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تسجيل مستخدم جديدتشخيص خصائص الاختلاف البصري الطويل الأجل للبلازار الشديدة في الإشعاع غاما
Characterizing Long-term Optical Variability Properties of $gamma$-ray Bright Blazars
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تأليف
Gopal Bhatta
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تم جمع الملاحظات البصرية لعينة من 12 بلازار باهتة بالإشعاع جاما من أربع مخزونات بيانات بصرية، AAVSO، SMARTS، Catalina و Steward Observatory، لإنشاء منحنيات ضوء مشبعة بشكل كثيف تشمل أكثر من عقد. كجزء من دراسات البلازار عبر الأشعة المتغيرة، تم تنفيذ عدة طرق للتحليل، على سبيل المثال، توزيع الطاقة وعلاقة RMS-flux، على الملاحظات مع هدف مقارنة النتائج مع النتائج المشابهة في النطاق الجاما المعروض في Bhatta & Dhital 2020. وتبين أنه، مثل النطاق الجاما، يظهر البلازار تباينا كبيرا في النطاق البصري الذي يمكن تحديده بتوزيع طاقة معمول بالسجل وعلاقة قوة-قانونية ل RMS على الطاقة. قد يكون هذا علامة على علاقة RMS-flux خطية ذات أصل قابل للاقتراب، لكن التبعات في البيانات لا تسمح لرفض إمكانيات أخرى. عند مقارنة خصائص التباين في الطبقتين، وجد أن البلازار في الجاما تبدو أكثر تباينا مع علاقة RMS-flux خطية أكثر شدة وتوزيع الطاقة الذي يتجاوز إلى الطاقات العالية بشكل أكثر. وأظهرت الدراسة التقاطعية أن باستثناء المصدر 3C 273، فإن الإشعاع البصري والجاما في المصادر تتشابه بشكل كبير، مشيرة إلى وجود موحد للذرات المسؤولة عن الإشعاع البصري والجاما. بالإضافة إلى ذلك، أظهرت المصادر S5 0716+714، Mrk 421، Mrk 501، PKS 1424-418 و PKS 2155-304 دليلا محتملا على وجود تهاويج نظرية متكررة في الإشعاع البصري مع وقت الخصوصية الذي يتساوي بالنسبة لذلك في النطاق الجاما الملحوظ في عملنا السابق.
Optical observations of a sample of 12 $gamma$-ray bright blazars from four optical data archives, AAVSO, SMARTS, Catalina, and Steward Observatory, are compiled to create densely sampled light curves spanning more than a decade. As a part of the blazar multi-wavelength studies, several methods of analyses, e. g., flux distribution and RMS-flux relation, are performed on the observations with an aim to compare the results with the similar ones in the gama-ray band presented in Bhatta & Dhital 2020. It is found that, similar to $gamma$-ray band, blazars display significant variability in the optical band that can be characterized with log-normal flux distribution and a power-law dependence of RMS on flux. It could be an indication of possible inherent linear RMS-flux relation, yet the scatter in the data does not allow to rule out other possibilities. When comparing variability properties in the two bands, the blazars in the gama-rays are found to exhibit stronger variability with steeper possible linear RMS-flux relation and the flux distribution that is more skewed towards higher fluxes. The cross-correlation study shows that except for the source 3C 273, the overall optical and the $gamma$-ray emission in the sources are highly correlated, suggesting a co-spatial existence of the particles responsible for both the optical and $gamma$-ray emission. Moreover, the sources S5 0716+714, Mrk 421, Mrk 501, PKS 1424-418 and PKS 2155-304 revealed possible evidence for quasi-periodic oscillations in the optical emission with the characteristic timescales, which are comparable to those in the $gamma$-ray band detected in our previous work.
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