TY - JOUR
T1 - Dual Supermassive Black Holes at Close Separation Revealed by the Hyper Suprime-Cam Subaru Strategic Program
AU - Silverman, John D.
AU - Tang, Shenli
AU - Lee, Khee Gan
AU - Hartwig, Tilman
AU - Goulding, Andy
AU - Strauss, Michael A.
AU - Schramm, Malte
AU - Ding, Xuheng
AU - Riffel, Rogemar A.
AU - Fujimoto, Seiji
AU - Hikage, Chiaki
AU - Imanishi, Masatoshi
AU - Iwasawa, Kazushi
AU - Jahnke, Knud
AU - Kayo, Issha
AU - Kashikawa, Nobunari
AU - Kawaguchi, Toshihiro
AU - Kohno, Kotaro
AU - Luo, Wentao
AU - Matsuoka, Yoshiki
AU - Matsuda, Yuichi
AU - Nagao, Tohru
AU - Oguri, Masamune
AU - Ono, Yoshiaki
AU - Onoue, Masafusa
AU - Ouchi, Masami
AU - Shimasaku, Kazuhiro
AU - Suh, Hyewon
AU - Suzuki, Nao
AU - Taniguchi, Yoshiaki
AU - Toba, Yoshiki
AU - Ueda, Yoshihiro
AU - Yasuda, Naoki
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved.
PY - 2020/8/20
Y1 - 2020/8/20
N2 - The unique combination of superb spatial resolution, wide-area coverage, and deep depth of the optical imaging from the Hyper Suprime-Cam (HSC) Subaru Strategic Program is utilized to search for dual quasar candidates. Using an automated image analysis routine on 34,476 known Sloan Digital Sky Survey quasars, we identify those with two (or more) distinct optical point sources in HSC images covering 796 deg2. We find 421 candidates out to a redshift of 4.5 of which one hundred or so are more likely after filtering out contaminating stars. Angular separations of 0.″6-4.″0 correspond to projected separations of 3-30 kpc, a range relatively unexplored for population studies of luminous dual quasars. Using Keck I/Low Resolution Imaging Spectrometer and Gemini-N/Near-Infrared Integral Field Spectrometer, we spectroscopically confirm three dual quasar systems at z < 1, two of which are previously unknown out of eight observed, based on the presence of characteristic broad emission lines in each component, while highlighting that the continuum of one object in one of the pairs is reddened. In all cases, the [O iii]λ5007 emission lines have mild velocity offsets, thus the joint [O iii] line profile is not double-peaked. We find a dual quasar fraction of 0.26 ± 0.18% and no evidence for evolution. A comparison with the Horizon-AGN simulation seems to support the case of no evolution in the dual quasar fraction when broadly matching the quasar selection. These results may indicate a scenario in which the frequency of the simultaneous triggering of luminous quasars is not as sensitive as expected to the cosmic evolution of the merger rate or gas content of galaxies.
AB - The unique combination of superb spatial resolution, wide-area coverage, and deep depth of the optical imaging from the Hyper Suprime-Cam (HSC) Subaru Strategic Program is utilized to search for dual quasar candidates. Using an automated image analysis routine on 34,476 known Sloan Digital Sky Survey quasars, we identify those with two (or more) distinct optical point sources in HSC images covering 796 deg2. We find 421 candidates out to a redshift of 4.5 of which one hundred or so are more likely after filtering out contaminating stars. Angular separations of 0.″6-4.″0 correspond to projected separations of 3-30 kpc, a range relatively unexplored for population studies of luminous dual quasars. Using Keck I/Low Resolution Imaging Spectrometer and Gemini-N/Near-Infrared Integral Field Spectrometer, we spectroscopically confirm three dual quasar systems at z < 1, two of which are previously unknown out of eight observed, based on the presence of characteristic broad emission lines in each component, while highlighting that the continuum of one object in one of the pairs is reddened. In all cases, the [O iii]λ5007 emission lines have mild velocity offsets, thus the joint [O iii] line profile is not double-peaked. We find a dual quasar fraction of 0.26 ± 0.18% and no evidence for evolution. A comparison with the Horizon-AGN simulation seems to support the case of no evolution in the dual quasar fraction when broadly matching the quasar selection. These results may indicate a scenario in which the frequency of the simultaneous triggering of luminous quasars is not as sensitive as expected to the cosmic evolution of the merger rate or gas content of galaxies.
UR - http://www.scopus.com/inward/record.url?scp=85090420898&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85090420898&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aba4a3
DO - 10.3847/1538-4357/aba4a3
M3 - Article
AN - SCOPUS:85090420898
SN - 0004-637X
VL - 899
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 154
ER -