The dual nature of blazar fast variability

• Verfasst von: Raiteri, Claudia Maria [VerfasserIn]
• Verfasst von: Kurtanidze, Sofia O. [VerfasserIn]
• Verfasst von: Kurtanidze, Omar M. [VerfasserIn]
• Verfasst von: Nikolashvili, Maria G. [VerfasserIn]
• Titel: The dual nature of blazar fast variability
• Titelzusatz: space and ground observations of S5 0716+714
• Verf.angabe: CM Raiteri, M Villata, D Carosati, E Benítez, SO Kurtanidze, AC Gupta, DO Mirzaqulov, F D’Ammando, VM Larionov, T Pursimo, JA Acosta-Pulido, GV Baida, B Balmaverde, G Bonnoli, GA Borman, MI Carnerero, W-P Chen, V Dhiman, A Di Maggio, SA Ehgamberdiev, D Hiriart, GN Kimeridze, OM Kurtanidze, CS Lin, JM Lopez, A Marchini, K Matsumoto, R Mujica, M Nakamura, AA Nikiforova, MG Nikolashvili, DN Okhmat, J Otero-Santos, N Rizzi, T Sakamoto, E Semkov, LA Sigua, L Stiaccini, IS Troitsky, AL Tsai, AA Vasilyev and AV Zhovtan
• Jahr: 2021
• Jahr des Originals: 2020
• Umfang: 16 S.
• Fussnoten: Published: 17 November 2020 ; Gesehen am 10.03.2021
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2021
• Band/Heft Quelle: 501(2021), 1 vom: Feb., Seite 1100-1115
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/staa3561
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1751047008

Abstract

Blazar S5 0716+714 is well-known for its short-term variability, down to intraday time-scales. We here present the 2-min cadence optical light curve obtained by the TESS space telescope in 2019 December-2020 January and analyse the object fast variability with unprecedented sampling. Supporting observations by the Whole Earth Blazar Telescope Collaboration in B, V, R, and I bands allow us to investigate the spectral variability during the TESS pointing. The spectral analysis is further extended in frequency to the UV and X-ray bands with data from the Neil Gehrels Swift Observatory. We develop a new method to unveil the shortest optical variability time-scales. This is based on progressive de-trending of the TESS light curve by means of cubic spline interpolations through the binned fluxes, with decreasing time bins. The de-trended light curves are then analysed with classical tools for time-series analysis (periodogram, autocorrelation, and structure functions). The results show that below 3 d there are significant characteristic variability time-scales of about 1.7, 0.5, and 0.2 d. Variability on time-scales $\lesssim 0.2$ d is strongly chromatic and must be ascribed to intrinsic energetic processes involving emitting regions, likely jet substructures, with dimension less than about 10−3 pc. In contrast, flux changes on time-scales $\gtrsim 0.5$ d are quasi-achromatic and are probably due to Doppler factor changes of geometric origin.