期刊
ASTRONOMY & ASTROPHYSICS
卷 598, 期 -, 页码 -出版社
EDP SCIENCES S A
DOI: 10.1051/0004-6361/201629419
关键词
galaxies: active; BL Lacertae objects: individual: PKS 2155-304; gamma rays: galaxies; galaxies: jets; galaxies: nuclei; radiation mechanisms: non-thermal
资金
- German Ministry for Education and Research (BMBF)
- Max Planck Society
- German Research Foundation (DFG)
- French Ministry for Research
- CNRS-IN2P3
- Astroparticle Interdisciplinary Programme of the CNRS
- UK Science and Technology Facilities Council (STFC)
- IPNP of the Charles University
- Czech Science Foundation
- Polish Ministry of Science and Higher Education
- University of Namibia
- Austrian Science Fund (FWF)
- Austrian Federal Ministry for Science, Research and Economy
- University of Adelaide
- Australian Research Council
- EGI Federation
- Innsbruck University
- STFC [ST/N000757/1] Funding Source: UKRI
- Science and Technology Facilities Council [ST/N000757/1, ST/H001972/1] Funding Source: researchfish
Studying the temporal variability of BL Lac objects at the highest energies provides unique insights into the extreme physical processes occurring in relativistic jets and in the vicinity of super-massive black holes. To this end, the long-term variability of the BL Lac object PKS 2155 304 is analyzed in the high (HE, 100MeV < E < 300 GeV) and very high energy (VHE, E > 200 GeV) gamma-ray domain. Over the course of similar to 9 yr of H. E. S. S. observations the VHE light curve in the quiescent state is consistent with a log-normal behavior. The VHE variability in this state is well described by flicker noise (power-spectral-density index beta(VHE) = 1 .10(+ 0 : 10) (0 : 13)) on timescales larger than one day. An analysis of similar to 5.5 yr of HE Fermi-LAT data gives consistent results (beta(HE) = 1 : 20(+ 0 : 21) (0 : 23), on timescales larger than 10 days) compatible with the VHE findings. The HE and VHE power spectral densities show a scale invariance across the probed time ranges. A direct linear correlation between the VHE and HE fluxes could neither be excluded nor firmly established. These long-term-variability properties are discussed and compared to the red noise behavior (beta similar to 2) seen on shorter timescales during VHE-flaring states. The difference in power spectral noise behavior at VHE energies during quiescent and flaring states provides evidence that these states are influenced by different physical processes, while the compatibility of the HE and VHE long-term results is suggestive of a common physical link as it might be introduced by an underlying jet-disk connection.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据