INTEGRAL observations of the blazar Mrk 421 in outburst (Results of a multi-wavelength campaign)

Abstract

We report the results of a multi-wavelength campaign on the blazar Mrk 421 during outburst. We observed four strong flares at X-ray energies that were not seen at other wavelengths (partially because of missing data). From the fastest rise in the X-rays, an upper limit could be derived on the extension of the emission region. A time lag between high-energy and low-energy X-rays was observed, which allowed an estimation of the magnetic-field strength. The spectral analysis of the X-rays revealed a slight spectral hardening of the low-energy (3 - 43 keV) spectral index. The hardness-ratio analysis of the Swift-XRT (0.2 - 10 keV) data indicated a small correlation with the intensity; i. e., a hard-to-soft evolution was observed. At the energies of IBIS/ISGRI (20 - 150 keV), such correlations are less obvious. A multiwavelength spectrum was composed and the X-ray and bolometric luminosities are calculated.

15 pages, 18 figures; accepted by Astronomy & Astrophysics

References in corpus (6)

• Multiwavelength Observations of Markarian 421 in March 2001: an Unprecedented View on the X-ray/TeV Correlated Variability
• Host galaxy subtraction of TeV candidate BL Lacertae objects
• Unveiling the X-ray/TeV engine in Mkn 421
• BAT X-ray Survey - I: Methodology and X-ray Identification
• Simultaneous radio-interferometric and high-energy TeV observations of the gamma-ray blazar Mkn 421
• INTEGRAL and Multiwavelength Observations of the Blazar Mrk 421 during an Active Phase

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• Understanding the X-ray spectral curvature of Mkn 421 using broadband AstroSat observations
• Rapid X-ray Variability in Mkn 421 during a Multiwavelength Campaign
• Correlated Short-Timescale Hard-Soft X-ray Variability of the Blazars Mrk 421 and 1ES 1959+650 using $\text{AstroSat}$
• Long-term hard X-ray variability properties of Swift-BAT blazars
• Investigating the variability of Swift-BAT blazars with NICER
• X-ray Flux and Spectral Variability of the TeV Blazars Mrk 421 and PKS 2155-304