How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry?
The (sub)millimeter wavelengths (86–690 GHz) very long baseline interferometry will provide ∼5–40 μ as angular resolution, ∼10 mJy baseline sensitivity, and ∼1 μ as yr ^−1 proper-motion precision, which can directly detect supermassive black hole binary (SMBHB) systems by imaging the two visible sou...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/ad0da1 |
| _version_ | 1797357522063982592 |
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| author | Shan-Shan Zhao Wu Jiang Ru-Sen Lu Lei Huang Zhiqiang Shen |
| author_facet | Shan-Shan Zhao Wu Jiang Ru-Sen Lu Lei Huang Zhiqiang Shen |
| author_sort | Shan-Shan Zhao |
| collection | DOAJ |
| description | The (sub)millimeter wavelengths (86–690 GHz) very long baseline interferometry will provide ∼5–40 μ as angular resolution, ∼10 mJy baseline sensitivity, and ∼1 μ as yr ^−1 proper-motion precision, which can directly detect supermassive black hole binary (SMBHB) systems by imaging the two visible sources and tracking their relative motions. Such a way exhibits an advantage compared to indirect detect methods of observing periodic signals in motion and light curves, which are difficult to confirm from competing models. Moreover, tracking relative motion at (sub)millimeter wavelengths is more reliable, as there is a negligible offset between the emission region and the black hole center. In this way, it is unnecessary to correct the black hole location by a prior of jet morphology as it would be required at longer wavelengths. We extend the formalism developed in D’Orazio & Loeb (2018) to link the observations with the orbital evolution of SMBHBs from the ≲10 kpc dynamical friction stages to the ≲0.01 pc gravitational radiation stages, and estimate the detectable numbers of SMBHBs. By assuming 5% of active galactic nuclei holding SMBHBs, we find that the number of detectable SMBHBs with redshift z ≤ 0.5 and mass M ≤ 10 ^11 M _⊙ is about 20. Such a detection relies heavily on proper-motion precision and sensitivity. Furthermore, we propose that the simultaneous multifrequency technique plays a key role in meeting the observational requirements. |
| first_indexed | 2024-03-08T14:46:22Z |
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| id | doaj.art-d238118dfc7f4a3db1959c593cd2703b |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-08T14:46:22Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
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| spelling | doaj.art-d238118dfc7f4a3db1959c593cd2703b2024-01-11T09:50:27ZengIOP PublishingThe Astrophysical Journal1538-43572024-01-0196112010.3847/1538-4357/ad0da1How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry?Shan-Shan Zhao0https://orcid.org/0000-0002-9774-3606Wu Jiang1https://orcid.org/0000-0001-7369-3539Ru-Sen Lu2https://orcid.org/0000-0002-7692-7967Lei Huang3https://orcid.org/0000-0002-1923-227XZhiqiang Shen4https://orcid.org/0000-0003-3540-8746Shanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People's Republic of China ; zhaoss@shao.ac.cnShanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People's Republic of China ; zhaoss@shao.ac.cn; Key Laboratory of Radio Astronomy and Technology, Chinese Academy of Sciences , A20 Datun Road, Chaoyang District, Beijing 100101, People's Republic of ChinaShanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People's Republic of China ; zhaoss@shao.ac.cn; Key Laboratory of Radio Astronomy and Technology, Chinese Academy of Sciences , A20 Datun Road, Chaoyang District, Beijing 100101, People's Republic of China; Max-Planck-Institut für Radioastronomie , Auf dem Hügel 69, D-53121 Bonn, GermanyShanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People's Republic of China ; zhaoss@shao.ac.cnShanghai Astronomical Observatory, Chinese Academy of Sciences , 80 Nandan Road, Shanghai 200030, People's Republic of China ; zhaoss@shao.ac.cn; Key Laboratory of Radio Astronomy and Technology, Chinese Academy of Sciences , A20 Datun Road, Chaoyang District, Beijing 100101, People's Republic of ChinaThe (sub)millimeter wavelengths (86–690 GHz) very long baseline interferometry will provide ∼5–40 μ as angular resolution, ∼10 mJy baseline sensitivity, and ∼1 μ as yr ^−1 proper-motion precision, which can directly detect supermassive black hole binary (SMBHB) systems by imaging the two visible sources and tracking their relative motions. Such a way exhibits an advantage compared to indirect detect methods of observing periodic signals in motion and light curves, which are difficult to confirm from competing models. Moreover, tracking relative motion at (sub)millimeter wavelengths is more reliable, as there is a negligible offset between the emission region and the black hole center. In this way, it is unnecessary to correct the black hole location by a prior of jet morphology as it would be required at longer wavelengths. We extend the formalism developed in D’Orazio & Loeb (2018) to link the observations with the orbital evolution of SMBHBs from the ≲10 kpc dynamical friction stages to the ≲0.01 pc gravitational radiation stages, and estimate the detectable numbers of SMBHBs. By assuming 5% of active galactic nuclei holding SMBHBs, we find that the number of detectable SMBHBs with redshift z ≤ 0.5 and mass M ≤ 10 ^11 M _⊙ is about 20. Such a detection relies heavily on proper-motion precision and sensitivity. Furthermore, we propose that the simultaneous multifrequency technique plays a key role in meeting the observational requirements.https://doi.org/10.3847/1538-4357/ad0da1Supermassive black holesActive galactic nucleiSubmillimeter astronomyVery long baseline interferometryProper motions |
| spellingShingle | Shan-Shan Zhao Wu Jiang Ru-Sen Lu Lei Huang Zhiqiang Shen How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry? The Astrophysical Journal Supermassive black holes Active galactic nuclei Submillimeter astronomy Very long baseline interferometry Proper motions |
| title | How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry? |
| title_full | How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry? |
| title_fullStr | How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry? |
| title_full_unstemmed | How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry? |
| title_short | How Many Supermassive Black Hole Binaries Are Detectable through Tracking Relative Motions by (Sub)millimeter Very Long Baseline Interferometry? |
| title_sort | how many supermassive black hole binaries are detectable through tracking relative motions by sub millimeter very long baseline interferometry |
| topic | Supermassive black holes Active galactic nuclei Submillimeter astronomy Very long baseline interferometry Proper motions |
| url | https://doi.org/10.3847/1538-4357/ad0da1 |
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