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SDSS J141637.44 + 003352.2, a double quasar at a distance for which the light that reaches us was emitted 4.6 billion years ago. The two quasars are 13,000 light-years apart in the sky, and place them near the center of one massive galaxy that is part of a group, as indicated by the adjacent galaxies in the left panel. In the lower panels, optical spectroscopy has broad emission lines publicly connected to each of the two quasars, indicating that the gas is moving at thousands of kilometers per second in the vicinity of two distinct supermassive black holes. The two quasars are different colors, due to different amounts of fabric in front of them. Credit: Silverman et al.
Maunakea observatories discover three pairs of joined supermassive black holes
A cosmic dance between two fusing galaxies, each containing a supermassive black hole that feeds rapidly with so much material that it creates a phenomenon known as a quasar, is a rare find.
Astronomers have discovered several pairs of such fusing galaxies, as luminous “double” quasars, with three Maunakea observatories in Hawaii – Subaru Telescope, WM Keck Observatory and Gemini Observatory. These double quasars are so rare, a research team led by the Kavli Institute of Physics and Mathematics of the Universe at the University of Tokyo estimates only 0.3% of all known quasars have two supermassive black holes located on a collision course with each other,
The study published today in the August 26, 2020 issue of The Astrophysical Journal.
sdss j0847-0013, one of the three, rare double quasars discovered with three observations for maunakea. Credit: Silverman et al
“Despite their rarity, they represent an important stage in the evolution of galaxies, where the central giant awakens, gains mass, and potentially affects the growth of its host system,” said Shenli Tang, a student at the University of Tokyo and co-author of the study.
Quasars are one of the brightest, most energetic objects known in the universe, driven by supermassive black holes that are millions to billions of times more massive than our Sun. When material revolves around a black hole in the center of a galaxy, it is heated to high temperatures, releasing so much light that the quasar can overwhelm its host system. This makes a fusing pair of galaxies with quasar activity difficult to detect; it is difficult to separate the light from the two quasars because they lie in such close proximity to each other. Also, observing a wide enough area of the sky to capture these rare events in sufficient numbers is a challenge.
To overcome these obstacles, the team took advantage of a sensitive broad-based aerial survey using the Hyper Suprime-Cam (HSC) camera on the Subaru Telescope.
“To make our task easier, we started by looking at the 34,476 known quasars of the Sloan Digital Sky Survey with HSC image to identify those that have two (or more) distinct centers,” said lead author John Silverman of the Kavli Institute of Physics. and Mathematics of the Universe. “Honestly, we did not start looking for double quasars. We examined images of these bright quasars to determine in what type of galaxies they preferred when we began to see cases with two optical sources in their centers where we expected only one. ”
The team identified 421 potential cases. However, there was still the chance that many of these were not bona fide double quasars, but rather chance projections such as starlight from our own galaxy. Confirmation requires detailed analysis of the candidates’ light to search for definitive signs of two distinct quasars.
Using Keck Observatory’s Low Resolution Imaging Spectrometer (LRIS) and Gemini Observatory’s Near-Infrared Integral Field Spectrometer, Silverman and his team identified three double quasars, two of which were previously unknown. Each object in the pair showed the signature gas moving at thousands of kilometers per second under the influence of a supermassive black hole.
The newly discovered double quasars demonstrate the promise of wide-area imaging combined with high-resolution spectroscopic observations to open up these elusive objects, which are the key to a better understanding of the growth of galaxies and their supermassive black holes.
Reference: “Dual Supermassive Black Holes at Close Separation Revealed by the Hyper Suprime-Cam Subaru Strategic Program” by John D. Silverman, Shenli Tang, Khee-Gan Lee, Tilman Hartwig, Andy Goulding, Michael A. Strauss, Malte Schramm, Xuheng Ding, Rogemar A. Riffel, Seiji Fujimoto, Chiaki Hikage, Masatoshi Imanishi, Kazushi Iwasawa, Knud Jahnke, Issha Kayo, Nobunari Kashikawa, Toshihiro Kawaguchi, Kotaro Kohno, Wentao Luo, Yoshiki Matsuoka, Ouichi Masuoka, Ouichi Masuoka, Ouichi , Kazuhiro Shimasaku, Hyewon Suh, Nao Suzuki, Yoshiaki Taniguchi, Yoshiki Toba, Yoshihiro Ueda and Naoki Yasuda, 26 August 2020,.
DOI: 10.3847 / 1538-4357 / aba4a3
About LRIS
The Low Resolution Imaging Spectrometer (LRIS) is a very versatile and ultra-sensitive visual and spectrograph visible wavelength built at the California Institute of Technology by a team led by prof. Bev Oke and prof. Judy Cohen and commissioned in 1993. Since then it has seen two major upgrades to further enhance its capabilities: the addition of a second, blue arm optimized for shorter wavelengths of light and the installation of detectors that are much more sensitive to the longest (red) wavelengths. Each arm is optimized for the wavelengths it handles. This wide range of coverage of the wavelength, combined with the high sensitivity of the instrument, allows the study of everything from comets (which have interesting features in the ultraviolet part of the spectrum), to the blue light of star formation, to the red light of very distant objects. LRIS also records the spectra of up to 50 objects simultaneously, particularly useful for studies of clusters of galaxies in the farthest, and earliest, times of the universe. LRIS was used in observing distant supernovae by astronomers who received the 2011 Nobel Prize in Physics for research that accelerated the universe as it expanded.
About WM Keck Observatory
The WM Keck Observatory telescopes are among the most scientifically productive on earth. The two 10-meter optical / infrared telescopes at the top of Maunakea on the island of Hawaii have a suite of advanced instruments including images, multi-object spectrographs, high-resolution spectrographs, integrated field spectrometers, and world-leading laser guide star adaptive optical systems. .
Some of the data presented here were obtained from Keck Observatory, a private 501 (c) 3 non-profit organization operating as a scientific partnership between the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the WM Keck Foundation.
The authors want to acknowledge and acknowledge the very important cultural role and respect that the top of Maunakea has always had in the native Hawaiian community. We are very fortunate to have the opportunity to make observations of this mountain.
