AsianScientist (Mar. 28, 2019) – A team of astronomers in Japan has discovered 83 quasars powered by supermassive black holes (SMBHs) in the early universe. They published their findings in The Astrophysical Journal Letters.
SMBHs are found at the centers of galaxies and have masses millions or even billions of times that of the sun. While they are prevalent in the modern universe, it is unclear when they first formed, and how many of them existed in the early Universe. While researchers cannot observe black holes directly, they can detect them by searching for bright light released when a large quantity of matter falls into a SMBH—a phenomenon known as a quasar.
In this study, a research team led by Associate Professor Yoshiki Matsuoka at Ehime University, Japan, used the Subaru Telescope to look for quasars in the distant universe. The most distant quasar discovered by the team is 13.05 billion light years away, which is tied for the second most distant SMBH ever discovered.
The survey revealed 83 previously-unknown, very distant quasars. The reseachers attributed the bumper crop of SMBH sightings to the fact that earlier studies had been sensitive only to the most luminous quasars, and thus the most massive black holes. They also noted that the average spacing between SMBHs is a billion light years.
“The quasars we discovered will be an interesting subject for further follow-up observations with current and future facilities,” said Matsuoka. “We will also learn about the formation and early evolution of SMBHs, by comparing the measured number density and luminosity distribution with predictions from theoretical models.”
The article can be found at: Matsuoka et al. (2019) Discovery of the First Low-luminosity Quasar at z > 7.
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Source: National Astronomical Observatory of Japan. Photo: National Astronomical Observatory of Japan.
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