waves from celestial bodies, thereby revealing the magnetic fields of these objects. Additionally, to make discoveries from astronomically large quantities of big data, we will mobilize knowledge from data science and artificial intelligence technologies to support astronomers. The overwhelming sensitivity will enable the detection of celestial objects in a short time, producing movies of these objects. This marks the true emergence of time-domain astronomy in the millimeter and submillimeter wavebands, where phenomena unknown to humanity await discovery.



The overwhelming exploration capability of the "invisible universe"

In the millimeter and submillimeter wavebands, the realization of a 50m single-dish telescope capable of simultaneously observing a wide field of view greater than one degree and a frequency range exceeding 100 GHz signifies the development of a complementary discovery space to ALMA. We will link dramatic technological advancements in superconducting detectors to the development of large-scale ultra-wideband spectroscopic imaging instruments. This will enable unprecedented wide-area 3D exploration in the search for millimeter and submillimeter waveband emission line galaxies. Additionally, compared to existing millimeter and submillimeter imaging devices, we will employ a wide-area imaging camera with more than four orders of magnitude higher exploration capabilities, thereby fully pioneering time-domain astronomy. Armed with the overwhelming exploration capabilities of the LST, we will pursue not only the "known unknowns" but also the "unknown unknowns."

Credit: Herschel Space Observatory


The Science Aimed for by the LST

There are still numerous unresolved issues in astronomy, and the LST will tackle these based on the free ideas of individual researchers. The LST will address three particularly important and fundamental questions: (1) How were the first stars in the universe born, and how were the first galaxies formed? (2) During the early period of the universe's history, from the Big Bang to reionization, how did galaxies come to possess supermassive black holes? (3) The stars and planetary systems observed in the present-day universe exhibit diverse properties but also share common characteristics. What are the physical laws governing the seemingly contradictory nature of diversity and universality? Beyond these three questions, together with the LST, we will discover unknown natural phenomena and take on the challenge of elucidating them.



Towards Achieving the World's Best Submillimeter Astronomy

We are proceeding with the LST project with a strong focus on synergistic effects with ALMA. The mission assigned to the LST includes wide-area sky surveys, spectroscopic exploration, and polarization observations. There are technical challenges that must be overcome to achieve these ambitious specifications. For example, (1) how can we realize and maintain a 50m large-aperture telescope capable of observing in the submillimeter/terahertz wavebands in an environment without a dome? (2) How can we realize a 1-megapixel superconducting detector array that can fully utilize a wide field of view of one square degree or more? (3) How can we achieve highly precise polarization observations? (4) How can we efficiently process the extremely large amount of data produced by the LST and extract information from celestial objects by incorporating data science and statistical methods? (5) How can we store data in a manner that allows for reanalysis and verification, ensuring its preservation and transmission to future generations, with future research progress in mind? We are tackling these challenges in cooperation with research institutions worldwide, including the European 50m submillimeter telescope project, AtLAST.





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