Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification
We test the impact of gravitational lensing on the lifetime estimates of seven high-redshift quasars at redshift z ≳ 6. The targeted quasars are identified by their small observed proximity zone sizes, which indicate extremely short quasar lifetimes ( t _Q ≲ 10 ^5 yr). However, these estimates of qu...
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/accf20 |
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| author | Minghao Yue Anna-Christina Eilers Robert A. Simcoe Sirio Belli Frederick B. Davies David DePalma Joseph F. Hennawi Charlotte A. Mason Julian B. Muñoz Erica J. Nelson Sandro Tacchella |
| author_facet | Minghao Yue Anna-Christina Eilers Robert A. Simcoe Sirio Belli Frederick B. Davies David DePalma Joseph F. Hennawi Charlotte A. Mason Julian B. Muñoz Erica J. Nelson Sandro Tacchella |
| author_sort | Minghao Yue |
| collection | DOAJ |
| description | We test the impact of gravitational lensing on the lifetime estimates of seven high-redshift quasars at redshift z ≳ 6. The targeted quasars are identified by their small observed proximity zone sizes, which indicate extremely short quasar lifetimes ( t _Q ≲ 10 ^5 yr). However, these estimates of quasar lifetimes rely on the assumption that the observed luminosities of the quasars are intrinsic and not magnified by gravitational lensing, which would bias the lifetime estimates toward younger ages. In order to test the possible effects of gravitational lensing, we obtain high-resolution images of the seven quasars with the Hubble Space Telescope and look for signs of strong lensing. We do not find any evidence of strong lensing, i.e., all quasars are well described by point sources, and no foreground lensing galaxy is detected. We estimate that the strong-lensing probabilities for these quasars are extremely small (∼1.4 × 10 ^−5 ) and show that weak lensing changes the estimated quasar lifetimes by only ≲0.2 dex. We thus confirm that the short lifetimes of these quasars are intrinsic. The existence of young quasars indicates a high obscured fraction, radiatively inefficient accretion, and/or flickering lightcurves for high-redshift quasars. We further discuss the impact of lensing magnification on measurements of black hole masses and Eddington ratios of quasars. |
| first_indexed | 2024-03-12T04:05:46Z |
| format | Article |
| id | doaj.art-90e92c625f7a4f00ae04e2ada6715bca |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:05:46Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-90e92c625f7a4f00ae04e2ada6715bca2023-09-03T11:18:49ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-01950210510.3847/1538-4357/accf20Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing MagnificationMinghao Yue0https://orcid.org/0000-0002-5367-8021Anna-Christina Eilers1https://orcid.org/0000-0003-2895-6218Robert A. Simcoe2https://orcid.org/0000-0003-3769-9559Sirio Belli3https://orcid.org/0000-0002-5615-6018Frederick B. Davies4https://orcid.org/0000-0003-0821-3644David DePalma5Joseph F. Hennawi6https://orcid.org/0000-0002-7054-4332Charlotte A. Mason7https://orcid.org/0000-0002-3407-1785Julian B. Muñoz8https://orcid.org/0000-0002-8984-0465Erica J. Nelson9https://orcid.org/0000-0002-7524-374XSandro Tacchella10https://orcid.org/0000-0002-8224-4505MIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USA ; myue@mit.eduMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USA ; myue@mit.eduMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USA ; myue@mit.eduDipartimento di Fisica e Astronomia, Università di Bologna , Via Gobetti 93/2, I-40129, Bologna, ItalyMax-Planck-Institut für Astronomie , Königstuhl 17, D-69117 Heidelberg, GermanyMIT Kavli Institute for Astrophysics and Space Research , 77 Massachusetts Avenue, Cambridge, MA 02139, USA ; myue@mit.eduDepartment of Physics, University of California , Santa Barbara, CA 93106-9530, USA; Leiden Observatory, Leiden University , Niels Bohrweg 2, NL-2333 CA Leiden, NetherlandsCosmic Dawn Center (DAWN), Denmark; Niels Bohr Institute, University of Copenhagen , Jagtvej 128, DK-2200 København N, DenmarkDepartment of Astronomy, The University of Texas at Austin , 2515 Speedway, Stop C1400, Austin, TX 78712, USA; Center for Astrophysics ∣ Harvard & Smithsonian , Cambridge, MA, USADepartment for Astrophysical and Planetary Science, University of Colorado , Boulder, CO 80309, USADepartment of Physics, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919, Republic of Korea; Kavli Institute for Cosmology, University of Cambridge , Madingley Road, Cambridge, CB3 0HE, UK; Cavendish Laboratory, University of Cambridge , 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UKWe test the impact of gravitational lensing on the lifetime estimates of seven high-redshift quasars at redshift z ≳ 6. The targeted quasars are identified by their small observed proximity zone sizes, which indicate extremely short quasar lifetimes ( t _Q ≲ 10 ^5 yr). However, these estimates of quasar lifetimes rely on the assumption that the observed luminosities of the quasars are intrinsic and not magnified by gravitational lensing, which would bias the lifetime estimates toward younger ages. In order to test the possible effects of gravitational lensing, we obtain high-resolution images of the seven quasars with the Hubble Space Telescope and look for signs of strong lensing. We do not find any evidence of strong lensing, i.e., all quasars are well described by point sources, and no foreground lensing galaxy is detected. We estimate that the strong-lensing probabilities for these quasars are extremely small (∼1.4 × 10 ^−5 ) and show that weak lensing changes the estimated quasar lifetimes by only ≲0.2 dex. We thus confirm that the short lifetimes of these quasars are intrinsic. The existence of young quasars indicates a high obscured fraction, radiatively inefficient accretion, and/or flickering lightcurves for high-redshift quasars. We further discuss the impact of lensing magnification on measurements of black hole masses and Eddington ratios of quasars.https://doi.org/10.3847/1538-4357/accf20QuasarsSupermassive black holes |
| spellingShingle | Minghao Yue Anna-Christina Eilers Robert A. Simcoe Sirio Belli Frederick B. Davies David DePalma Joseph F. Hennawi Charlotte A. Mason Julian B. Muñoz Erica J. Nelson Sandro Tacchella Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification The Astrophysical Journal Quasars Supermassive black holes |
| title | Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification |
| title_full | Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification |
| title_fullStr | Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification |
| title_full_unstemmed | Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification |
| title_short | Detecting and Characterizing Young Quasars. III. The Impact of Gravitational Lensing Magnification |
| title_sort | detecting and characterizing young quasars iii the impact of gravitational lensing magnification |
| topic | Quasars Supermassive black holes |
| url | https://doi.org/10.3847/1538-4357/accf20 |
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