Nearly Periodic Fluctuations in the Long Term X-ray Light Curves of the Blazars AO 0235+164 and 1ES 2321+419

Abstract

We have performed a structure function analysis of the Rossi X-ray Timing Explorer All Sky Monitor data to search for variability in 24 blazars using data trains that each exceed 12 years. Although 20 of them show nominal periods though this technique, the great majority of these `periods' are clearly related to yearly variations arising from the instrument.Nonetheless, an apparently real periodic component of about 17 days was detected for the blazar AO 0235+164 and it was confirmed by discrete correlation function and periodogram analyses. For 1ES 2321+419 a component of variability with a near periodicity of about 420 days was detected by all of these methods. We discuss several possible explanations for these nearly periodic components and conclude that they most likely arise from the intersections of a shock propagating down a relativistic jet that possesses a helical structure.

24 pages, 4 figures, 2 tables

References in corpus (14)

• A massive binary black-hole system in OJ287 and a test of general relativity
• Periodic Oscillations in the Intra-day Optical Light Curves of the Blazar S5 0716+714
• High Frequency VLBI Imaging of the Jet Base of M87
• Optical Intra-day Variability in Blazars
• Statistical analyses of long-term variability of AGN at high radio frequencies
• A Systematic Search for Periodicities in RXTE/ASM Data
• The Intra-Night Optical Variability of the bright BL Lac object S5 0716+714
• Wavelet Analysis of AGN X-Ray Time Series: A QPO in 3C 273?
• Multifrequency variability of the blazar AO 0235+164. The WEBT campaign in 2004-2005 and long-term SED analysis
• Simultaneous X-ray and optical observations of S5 0716+714 after the outburst of March 2004
• VLBI observations of seven BL Lac objects from RGB sample
• Significant Limb-Brightening in the Inner Parsec of Markarian 501
• Multi-color Optical Variability of the TeV Blazar Mrk 501 in the Low-State
• Quasi periodic oscillations in XTE J0111.2--7317, highest frequency among the HMXB pulsars

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