TY - JOUR
T1 - A close quasar pair in a disk–disk galaxy merger at z = 2.17
AU - Chen, Yu-ching
AU - Liu, Xin
AU - Foord, Adi
AU - Shen, Yue
AU - Oguri, Masamune
AU - Chen, Nianyi
AU - Di Matteo, Tiziana
AU - Holgado, Miguel
AU - Hwang, Hsiang-chih
AU - Zakamska, Nadia
N1 - Funding Information:
We thank A. Kemball and A. Gross for helpful discussions on strong lensing. We thank M. Leveille, A. Vick, R. Campbell, R. McGurk, J. Cortes, T. R. Geballe, S. Leggett, A. Nitta, T. Seccull and H. Medlin for their help with our HST, Keck, Gemini and VLA observations. Y.-C.C. thanks J. Li and H. Guo for their help with the GALFIT and PyQSOFit codes. M.O. acknowledges support from JSPS KAKENHI grant nos. JP20H00181, JP20H05856 and JP22H01260. This work is supported by the Heising-Simons Foundation and Research Corporation for Science Advancement and National Science Foundation (NSF) grant nos. AST-2108162 and AST-2206499. This research was supported in part by the NSF under no. PHY-1748958. Support for programme no. 23700237 was provided by NASA through Chandra Award no. GO2-23099X issued by the Chandra X-ray Observatory Center, which is operated by the Smithsonian Astrophysical Observatory for and on behalf of NASA under contract no. NAS 8-03060. Support for programme nos. HST-GO-15900 (principal investigator (PI): H. Hwang), HST-GO-16210 and HST-GO-16892 was provided by NASA through grants from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Incorporated, under NASA contract no. NAS5-26555. The National Radio Astronomy Observatory is a facility of the NSF operated under cooperative agreement by Associated Universities, Inc. Based in part on data obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among 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 W. M. Keck Foundation. This research has made use of the Keck Observatory Archive, which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute, under contract with the National Aeronautics and Space Administration. We wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Based in part on observations obtained at the international Gemini Observatory (programme nos. 2020B-FT-113 and GN-2022A-Q-139; PI: X. Liu), a programme of NSF’s NOIRLab, which is managed by the Association of Universities for Research in Astronomy under a cooperative agreement with the NSF on behalf of the Gemini Observatory partnership: the NSF (USA), National Research Council (Canada), Agencia Nacional de Investigación y Desarrollo (Chile), Ministerio de Ciencia, Tecnología e Innovación (Argentina), Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brazil) and Korea Astronomy and Space Science Institute (Republic of Korea). This work was enabled by observations made from the Gemini North telescope, located within the Maunakea Science Reserve and adjacent to the summit of Maunakea. We are grateful for the privilege of observing the Universe from a place that is unique in both its astronomical quality and cultural significance. This work makes use of SDSS-I/II and SDSS-III/IV data ( http://www.sdss.org/ and http://www.sdss3.org/ , respectively).
Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2023/4/6
Y1 - 2023/4/6
N2 - 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.
AB - 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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U2 - 10.1038/s41586-023-05766-6
DO - 10.1038/s41586-023-05766-6
M3 - Article
C2 - 37020007
SN - 0028-0836
VL - 616
SP - 45
EP - 49
JO - Nature
JF - Nature
IS - 7955
ER -