A novel approach in constraining electron spectra in blazar jets: The case of markarian 421
| Autor: | Stawarz, Lukasz, Paneque, David, Madejski, Grzegorz, Ostrowski, Michat, Ushio, Masayoshi, Takahashi, Tadayuki, Hayashida, Masaaki, Kataoka, Jun, Tanaka, Yasuyuki T., Tanaka, Takaaki |
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| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Physics
Active galactic nucleus Superluminal motion Cosmology and Nongalactic Astrophysics (astro-ph.CO) Astrophysics::High Energy Astrophysical Phenomena jets [galaxies] FOS: Physical sciences Astronomy and Astrophysics Electron Astrophysics Power law Electromagnetic radiation Spectral line individual (Markarian 421) [BL Lacertae objects] galaxies [X-rays] Particle acceleration Space and Planetary Science active [galaxies] Blazar non-thermal [adiation mechanisms] Astrophysics - Cosmology and Nongalactic Astrophysics acceleration of particles |
| Zdroj: | The Astrophysical Journal. 724(2):1509-1516 |
| ISSN: | 0004-637X |
| Popis: | We report results from the observations of the well studied TeV blazar Mrk 421 with the Swift and the Suzaku satellites in December 2008. During the observation, Mrk 421 was found in a relatively low activity state, with the corresponding 2-10 keV flux of $3 \times 10^{-10}$ erg/s/cm^2. For the purpose of robust constraining the UV-to-X-ray emission continuum we selected only the data corresponding to truly simultaneous time intervals between Swift and Suzaku, allowing us to obtain a good-quality, broad-band spectrum despite a modest length (0.6 ksec) exposure. We analyzed the spectrum with the parametric forward-fitting SYNCHROTRON model implemented in XSPEC assuming two different representations of the underlying electron energy distribution, both well motivated by the current particle acceleration models: a power-law distribution above the minimum energy $\gamma_{\rm min}$ with an exponential cutoff at the maximum energy $\gamma_{\rm max}$, and a modified ultra-relativistic Maxwellian with an equilibrium energy $\gamma_{\rm eq}$. We found that the latter implies unlikely physical conditions within the blazar zone of Mrk 421. On the other hand, the exponentially moderated power-law electron distribution gives two possible sets of the model parameters: (i) flat spectrum $dN'_e/d\gamma \propto \gamma^{-1.91}$ with low minimum electron energy $\gamma_{\rm min} Comment: 18 pages, 2 figures; accepted for publication in the Astrophysical Journal |
| Databáze: | OpenAIRE |
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