Polarized image of the M87 black hole released last month. Provided by Korea Astronomical Research Institute
An international joint research team participating in 65 organizations around the world, including Korea, revealed the image of a black hole photographed in various wavelength ranges such as infrared, X-ray, and gamma rays.
The research team of the international project’Ecident Horizon Telescope (EHT)’ released an image created by observing the M87 black hole in the center of the Virgo galaxy with various wavelengths such as infrared, X-ray, and gamma rays. Following the polarization image released last month, it contains the overall result, which is expected to play a key role in understanding the phenomena occurring around the M87 black hole.
Supermassive black holes are black holes with masses ranging from tens of thousands to billions of times the mass of the Sun. The M87 black hole is a black hole in the middle of the Virgo Cluster, about 55 million light-years from Earth, and has a mass of 6.5 billion times the mass of the Sun. The EHT research team first observed the M87 black hole with radio telescopes in eight locations around the world in 2017, and in April 2019, it was first published in the international academic journal’Letters of the Journal of Astrophysics’.
On the 24th of last month, the polarized image captured around the M87 black hole was published in the newsletter of the International Journal of Astrophysics. Polarization is an electromagnetic wave that travels in only one direction and is formed when light traveling in all directions is affected by a magnetic field. In other words, it is possible to indirectly confirm the existence of a magnetic field through polarization.
The EHT research team created images by collecting data from about 200 research institutes around the world and about 760 researchers simultaneously observed with radio telescopes and gamma-ray telescopes for about a month from March 2017. The combined operating time of all telescopes used for observation amounts to 300 years.
In terms of the wavelength range, the data includes from a long millimeter (mm) band to a short X-ray and gamma-ray band. The research team analyzed this image to capture the shape of the M87 black hole and accretion disks and jets that are formed in the process of introducing and ejecting high-energy substances. In addition, the results of this analysis revealed that when observed in 2017, the M87 black hole was less active and less material inflow and outflow.
Among the EHT research teams, a total of 10 researchers, including Bong-won Son, senior researcher at Korea Astronomical Research Institute, and Jae-young Cheon, senior researcher, are participating in Korea. This analysis included millimeter-band data of the M87 black hole obtained through the Korea Space Radio Observation Network (KVN) owned by the Korea Astronomical Research Institute.
“Thanks to the KVN performance with the world’s first developed multi-wavelength simultaneous observation system, we were able to provide M87 observation data for a short period of time.” We expect that KVN’s interferometer performance will be further improved with the first radio telescope, and we are confident that it will play a pivotal role in future black hole research.”
“If the polarized image released last month was data that can confirm the existence of a magnetic field, this image can understand various phenomena.” “We will investigate the phenomenon.”
The study was published in the Internet edition of the International Journal of Astrophysics Journal on April 14th. The observation data of the EHT research team can be freely received by anyone in the world through online (https://doi.org/10.25739/mhh2-cw46).
An image of an M87 black hole observed simultaneously with multiple wavelengths. The left row is an image observed in the millimeter band with a high-resolution radio telescope, the middle is an image observed in the nanometer band with an optical telescope, and the right row is an image with the shortest wavelength using X-ray and gamma-ray telescopes. Moon-Yeon Cheon provided data for EVN, VLBA, and EHT video production on the left. Provided by Korea Astronomical Research Institute.