Altai State University has been a member of the international TAIGA scientific collaboration since 2017.

TAIGA (Tunka Advanced Instrument for Cosmic Ray Physics and Gamma-ray Astronomy) is a unique international initiative dedicated to cosmic rays – high-energy particles originating in space. More specifically, scientists operate a dedicated gamma-ray observatory to detect and analyze extensive air showers (radiation invisible to the human eye) produced when cosmic rays interact with the atmosphere. Our partner university, Irkutsk State University, serves as the lead organization for the project.

The TAIGA gamma-ray astronomy observatory is located in Buryatia, in the Tunkinskaya Valley, approximately 50 km from Lake Baikal. The site hosts a hybrid detector complex: an array of instruments that employ different principles and methods to record signals from deep space. Physicists from Altai State University regularly undertake internships at the facility and conduct research (read more here).

In the coming years, the TAIGA collaboration aims to advance to a new level. Plans are underway to identify a site for the construction of a larger-scale TAIGA-100 astronomical complex, which will be an order of magnitude larger than the existing gamma-ray observatory. Site selection is challenging: for observations, optimal conditions require a sufficiently high mountain plain (approximately 2,000 meters above sea level) with minimal cloud cover. Equally important are low aerosol content and anthropogenic light pollution (the site must have a highly transparent atmosphere and be away from large population centers to avoid interference from artificial lighting).

One such option has been proposed by Altai State University scientists—a site in the Chuya Valley of the Altai Republic, within the Kosh-Agach District. It is symbolic that the Tarkhatinsky megalithic complex (the "Altai Stonehenge"), an archaeological monument located in close proximity, is believed by reserachers to be an ancient observatory.

The expedition to the Chuya Steppe began on June 22 and lasted four days. The team included Roman Raikin, Vice-Rector for International Affairs Development at Altai State University and an associate professor in the Department of Radiophysics and Theoretical Physics; Alexander Pakhorukov, a junior researcher at the Research Institute of Applied Physics at Irkutsk State University; Andrey Bondarovich, an associate professor in the Department of Economic Geography and Cartography at Altai State University; and Yegor Mordvin and Artemy Revyakin, researchers at the Altai State University Laboratory of Space Monitoring and Computational Technologies.

In the Chuya Valley, the scientists, together with specialists from the Saylyugemsky National Park, conducted a detailed survey of the site, examined the mechanical properties of the soil for sensor installation, verified cellular network coverage, and collected water samples needed for muon detectors.

Alexander Pakhorukov, a junior researcher at the Applied Physics Research Institute of Irkutsk State University, explains:

At the TAIGA Gamma Observatory, we analyze cosmic radiation and ultra-high-energy gamma quanta. Our new objective is research at even higher energies. Such particles—with gigantic energies—are rarer, and to detect them, we need sites with large detector areas. That is why we've been searching for a new site; it will span 100 square kilometers. We are currently evaluating potential locations for such a mega-detector array. Besides the large area, we also consider the astroclimate – the combination of atmospheric conditions that influence the quality of astronomical observations. In simple terms, we look at how many clear, cloudless nights occur per year. To reach the Chuya Valley, we crossed several mountain passes; the mountains themselves can "hold back" precipitation, making the area beyond them more favorable for observations." Given the satellite monitoring data, the location in the Kosh-Agach District is truly a good one. The next step is to install a weather station there to record the weather and install a temperature streamer – an underground cable buried up to a depth of three meters with temperature sensors arranged in series. Further research is needed before a final decision is made on whether to build a gamma-ray observatory at this location.

Why do astrophysicists study cosmic rays?

Alexander Pakhorukov elaborates:

Cosmic-ray physics is a relatively new science. Research into cosmic radiation has been underway for just over a century. But it's crucial for scientists to understand where such high-energy particles are produced (for example, in supernova explosions) and what mechanisms in space accelerate them—accelerating them to ultra-high energies, fundamentally unattainable in laboratory conditions." In other words, cosmic particles possess energies far exceeding those that we can currently obtain with the most powerful accelerators on Earth. And if we want to investigate cosmic energy, then the only way is to observe cosmic particles.