EVOLUTION of HIGH-ENERGY PARTICLE DISTRIBUTION in MATURE SHELL-TYPE SUPERNOVA REMNANTS

Houdun Zeng, Yuliang Xin, Siming Liu, J. Randy Jokipii, Li Zhang, Shuinai Zhang

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

Multi-wavelength observations of mature supernova remnants (SNRs), especially with recent advances in γ-ray astronomy, make it possible to constrain energy distribution of energetic particles within these remnants. In consideration of the SNR origin of Galactic cosmic rays and physics related to particle acceleration and radiative processes, we use a simple one-zone model to fit the nonthermal emission spectra of three shell-type SNRs located within 2 on the sky: RX J1713.7-3946, CTB 37B, and CTB 37A. Although radio images of these three sources all show a shell (or half-shell) structure, their radio, X-ray, and γ-ray spectra are quite different, offering an ideal case to explore evolution of energetic particle distribution in SNRs. Our spectral fitting shows that (1) the particle distribution becomes harder with aging of these SNRs, implying a continuous acceleration process, and the particle distributions of CTB 37A and CTB 37B in the GeV range are harder than the hardest distribution that can be produced at a shock via the linear diffusive shock particle acceleration process, so spatial transport may play a role; (2) the energy loss timescale of electrons at the high-energy cutoff due to synchrotron radiation appears to be always a bit (within a factor of a few) shorter than the age of the corresponding remnant, which also requires continuous particle acceleration; (3) double power-law distributions are needed to fit the spectra of CTB 37B and CTB 37A, which may be attributed to shock interaction with molecular clouds.

Original languageEnglish (US)
Article number153
JournalAstrophysical Journal
Volume834
Issue number2
DOIs
StatePublished - Jan 10 2017

Fingerprint

supernova remnants
particle energy
shell
particle acceleration
shock
energy
energetic particles
rays
nonthermal radiation
energetics
molecular clouds
radio
astronomy
power law distribution
sky
energy distribution
synchrotron radiation
emission spectra
cut-off
energy dissipation

Keywords

  • cosmic rays
  • gamma rays: ISM
  • ISM: supernova remnants
  • radiation mechanisms: non-thermal

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

EVOLUTION of HIGH-ENERGY PARTICLE DISTRIBUTION in MATURE SHELL-TYPE SUPERNOVA REMNANTS. / Zeng, Houdun; Xin, Yuliang; Liu, Siming; Jokipii, J. Randy; Zhang, Li; Zhang, Shuinai.

In: Astrophysical Journal, Vol. 834, No. 2, 153, 10.01.2017.

Research output: Contribution to journalArticle

Zeng, Houdun ; Xin, Yuliang ; Liu, Siming ; Jokipii, J. Randy ; Zhang, Li ; Zhang, Shuinai. / EVOLUTION of HIGH-ENERGY PARTICLE DISTRIBUTION in MATURE SHELL-TYPE SUPERNOVA REMNANTS. In: Astrophysical Journal. 2017 ; Vol. 834, No. 2.
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