X-ray Emission of Mkn 421: New Clues From Its Spectral Evolution. I. Temporal Analysis

Abstract

Mkn 421 was repeatedly observed with BeppoSAX in 1997-1998. This is the first of two papers where we present the results of a thorough temporal and spectral analysis of all the data available to us, focusing in particular on the flare of April 1998, which was simultaneously observed also at TeV energies. Here we focus on the time analysis, while the spectral analysis and physical interpretation are presented in the companion paper. The detailed study of the flare in different energy bands reveals very important new results: i) hard photons lag the soft ones by 2-3 ks -a behavior opposite to what is normally found in high energy peak BL Lacs X-ray spectra; ii) the flare light curve is symmetric in the softest X-ray band, while it becomes increasingly asymmetric at higher energies, with the decay being progressively slower than the rise; iii) the flux decay of the flare can be intrinsically achromatic if a stationary underlying emission component is present. The temporal and spectral information obtained challenge the simplest models currently adopted for the (synchrotron) emission and most importantly provide clues on the particle acceleration process.

arXiv commentAccepted for publication in The Astrophysical Journal. 13 pages, LaTeX using emulateapj, onecolfloat and apsfonts, 14 PostScript figures, 5 Tables

References in corpus (13)

• Unified Schemes for Radio-Loud Active Galactic Nuclei
• A Unifying View of the Spectral Energy Distributions of Blazars
• A theoretical unifying scheme for gamma-ray bright blazars
• On Uncertainties in Cross-Correlation Lags and the Reality of Wavelength-Dependent Continuum Lags in Active Galactic Nuclei
• The Connection between X-ray- and Radio-Selected BL Lacertae Objects
• Discovery of >350 GeV Gamma Rays from the BL Lacertae Object 1ES 2344+514
• VHE Gamma Rays from PKS 2155-304
• Variability Pattern and the Spectral Evolution of the BL Lacertae Object PKS 2155-304
• X-ray Emission of Mkn 421: New Clues From Its Spectral Evolution. II. Spectral Analysis and Physical Constraints
• Rapid X-ray Variability of the BL Lacertae Object PKS 2155-304
• Multiwavelength Monitoring of the BL Lac Object PKS 2155-304 I. The IUE Campaign
• Spectral Evolution of PKS 2155-304 observed with BeppoSAX during an Active Gamma-ray Phase
• X-ray Observations of TeV Blazars and Multi-Frequency Analysis

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