Astronomy and Astrophysics – Astrophysics – High Energy Astrophysical Phenomena
Scientific paper
2011-08-08
Astronomy and Astrophysics
Astrophysics
High Energy Astrophysical Phenomena
Accepted for publication in ApJ; 56pages, 15figures
Scientific paper
We study four young Pulsar Wind Nebulae (PWNe) detected in TeV gamma-rays, G21.5-0.9, G54.1+0.3, Kes 75, and G0.9+0.1, using the spectral evolution model developed and applied to the Crab Nebula in our previous work. We model the evolution of magnetic field and particle distribution function inside a uniformly expanding PWN considering a time-dependent injection from the pulsar and radiative and adiabatic losses. Considering uncertainties in the interstellar radiation field (ISRF) and their distance, we study two cases for each PWN. Because TeV PWNe have a large TeV gamma-rays to X-rays flux ratio, the magnetic energy of the PWNe accounts for only a small fraction of the total energy injected (typically a few x 10^{-3}). The gamma-ray emission is dominated by inverse Compton scattering off the infrared photons of the ISRF. A broken power-law distribution function for the injected particles reproduces the observed spectrum well, except for G0.9+0.1. For G0.9+0.1, we do not need a low energy counterpart because adiabatic losses alone are enough to reproduce the radio observations. High energy power-law indices at injection are similar (2.5 -- 2.6), while low energy power-law indices range from 1.0 to 1.6. The lower limit of the particle injection rate indicates that the pair multiplicity is larger than 10^4. The corresponding upper limit of the bulk Lorentz factor of the pulsar winds is close to the break energy of the broken power-law injection, except for Kes 75.
Takahara Fumio
Tanaka Shuta J.
No associations
LandOfFree
Study of Four Young TeV Pulsar Wind Nebulae with a Spectral Evolution Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Study of Four Young TeV Pulsar Wind Nebulae with a Spectral Evolution Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Study of Four Young TeV Pulsar Wind Nebulae with a Spectral Evolution Model will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-190115