{"title":"Relations between the Spectral Indices and Flux Densities of Eight Blazars","authors":"Yu-hai Yuan","doi":"10.1155/2019/8041087","DOIUrl":null,"url":null,"abstract":"<jats:p>Relations between the flux densities (<jats:italic>F</jats:italic>) and spectral indices (<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M1\"><mml:mrow><mml:mi mathvariant=\"normal\">α</mml:mi></mml:mrow></mml:math>) can help us analyze the emission process. In this paper, we choose 8 blazars (0235+164, 0430+052, 1156+295, 3C345, 1308+326, 1413+135, 3C454.3, and 1749+096) from the University of Michigan Radio Observatory (UMRAO) database to study the relations between the spectral indices (<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M2\"><mml:mrow><mml:mi mathvariant=\"normal\">α</mml:mi></mml:mrow></mml:math>) and flux densities at 14.5GHz (<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M3\"><mml:mrow><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant=\"normal\">14.5</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>). The main results are the following. (1) There are strong anticorrelations between <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M4\"><mml:mrow><mml:mi mathvariant=\"normal\">α</mml:mi></mml:mrow></mml:math> and <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M5\"><mml:mrow><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant=\"normal\">14.5</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>, with the correlation coefficient<jats:italic> r</jats:italic> in the range from <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M6\"><mml:mo>-</mml:mo><mml:mn mathvariant=\"normal\">0.33</mml:mn></mml:math> to <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M7\"><mml:mo>-</mml:mo><mml:mn mathvariant=\"normal\">0.87</mml:mn></mml:math>. (2) The <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M8\"><mml:mi mathvariant=\"normal\">α</mml:mi><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant=\"normal\">14.5</mml:mn></mml:mrow></mml:msub></mml:math> distributions show elliptic appearance, which have been fitted by elliptic curves. (3) For most of the sources, the time intervals of <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M9\"><mml:mi mathvariant=\"normal\">α</mml:mi><mml:mo>-</mml:mo><mml:msub><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mn mathvariant=\"normal\">14.5</mml:mn></mml:mrow></mml:msub></mml:math> elliptic circle (<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M10\"><mml:mrow><mml:msub><mml:mrow><mml:mi>T</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:math>) are consistent with the quasi-periodicities calculated by the averaged light curves and spectral variances (<mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" id=\"M11\"><mml:mrow><mml:msub><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant=\"normal\">α</mml:mi><mml:mover accent=\"false\"><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mo>¯</mml:mo></mml:mover></mml:mrow></mml:msub></mml:mrow></mml:math>).</jats:p>","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":" ","pages":""},"PeriodicalIF":1.6000,"publicationDate":"2019-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2019/8041087","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Astronomy","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1155/2019/8041087","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Relations between the flux densities (F) and spectral indices (α) can help us analyze the emission process. In this paper, we choose 8 blazars (0235+164, 0430+052, 1156+295, 3C345, 1308+326, 1413+135, 3C454.3, and 1749+096) from the University of Michigan Radio Observatory (UMRAO) database to study the relations between the spectral indices (α) and flux densities at 14.5GHz (F14.5). The main results are the following. (1) There are strong anticorrelations between α and F14.5, with the correlation coefficient r in the range from -0.33 to -0.87. (2) The α-F14.5 distributions show elliptic appearance, which have been fitted by elliptic curves. (3) For most of the sources, the time intervals of α-F14.5 elliptic circle (Tc) are consistent with the quasi-periodicities calculated by the averaged light curves and spectral variances (PαF¯).
期刊介绍：
Advances in Astronomy publishes articles in all areas of astronomy, astrophysics, and cosmology. The journal accepts both observational and theoretical investigations into celestial objects and the wider universe, as well as the reports of new methods and instrumentation for their study.
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