<i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare
Blazars are known to emit exceptionally variable non-thermal emission over the wide range (from radio to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-12-01
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| Series: | Galaxies |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2075-4434/9/4/118 |
| _version_ | 1797504459552587776 |
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| author | Bhoomika Rajput Ashwani Pandey |
| author_facet | Bhoomika Rajput Ashwani Pandey |
| author_sort | Bhoomika Rajput |
| collection | DOAJ |
| description | Blazars are known to emit exceptionally variable non-thermal emission over the wide range (from radio to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-rays) of electromagnetic spectrum. We present here the results of our <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flux and spectral variability study of the blazar Ton 599, which has been recently observed in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flaring state. Using 0.1–300 GeV <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray data from the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="italic">Fermi</mi></semantics></math></inline-formula> Gamma-ray Space Telescope (hereinafter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="italic">Fermi</mi></semantics></math></inline-formula>), we generated one-day binned light curve of Ton 599 for a period of about one-year from MJD 59,093 to MJD 59,457. During this one year period, the maximum <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flux detected was 2.24 ± 0.25 × <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></semantics></math></inline-formula> ph cm<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> s<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula> at MJD 59,399.50. We identified three different flux states, namely, epoch A (quiescent), epoch B (pre-flare) and epoch C (main-flare). For each epoch, we calculated the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flux variability amplitude (F<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mi>v</mi><mi>a</mi><mi>r</mi></mrow></msub></semantics></math></inline-formula>) and found that the source showed largest flux variations in epoch C with F<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow></mrow><mrow><mi>v</mi><mi>a</mi><mi>r</mi></mrow></msub><mo>∼</mo></mrow></semantics></math></inline-formula> 35%. We modelled the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray spectra for each epoch and found that the Log-parabola model adequately describes the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray spectra for all the three epochs. We estimated the size of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray emitting region as 1.03 × <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mn>16</mn></msup></semantics></math></inline-formula> cm and determined that the origin of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray radiation, during the main-flare, could be outside of the broad line region. |
| first_indexed | 2024-03-10T04:04:52Z |
| format | Article |
| id | doaj.art-fa7dff53a2524930a802fb82b744c5bd |
| institution | Directory Open Access Journal |
| issn | 2075-4434 |
| language | English |
| last_indexed | 2024-03-10T04:04:52Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Galaxies |
| spelling | doaj.art-fa7dff53a2524930a802fb82b744c5bd2023-11-23T08:26:27ZengMDPI AGGalaxies2075-44342021-12-019411810.3390/galaxies9040118<i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 FlareBhoomika Rajput0Ashwani Pandey1Indian Institute of Astrophysics, Block II Koramangala, Bangalore 560034, IndiaIndian Institute of Astrophysics, Block II Koramangala, Bangalore 560034, IndiaBlazars are known to emit exceptionally variable non-thermal emission over the wide range (from radio to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-rays) of electromagnetic spectrum. We present here the results of our <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flux and spectral variability study of the blazar Ton 599, which has been recently observed in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flaring state. Using 0.1–300 GeV <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray data from the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="italic">Fermi</mi></semantics></math></inline-formula> Gamma-ray Space Telescope (hereinafter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="italic">Fermi</mi></semantics></math></inline-formula>), we generated one-day binned light curve of Ton 599 for a period of about one-year from MJD 59,093 to MJD 59,457. During this one year period, the maximum <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flux detected was 2.24 ± 0.25 × <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mrow><mo>−</mo><mn>6</mn></mrow></msup></semantics></math></inline-formula> ph cm<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>2</mn></mrow></msup></semantics></math></inline-formula> s<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></semantics></math></inline-formula> at MJD 59,399.50. We identified three different flux states, namely, epoch A (quiescent), epoch B (pre-flare) and epoch C (main-flare). For each epoch, we calculated the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray flux variability amplitude (F<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mi>v</mi><mi>a</mi><mi>r</mi></mrow></msub></semantics></math></inline-formula>) and found that the source showed largest flux variations in epoch C with F<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow></mrow><mrow><mi>v</mi><mi>a</mi><mi>r</mi></mrow></msub><mo>∼</mo></mrow></semantics></math></inline-formula> 35%. We modelled the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray spectra for each epoch and found that the Log-parabola model adequately describes the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray spectra for all the three epochs. We estimated the size of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray emitting region as 1.03 × <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mn>10</mn><mn>16</mn></msup></semantics></math></inline-formula> cm and determined that the origin of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>γ</mi></semantics></math></inline-formula>-ray radiation, during the main-flare, could be outside of the broad line region.https://www.mdpi.com/2075-4434/9/4/118galaxiesactivegalaxies–quasarsindividual (Ton 599) |
| spellingShingle | Bhoomika Rajput Ashwani Pandey <i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare Galaxies galaxies active galaxies–quasars individual (Ton 599) |
| title | <i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare |
| title_full | <i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare |
| title_fullStr | <i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare |
| title_full_unstemmed | <i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare |
| title_short | <i>γ</i>-ray Flux and Spectral Variability of Blazar Ton 599 during Its 2021 Flare |
| title_sort | i γ i ray flux and spectral variability of blazar ton 599 during its 2021 flare |
| topic | galaxies active galaxies–quasars individual (Ton 599) |
| url | https://www.mdpi.com/2075-4434/9/4/118 |
| work_keys_str_mv | AT bhoomikarajput igirayfluxandspectralvariabilityofblazarton599duringits2021flare AT ashwanipandey igirayfluxandspectralvariabilityofblazarton599duringits2021flare |