2001/05/02 by Jun Kataoka, J. Kataoka, Tadayuki Takahashi +14
Engineering · Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Blazar #Computer science #Gamma ray #Jet (fluid) #Jet engine #Link (geometry) #Mechanics #Particle Accelerators and Free-Electron Lasers #Particle physics theoretical and experimental studies #Physics #astro-ph
paper · pdf · doi:10.1086/322442
published as Astrophys.J. 560 (2001) 659 · 46 pages, 8 figures, accepted for publication in the Astrophysical Journal
arxiv created 2001/05/02 · openalex publication_date 2001/10/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We have studied the rapid X-ray variability of three extragalactic TeV γ-ray sources: Mrk 421, Mrk 501, and PKS 2155-304. Analyzing the X-ray light curves obtained from ASCA and/or Rossi X-Ray Timing Explorer observations between 1993 and 1998, we have investigated the variability in the time domain from 10 3 to 10 8 s. For all three sources, both the power spectrum density (PSD) and the structure function (SF) show a rollover with a timescale of the order of 1 day or longer, which may be interpreted as the typical timescale of successive flare events. Although the exact shape of turnover is not well constrained and the low-frequency (long timescale) behavior is still unclear, the high-frequency (short timescale) behavior is clearly resolved. We found that, on timescales shorter than 1 day, there is only small power in the variability, as indicated by a steep power spectrum density of f -2~-3 . This is very different from other types of mass-accreting black hole systems, for which the short-timescale variability is well characterized by a fractal, flickering-noise PSD ( f -1~-2 ). The steep PSD index and the characteristic timescale of flares imply that the X-ray-emitting site in the jet is of limited spatial extent: D ≥ 10 17 cm distant from the base of the jet, which corresponds to ≥10 2 Schwarzschild radii for 10 7-10 M ☉ black hole systems.