Abstract
We consider some implications of the rapid X-ray and TeV variability observed in M87 and the TeV blazars. We outline a model for jet focusing and demonstrate that modest radiative cooling can lead to recollimation of a relativistic jet in a nozzle having a very small cross-sectional radius. Such a configuration can produce rapid variability at large distances from the central engine and may explain recent observations of the HST-1 knot in M87. Possible applications of this model to TeV blazars are discussed. We also discuss a scenario for the very rapid TeV flares observed with H.E.S.S. and MAGIC in some blazars, that accommodates the relatively small Doppler factors inferred from radio observations.
Original language | English |
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Pages (from-to) | 1603-1610 |
Number of pages | 8 |
Journal | International Journal of Modern Physics D |
Volume | 17 |
Issue number | 9 |
DOIs | |
State | Published - Sep 2008 |
Keywords
- Active galaxies
- BL Lacertae objects
- Gamma-rays
- Jets
- Nonthermal radiation mechanism