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Chen YC, Liu X, Foord A, Shen Y, Oguri M, Chen N, Di Matteo T, Holgado M, Hwang HC, Zakamska N. A close quasar pair in a disk-disk galaxy merger at z = 2.17. Nature 2023; 616:45-49. [PMID: 37020007 DOI: 10.1038/s41586-023-05766-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/26/2023] [Indexed: 04/07/2023]
Abstract
Galaxy mergers produce pairs of supermassive black holes (SMBHs), which may be witnessed as dual quasars if both SMBHs are rapidly accreting. The kiloparsec (kpc)-scale separation represents a physical regime sufficiently close for merger-induced effects to be important1 yet wide enough to be directly resolvable with the facilities currently available. Whereas many kpc-scale, dual active galactic nuclei-the low-luminosity counterparts of quasars-have been observed in low-redshift mergers2, no unambiguous dual quasar is known at cosmic noon (z ≈ 2), the peak of global star formation and quasar activity3,4. Here we report multiwavelength observations of Sloan Digital Sky Survey (SDSS) J0749 + 2255 as a kpc-scale, dual-quasar system hosted by a galaxy merger at cosmic noon (z = 2.17). We discover extended host galaxies associated with the much brighter compact quasar nuclei (separated by 0.46″ or 3.8 kpc) and low-surface-brightness tidal features as evidence for galactic interactions. Unlike its low-redshift and low-luminosity counterparts, SDSS J0749 + 2255 is hosted by massive compact disk-dominated galaxies. The apparent lack of stellar bulges and the fact that SDSS J0749 + 2255 already follows the local SMBH mass-host stellar mass relation, suggest that at least some SMBHs may have formed before their host stellar bulges. While still at kpc-scale separations where the host-galaxy gravitational potential dominates, the two SMBHs may evolve into a gravitationally bound binary system in around 0.22 Gyr.
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Affiliation(s)
- Yu-Ching Chen
- Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Xin Liu
- Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
- National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
| | - Adi Foord
- Kavli Institute of Particle Astrophysics and Cosmology, Stanford University, Stanford, CA, USA
| | - Yue Shen
- Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Masamune Oguri
- Center for Frontier Science, Chiba University, Chiba, Japan
- Department of Physics, Graduate School of Science, Chiba University, Chiba, Japan
| | - Nianyi Chen
- McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Tiziana Di Matteo
- McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
- NSF AI Planning Institute for Physics of the Future, Carnegie Mellon University, Pittsburgh, PA, USA
- OzGrav-Melbourne, Australian Research Council Centre of Excellence for Gravitational Wave Discovery, Melbourne, Victoria, Australia
| | - Miguel Holgado
- McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Hsiang-Chih Hwang
- School of Natural Sciences, Institute for Advanced Study, Princeton, NJ, USA
| | - Nadia Zakamska
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD, USA
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Feldman KS, Foord A, Heine HG, Smith IL, Boyd V, Marsh GA, Wood JLN, Cunningham AA, Wang LF. Design and evaluation of consensus PCR assays for henipaviruses. J Virol Methods 2009; 161:52-7. [PMID: 19477200 DOI: 10.1016/j.jviromet.2009.05.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 05/07/2009] [Accepted: 05/18/2009] [Indexed: 10/20/2022]
Abstract
Henipaviruses were first discovered in the 1990s, and their potential threat to public health is of increasing concern with increasing knowledge. Old-world fruit bats are the reservoir hosts for these viruses, and spill-over events cause lethal infections in a wide range of mammalian species, including humans. In anticipation of these spill-over events, and to investigate further the geographical range of these genetically diverse viruses, assays for detection of known and potentially novel strains of henipaviruses are required. The development of multiple consensus PCR assays for the detection of henipaviruses, including both SYBR Green and TaqMan real-time PCRs and a conventional heminested PCR is described. The assays are highly sensitive and have defined specificity. In addition to being useful tools for detection of known and novel henipaviruses, evaluation of assay efficiency and sensitivity across both biological and synthetic templates has provided valuable insight into consensus PCR design and use.
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Affiliation(s)
- K S Feldman
- Institute of Zoology, Zoological Society of London, London, UK.
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