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We present X-ray flux and spectral analyses of the three pointed Suzaku observations of the TeV high synchrotron peak blazar Mrk 421 taken throughout its complete operational duration. The observation taken on 5 May 2008 is, at 364.6 kiloseconds (i.e., 101.3 hours), the longest and most evenly sampled continuous observation of this source, or any blazar, in the X-ray energy 0.8 - 60 keV until now. We found large amplitude intra-day variability in all soft and hard bands in all the light curves. The discrete correction function analysis of the light curves in soft and hard bands peaks on zero lag, showing that the emission in hard and soft bands are cospatial and emitted from the same population of leptons. The hardness ratio plots imply that the source is more variable in the harder bands compared to the softer bands. The source is harder-when-brighter, following the general behavior of high synchrotron peak blazars. Power spectral densities of all three light curves are red noise dominated, with a range of power spectra slopes. If one assumes that the emission originates very close to the central super massive black hole, a crude estimate for its mass, of ~ 4 * 10^{8} M_{odot}, can be made; but if the variability is due to perturbations arising there that are advected into the jet and are thus Doppler boosted, substantially higher masses are consistent with the quickest seen variations. We briefly discuss the possible physical mechanisms most likely responsible for the observed flux and spectral variability.
We present the results of X-ray observations of the well-studied TeV blazar Mrk 421 with the Suzaku satellite in 2006 April 28. During the observation, Mrk 421 was undergoing a large flare and the X-ray flux was variable, decreasing by ~ 50 %, from 7
We present an extensive study of 72 archival Chandra light curves of the high-frequency-peaked type blazar Mrk 421, the first strong extragalactic object to be detected at TeV energies. Between 2000 and 2015 Mrk 421 often displayed intraday variabili
We have examined 13 pointed observations of the TeV emitting high synchrotron peak blazar PKS 2155-304, taken by the Suzaku satellite throughout its operational period. We found that the blazar showed large-amplitude intraday variabilities in the sof
We reviewed X-ray flux and spectral variability properties studied to date by various X-ray satellites for Mrk 421 and PKS 2155-304, which are TeV emitting blazars. Mrk 421 and PKS 2155-304 are the most X-ray luminous blazars in the northern and sout
The archetypical very-high-energy gamma-ray blazar Mrk 421 was monitored for more than 3 years with the Gas Slit Camera onboard Monitor of All Sky X-ray Image (MAXI), and its longterm X-ray variability was investigated. The MAXI lightcurve in the 3 -