REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR
Purpose: Studying the spatial structure of the quasar in the Q2237+0305 gravitational lens system in optical spectral range; estimating the central black hole mass. Design/methodology/approach: The method of reverberation mapping has been used that implies measuring of the time delays between the...
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| Format: | Article |
| Language: | English |
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National Academy of Sciences of Ukraine, Institute of Radio Astronomy
2018-12-01
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| Series: | Radio Physics and Radio Astronomy |
| Subjects: | |
| Online Access: | http://rpra-journal.org.ua/index.php/ra/article/view/1298/pdf |
| _version_ | 1818458621060579328 |
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| author | L. A. Berdina V. S. Tsvetkova V. M. Shulga |
| author_facet | L. A. Berdina V. S. Tsvetkova V. M. Shulga |
| author_sort | L. A. Berdina |
| collection | DOAJ |
| description | Purpose: Studying the spatial structure of the quasar in the Q2237+0305 gravitational lens system in optical spectral range; estimating the central black hole mass.
Design/methodology/approach: The method of reverberation mapping has been used that implies measuring of the time delays between the quasar intrinsic brightness variations in different spectral ranges. We used the macroimage light curves of the Q2237+0305 system in spectral bands V (λeff = 547.7 nm) and R (λeff = 634.9 nm) of Johnson–Cousins photometric system. The reverberation mapping method allows to obtain direct estimates of distances between the quasar regions responsible for radiation in the selected spectral bands.
Findings: The time delay between the V and R light curves is estimated to be 5.58±1.69 days, which is more than an order of magnitude larger than that predicted by a standard thin accretion disk model by Shakura–Sunyaev. As an explanation, a suggestion is made that the standard accretion disk model is not entirely adequate when describing an actual quasar structure.
Conclusions: Such a large time delay means that reverberation responses arise in extended structures located outside the accretion disk. A suggestion that some extended structure capable to efficiently radiate in optical band may exist around the accretion disks has been reported in a number of works dedicated to the microlensing studies and analysis of flux ratio anomalies in gravitationally lensed quasars. Abolmasov and Shakura have shown analytically that a super-Eddington accretion regime may take place for some quasars, which leads to formation of an envelope. The envelope scatters radiation from the disk, thus making the apparent disk size larger. The further development in studying the spatial structure of the Q2237+0305 quasar with the use of reverberation mapping implies involving the data in spectral band I. This will provide two additional spectral bases thus allowing investigation of a wavelength dependence of the corresponding structure dimensions. |
| first_indexed | 2024-12-14T23:01:22Z |
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| institution | Directory Open Access Journal |
| issn | 1027-9636 2415-7007 |
| language | English |
| last_indexed | 2024-12-14T23:01:22Z |
| publishDate | 2018-12-01 |
| publisher | National Academy of Sciences of Ukraine, Institute of Radio Astronomy |
| record_format | Article |
| series | Radio Physics and Radio Astronomy |
| spelling | doaj.art-c6aeab40017a4d5e887ea266aab1da4a2022-12-21T22:44:27ZengNational Academy of Sciences of Ukraine, Institute of Radio AstronomyRadio Physics and Radio Astronomy1027-96362415-70072018-12-0123423524310.15407/rpra23.04.235REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASARL. A. Berdina0V. S. Tsvetkova1V. M. Shulga2Institute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Mystetstv St., Kharkiv, 61002, UkraineInstitute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Mystetstv St., Kharkiv, 61002, Ukraine; Institute of Astronomy of V. N. Karazin Kharkiv National University, 4, Svoboda Sq., Kharkiv, 61022, UkraineInstitute of Radio Astronomy, National Academy of Sciences of Ukraine, 4, Mystetstv St., Kharkiv, 61002, Ukraine; The International Center of Future Science, Jilin University, 2699 Qianjin St., 130012 Changchun, Taiwan, Province of ChinaPurpose: Studying the spatial structure of the quasar in the Q2237+0305 gravitational lens system in optical spectral range; estimating the central black hole mass. Design/methodology/approach: The method of reverberation mapping has been used that implies measuring of the time delays between the quasar intrinsic brightness variations in different spectral ranges. We used the macroimage light curves of the Q2237+0305 system in spectral bands V (λeff = 547.7 nm) and R (λeff = 634.9 nm) of Johnson–Cousins photometric system. The reverberation mapping method allows to obtain direct estimates of distances between the quasar regions responsible for radiation in the selected spectral bands. Findings: The time delay between the V and R light curves is estimated to be 5.58±1.69 days, which is more than an order of magnitude larger than that predicted by a standard thin accretion disk model by Shakura–Sunyaev. As an explanation, a suggestion is made that the standard accretion disk model is not entirely adequate when describing an actual quasar structure. Conclusions: Such a large time delay means that reverberation responses arise in extended structures located outside the accretion disk. A suggestion that some extended structure capable to efficiently radiate in optical band may exist around the accretion disks has been reported in a number of works dedicated to the microlensing studies and analysis of flux ratio anomalies in gravitationally lensed quasars. Abolmasov and Shakura have shown analytically that a super-Eddington accretion regime may take place for some quasars, which leads to formation of an envelope. The envelope scatters radiation from the disk, thus making the apparent disk size larger. The further development in studying the spatial structure of the Q2237+0305 quasar with the use of reverberation mapping implies involving the data in spectral band I. This will provide two additional spectral bases thus allowing investigation of a wavelength dependence of the corresponding structure dimensions.http://rpra-journal.org.ua/index.php/ra/article/view/1298/pdfquasarblack holespatial structureaccretion diskreverberation mapping |
| spellingShingle | L. A. Berdina V. S. Tsvetkova V. M. Shulga REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR Radio Physics and Radio Astronomy quasar black hole spatial structure accretion disk reverberation mapping |
| title | REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR |
| title_full | REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR |
| title_fullStr | REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR |
| title_full_unstemmed | REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR |
| title_short | REVERBERATION RESPONSES IN LIGHT CURVES OF THE Q2237+0305 QUASAR |
| title_sort | reverberation responses in light curves of the q2237 0305 quasar |
| topic | quasar black hole spatial structure accretion disk reverberation mapping |
| url | http://rpra-journal.org.ua/index.php/ra/article/view/1298/pdf |
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