TY - JOUR
T1 - Investigating the Accretion Nature of Binary Supermassive Black Hole Candidate SDSS J025214.67-002813.7
AU - Foord, Adi
AU - Liu, Xin
AU - Gültekin, Kayhan
AU - Whitley, Kevin
AU - Shi, Fangzheng
AU - Chen, Yu Ching
N1 - Funding Information:
A.F. acknowledges support by the Porat Postdoctoral Fellowship at Stanford University. X.L. and Y.C.C. acknowledge support by NSF grant AST-2108162 and NASA grant 80NSSC21K0060. Y.C.C. acknowledges support by the government scholarship to study abroad from the ministry of education of Taiwan and the Illinois Survey Science Graduate Student Fellowship. NuSTAR is a project led by the California Institute of Technology (Caltech), managed by the Jet Propulsion Laboratory (JPL), and funded by the National Aeronautics and Space Administration (NASA). We thank the NuSTAR Operations, Software, and Calibrations teams for support with these observations. This research has made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (Caltech, USA). This work is also based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA. This work makes use of data obtained as part of the Karl G. Jansky Very Large Array (VLA), UKIRT Infrared Deep Sky Survey (UKIDSS), Wide-field Infrared Survey (WISE), Sloan Digital Sky Survey (SDSS), and the Galaxy Evolution Explorer (GALEX). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. WISE is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. GALEX is a NASA Small Explorer, launched in 2003 April. We acknowledge NASA's support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the Centre National d’Etudes Spatiales of France and the Korean Ministry of Science and Technology. Some of the data presented in this paper were obtained from the Mikulski Archive for Space Telescopes (MAST) at the Space Telescope Science Institute. The specific observations analyzed can be accessed via doi: 10.17909/t9-bqed-ab26 and doi: 10.17909/t9-p4qg-dd43 . Lastly, this research has made use of NASA's Astrophysics Data System.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/3/1
Y1 - 2022/3/1
N2 - We present results of a multiwavelength analysis of SDSS J025214.67-002813.7, a system that has been previously classified as a binary active galactic nucleus (AGN) candidate based on periodic signals detected in the optical light curves. We use available radio-X-ray observations of the system to investigate the true accretion nature. Analyzing new observations from XMM-Newton and NuSTAR, we characterize the X-ray emission and search for evidence of circumbinary accretion. Although the 0.5-10 keV spectrum shows evidence of an additional soft emission component, possibly due to extended emission from hot nuclear gas, we find the spectral shape is consistent with that of a single AGN. Compiling a full multiwavelength spectral energy distribution (SED), we also search for signs of circumbinary accretion, such as a "notch"in the continuum due to the presence of minidisks. We find that the radio-optical emission agrees with the SED of a standard, radio-quiet, AGN; however, there is a large deficit in emission blueward of ∼1400 Å. Although this deficit in emission can plausibly be attributed to a binary AGN system, we find that the SED of SDSS J0252-0028 is better explained by emission from a reddened, single AGN. However, future studies of the expected hard X-ray emission associated with binary AGNs (especially in the unequal-mass regime) will allow for more rigorous analyses of the binary AGN hypothesis.
AB - We present results of a multiwavelength analysis of SDSS J025214.67-002813.7, a system that has been previously classified as a binary active galactic nucleus (AGN) candidate based on periodic signals detected in the optical light curves. We use available radio-X-ray observations of the system to investigate the true accretion nature. Analyzing new observations from XMM-Newton and NuSTAR, we characterize the X-ray emission and search for evidence of circumbinary accretion. Although the 0.5-10 keV spectrum shows evidence of an additional soft emission component, possibly due to extended emission from hot nuclear gas, we find the spectral shape is consistent with that of a single AGN. Compiling a full multiwavelength spectral energy distribution (SED), we also search for signs of circumbinary accretion, such as a "notch"in the continuum due to the presence of minidisks. We find that the radio-optical emission agrees with the SED of a standard, radio-quiet, AGN; however, there is a large deficit in emission blueward of ∼1400 Å. Although this deficit in emission can plausibly be attributed to a binary AGN system, we find that the SED of SDSS J0252-0028 is better explained by emission from a reddened, single AGN. However, future studies of the expected hard X-ray emission associated with binary AGNs (especially in the unequal-mass regime) will allow for more rigorous analyses of the binary AGN hypothesis.
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U2 - 10.3847/1538-4357/ac4af1
DO - 10.3847/1538-4357/ac4af1
M3 - Article
AN - SCOPUS:85126099572
SN - 0004-637X
VL - 927
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 3
ER -