Astrophysical Journal
Astrophysical Journal
5 years ago

Swift Observations of Mrk 421 in Selected Epochs. I. The Spectral and Flux Variability in 2005–2008

We present detailed results of Swift observations of the nearby TeV-detected blazar Mrk 421, based on the rich archival data obtained during 2005 March–2008 June. The best fits of the 0.3–10 keV spectra were mainly obtained using the log-parabolic model, yielding low spectral curvatures expected in the case of the efficient stochastic acceleration of particles. During strong X-ray flares, the position of the synchrotron spectral energy distribution peak ##IMG## [http://ej.iop.org/images/0004-637X/854/1/66/apjaaa75dieqn1.gif] {${E}_{{\rm{p}}}$} was beyond 8 keV for 41 spectra, while it sometimes was situated at the UV frequencies in quiescent states. The photon index at 1 keV exhibited a broad range, and the values ##IMG## [http://ej.iop.org/images/0004-637X/854/1/66/apjaaa75dieqn2.gif] {$a\lt 1.70$} were observed during the strong flares, hinting at the possible presence of a jet hadronic component. The spectral parameters were ...

Publisher URL: http://iopscience.iop.org/0004-637X/854/1/66

DOI: 10.3847/1538-4357/aaa75d

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.