---
_id: '17517'
abstract:
- lang: eng
  text: We present an analysis of NuSTAR X-ray observations of three active galactic
    nuclei (AGN) that were identified as candidate subparsec binary supermassive black
    hole (SMBH) systems in the Catalina Real-Time Transient Survey based on apparent
    periodicity in their optical light curves. Simulations predict that close-separation
    accreting SMBH binaries will have different X-ray spectra than single accreting
    SMBHs. We previously observed these AGN with Chandra and found no differences
    between their low-energy X-ray properties and the larger AGN population. However,
    some models predict differences to be more prominent at energies higher than probed
    by Chandra. We find that even at the higher energies probed by NuSTAR, the spectra
    of these AGN are indistinguishable from the larger AGN population. This could
    rule out models predicting large differences in the X-ray spectra in the NuSTAR
    bands. Alternatively, it might mean that these three AGN are not binary SMBHs.
article_number: '104'
article_processing_charge: No
article_type: original
author:
- first_name: M. Lynne
  full_name: Saade, M. Lynne
  last_name: Saade
- first_name: Murray
  full_name: Brightman, Murray
  last_name: Brightman
- first_name: Daniel
  full_name: Stern, Daniel
  last_name: Stern
- first_name: Thomas
  full_name: Connor, Thomas
  last_name: Connor
- first_name: S. G.
  full_name: Djorgovski, S. G.
  last_name: Djorgovski
- first_name: Daniel J.
  full_name: D’Orazio, Daniel J.
  last_name: D’Orazio
- first_name: K. E. S.
  full_name: Ford, K. E. S.
  last_name: Ford
- first_name: Matthew J.
  full_name: Graham, Matthew J.
  last_name: Graham
- first_name: Zoltán
  full_name: Haiman, Zoltán
  id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
  last_name: Haiman
- first_name: Hyunsung D.
  full_name: Jun, Hyunsung D.
  last_name: Jun
- first_name: Elias
  full_name: Kammoun, Elias
  last_name: Kammoun
- first_name: Ralph P.
  full_name: Kraft, Ralph P.
  last_name: Kraft
- first_name: Barry
  full_name: McKernan, Barry
  last_name: McKernan
- first_name: Alexei
  full_name: Vikhlinin, Alexei
  last_name: Vikhlinin
- first_name: Dominic J.
  full_name: Walton, Dominic J.
  last_name: Walton
citation:
  ama: Saade ML, Brightman M, Stern D, et al. NuSTAR observations of candidate subparsec
    binary supermassive black holes. <i>The Astrophysical Journal</i>. 2024;966(1).
    doi:<a href="https://doi.org/10.3847/1538-4357/ad372e">10.3847/1538-4357/ad372e</a>
  apa: Saade, M. L., Brightman, M., Stern, D., Connor, T., Djorgovski, S. G., D’Orazio,
    D. J., … Walton, D. J. (2024). NuSTAR observations of candidate subparsec binary
    supermassive black holes. <i>The Astrophysical Journal</i>. American Astronomical
    Society. <a href="https://doi.org/10.3847/1538-4357/ad372e">https://doi.org/10.3847/1538-4357/ad372e</a>
  chicago: Saade, M. Lynne, Murray Brightman, Daniel Stern, Thomas Connor, S. G. Djorgovski,
    Daniel J. D’Orazio, K. E. S. Ford, et al. “NuSTAR Observations of Candidate Subparsec
    Binary Supermassive Black Holes.” <i>The Astrophysical Journal</i>. American Astronomical
    Society, 2024. <a href="https://doi.org/10.3847/1538-4357/ad372e">https://doi.org/10.3847/1538-4357/ad372e</a>.
  ieee: M. L. Saade <i>et al.</i>, “NuSTAR observations of candidate subparsec binary
    supermassive black holes,” <i>The Astrophysical Journal</i>, vol. 966, no. 1.
    American Astronomical Society, 2024.
  ista: Saade ML, Brightman M, Stern D, Connor T, Djorgovski SG, D’Orazio DJ, Ford
    KES, Graham MJ, Haiman Z, Jun HD, Kammoun E, Kraft RP, McKernan B, Vikhlinin A,
    Walton DJ. 2024. NuSTAR observations of candidate subparsec binary supermassive
    black holes. The Astrophysical Journal. 966(1), 104.
  mla: Saade, M. Lynne, et al. “NuSTAR Observations of Candidate Subparsec Binary
    Supermassive Black Holes.” <i>The Astrophysical Journal</i>, vol. 966, no. 1,
    104, American Astronomical Society, 2024, doi:<a href="https://doi.org/10.3847/1538-4357/ad372e">10.3847/1538-4357/ad372e</a>.
  short: M.L. Saade, M. Brightman, D. Stern, T. Connor, S.G. Djorgovski, D.J. D’Orazio,
    K.E.S. Ford, M.J. Graham, Z. Haiman, H.D. Jun, E. Kammoun, R.P. Kraft, B. McKernan,
    A. Vikhlinin, D.J. Walton, The Astrophysical Journal 966 (2024).
date_created: 2024-09-05T08:57:37Z
date_published: 2024-04-29T00:00:00Z
date_updated: 2024-09-10T14:31:31Z
day: '29'
doi: 10.3847/1538-4357/ad372e
extern: '1'
intvolume: '       966'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
  url: https://doi.org/10.3847/1538-4357/ad372e
month: '04'
oa: 1
oa_version: Published Version
publication: The Astrophysical Journal
publication_identifier:
  issn:
  - 0004-637X
  - 1538-4357
publication_status: published
publisher: American Astronomical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: NuSTAR observations of candidate subparsec binary supermassive black holes
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 966
year: '2024'
...