The Classification of Blazar Candidates of Uncertain Types
In this work, the support vector machine (SVM) method is adopted to separate BL Lacertae objects (BL Lacs) and flat spectrum radio quasars (FSRQs) in the plots of the photon spectrum index against the photon flux, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" di...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-08-01
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| Series: | Universe |
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| Online Access: | https://www.mdpi.com/2218-1997/8/8/436 |
| _version_ | 1827617504723206144 |
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| author | Jun-Hui Fan Ke-Yin Chen Hu-Bing Xiao Wen-Xin Yang Jing-Chao Liang Guo-Hai Chen Jiang-He Yang Yu-Hai Yuan De-Xiang Wu |
| author_facet | Jun-Hui Fan Ke-Yin Chen Hu-Bing Xiao Wen-Xin Yang Jing-Chao Liang Guo-Hai Chen Jiang-He Yang Yu-Hai Yuan De-Xiang Wu |
| author_sort | Jun-Hui Fan |
| collection | DOAJ |
| description | In this work, the support vector machine (SVM) method is adopted to separate BL Lacertae objects (BL Lacs) and flat spectrum radio quasars (FSRQs) in the plots of the photon spectrum index against the photon flux, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula>, those of the photon spectrum index against the variability index, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi mathvariant="italic">V</mi><mspace width="-0.166667em"></mspace><mi mathvariant="italic">I</mi></mrow></semantics></math></inline-formula> and those of the variability index against the photon flux, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula>. Then, we used the dividing lines to distinguish BL Lacs from FSRQs in the blazar candidates of uncertain types from the <i>Fermi</i>/LAT catalogue. Our main conclusions are: 1. We separate BL Lacs and FSRQs by <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>=</mo><mo>−</mo><mn>0.123</mn><mspace width="0.166667em"></mspace><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi><mo>+</mo><mn>1.170</mn></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula> plot, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>=</mo><mo>−</mo><mn>0.161</mn><mspace width="0.166667em"></mspace><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>+</mo><mn>2.594</mn></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow></mrow></semantics></math></inline-formula> plot and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>=</mo><mn>0.792</mn><mspace width="0.166667em"></mspace><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi><mo>+</mo><mn>9.203</mn></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula> plot. 2. We obtain 932 BL Lac candidates and possible BL Lac candidates, and 585 FSRQ candidates and possible FSRQ candidates. 3. Discussion is given regarding comparisons with the literature. |
| first_indexed | 2024-03-09T09:47:57Z |
| format | Article |
| id | doaj.art-8dc7abb1b7f646558957e62c007d213d |
| institution | Directory Open Access Journal |
| issn | 2218-1997 |
| language | English |
| last_indexed | 2024-03-09T09:47:57Z |
| publishDate | 2022-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj.art-8dc7abb1b7f646558957e62c007d213d2023-12-02T00:24:36ZengMDPI AGUniverse2218-19972022-08-018843610.3390/universe8080436The Classification of Blazar Candidates of Uncertain TypesJun-Hui Fan0Ke-Yin Chen1Hu-Bing Xiao2Wen-Xin Yang3Jing-Chao Liang4Guo-Hai Chen5Jiang-He Yang6Yu-Hai Yuan7De-Xiang Wu8Center for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaDepartment of Physics, School of Physics and Material Science, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaShanghai Key Lab for Astrophysics, Shanghai Normal University, GuiLin Road No. 100, Shanghai 200234, ChinaCenter for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaCenter for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaCenter for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaCenter for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaCenter for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaCenter for Astrophysics, Guangzhou University, WaiHuanXi Road No. 230, Guangzhou 510006, ChinaIn this work, the support vector machine (SVM) method is adopted to separate BL Lacertae objects (BL Lacs) and flat spectrum radio quasars (FSRQs) in the plots of the photon spectrum index against the photon flux, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula>, those of the photon spectrum index against the variability index, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi mathvariant="italic">V</mi><mspace width="-0.166667em"></mspace><mi mathvariant="italic">I</mi></mrow></semantics></math></inline-formula> and those of the variability index against the photon flux, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula>. Then, we used the dividing lines to distinguish BL Lacs from FSRQs in the blazar candidates of uncertain types from the <i>Fermi</i>/LAT catalogue. Our main conclusions are: 1. We separate BL Lacs and FSRQs by <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>=</mo><mo>−</mo><mn>0.123</mn><mspace width="0.166667em"></mspace><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi><mo>+</mo><mn>1.170</mn></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula> plot, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>=</mo><mo>−</mo><mn>0.161</mn><mspace width="0.166667em"></mspace><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>+</mo><mn>2.594</mn></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>α</mi><mi>ph</mi></msub><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow></mrow></semantics></math></inline-formula> plot and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>=</mo><mn>0.792</mn><mspace width="0.166667em"></mspace><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi><mo>+</mo><mn>9.203</mn></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>log</mi><mspace width="0.166667em"></mspace><mrow><mi>V</mi><mspace width="-0.166667em"></mspace><mi>I</mi></mrow><mo>∼</mo><mi>log</mi><mspace width="0.166667em"></mspace><mi>F</mi></mrow></semantics></math></inline-formula> plot. 2. We obtain 932 BL Lac candidates and possible BL Lac candidates, and 585 FSRQ candidates and possible FSRQ candidates. 3. Discussion is given regarding comparisons with the literature.https://www.mdpi.com/2218-1997/8/8/436active galactic nuclei (AGNs)blazarsquasarsBL Lacs |
| spellingShingle | Jun-Hui Fan Ke-Yin Chen Hu-Bing Xiao Wen-Xin Yang Jing-Chao Liang Guo-Hai Chen Jiang-He Yang Yu-Hai Yuan De-Xiang Wu The Classification of Blazar Candidates of Uncertain Types Universe active galactic nuclei (AGNs) blazars quasars BL Lacs |
| title | The Classification of Blazar Candidates of Uncertain Types |
| title_full | The Classification of Blazar Candidates of Uncertain Types |
| title_fullStr | The Classification of Blazar Candidates of Uncertain Types |
| title_full_unstemmed | The Classification of Blazar Candidates of Uncertain Types |
| title_short | The Classification of Blazar Candidates of Uncertain Types |
| title_sort | classification of blazar candidates of uncertain types |
| topic | active galactic nuclei (AGNs) blazars quasars BL Lacs |
| url | https://www.mdpi.com/2218-1997/8/8/436 |
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