An international research team involved in the Event Horizon Telescope (EHT) first captured a supermassive black hole in the center of our galaxy and released the image at 22:07 on 12. This is the black hole’s black arc. It was discovered by man after M87, which was first discovered in 2019, as it was called by the Korea Institute of Astronomy and Space Sciences.
Sagittarius: The black hole is located at the center of the Milky Way, about 27,000 light-years from Earth and has a mass about 4 million times the mass of the Sun. Compared to the M87 black hole, its distance from the solar system is close to 1/2000, making it a strong target for black hole research. However, since its mass is 1500 times smaller than that of M87, the gas flow around the black hole changes rapidly and the image suffers from strong scattering, which makes observation difficult compared to M87.
The joint research team has successfully observed black holes using the EHT. EHT is an attempt to take pictures of a black hole by connecting radio telescopes around the world to create a hypothetical Earth-sized telescope. 80 institutions around the world, 300 researchers and 8 radio telescopes have been mobilized for 5 years.
Through the Korea Space Radio Observation Network (KVN) (Yonsei University in Seoul, Ulsan University, and Tamna Radio Observatory in Seogwipo, Jeju), the Astronomical Research Institute confirmed that the structure of the Sagittarius A black hole is close to the circle. With an international research team. This means that the correlation disk created when the surrounding gases are rotated and pulled by the black hole’s gravity has a circular shape, indicating that the black hole is oriented toward Earth.
“The black hole and the M87 black hole have very similar shapes, according to Einstein’s theory of general relativity,” said Sarah Markov, co-chair of the EHT Science Council.
“With this study, we compare and analyze images of the largest supermassive black hole, the M87 black hole, and the smallest arc black hole, and see how gravity works in increasingly very different situations,” said Keichi Asada, PhD, an astrophysics researcher at the Central Taiwan Academy of Sciences. We can test it in more detail.”
“A black hole is the closest black hole among black holes that humans directly observe through collective intelligence,” said Bong-Won Sun, PhD from the Headquarters for Radio Astronomy, who was involved in the study. We are preparing to participate directly in the event.”
◆ The boy who picked up the M87 signal in the mountains… for a whole world
the doctor. Sun was a member of this research team when humans first picked up the signal from a black hole. After receiving his master’s degree in radio astronomy from Yonsei University, he entered the doctoral program at the University of Bonn, Germany, and in 2002 was a postdoctoral researcher at the Max Planck Institute for Radio Astronomy. For reference, Bonn was the center of black hole research at the time.
According to him, there was a boom in black hole research at the time of the laboratory. In addition to traditional observations of jet emission from active galaxies, attempts have been made to capture signals from black holes near the event horizon using high-resolution telescopes. By chance, he joined the research team and took charge of the event horizon monitoring. The signal that has been successfully captured at this point is the starting point for the M87 black hole, which humanity has captured for the first time.
Event horizon: a broad boundary region connecting the interior and exterior of a black hole. When matter goes beyond the event horizon and is sucked into a black hole, some of it is released as energy; So if you use high-resolution monitoring equipment, you can see the edge of the event horizon.
According to the doctor’s opinion. Brown, very long video interferometry (VLBI) observations were recorded at that time. Collecting signals from dark orbs requires very precise timing, which is not suitable for Taperon. A hard disk is required to monitor the event horizon level. At that time, a special hard drive for the radio interferometer was developed, and the research team confirmed the possibility of using the prototype. The result was a huge success, as it was able to pick up the signal from a black hole close to the event horizon.
Very Long Basic Interferometry (VLBI): Multiple radio telescopes located hundreds to thousands of kilometers away simultaneously to observe the same celestial body and implement a virtual huge telescope with an aperture corresponding to the distance between radio telescopes for accuracy (lower resolution). A technique that increases the ability to distinguish between two things.
doctor. Sun said, “At the time, I was the youngest member of the team with a postdoc, so I would climb the mountain with the first prototype and watch it for 12 hours. Not everyone was sure if he would, but the observation went well. It was a record moment in the study of black holes.”
◆ Korea’s performance delayed? “Result of perseverance”
Korea completed KVN in 2008 and began to seriously observe space phenomena. At the time, leading countries such as Japan were also initially skeptical of Korea. This is due to the concern that getting and tuning the signal takes a long time. However, contrary to expectations, KVN produced the same results as Japan’s first observation to verify the telescope’s performance. The correct image appeared when fabricating the confirmed signals.
Since then, KVN has been used for research since 2010. At that time, international event horizon surveys focusing on the United States, Germany and Spain were conducted, and Korea, China and Japan provided observations that could complement M87 and Black Hole. Centered on the Milky Way galaxy as major research topics. Then, in 2017, a campaign was launched in which 8 telescopes in 6 regions could participate at the same time, and Korea was invited to participate. It was the result of a previous search.
Dr. said. Filho, “The telescope has the disadvantage that it is difficult to observe because of the water vapor. But I wasn’t sure, so I couldn’t try. So I tried Korea and got KVN for the first time in the world.”
He added, “KVN can monitor multiple frequencies and create images at the same time. It is a great innovation as the telescope performs multiple functions.”