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Title: TIME-DEPENDENT MODELING OF PULSAR WIND NEBULAE

A spatially independent model that calculates the time evolution of the electron spectrum in a spherically expanding pulsar wind nebula (PWN) is presented, allowing one to make broadband predictions for the PWN's non-thermal radiation. The source spectrum of electrons injected at the termination shock of the PWN is chosen to be a broken power law. In contrast to previous PWN models of a similar nature, the source spectrum has a discontinuity in intensity at the transition between the low- and high-energy components. To test the model, it is applied to the young PWN G21.5-0.9, where it is found that a discontinuous source spectrum can model the emission at all wavelengths better than a continuous one. The model is also applied to the unidentified sources HESS J1427-608 and HESS J1507-622. Parameters are derived for these two candidate nebulae that are consistent with the values predicted for other PWNe. For HESS J1427-608, a present day magnetic field of B{sub age} = 0.4 {mu}G is derived. As a result of the small present day magnetic field, this source has a low synchrotron luminosity, while remaining bright at GeV/TeV energies. It is therefore possible to interpret HESS J1427-608 within the ancient PWN scenario. Formore » the second candidate PWN HESS J1507-622, a present day magnetic field of B{sub age} = 1.7 {mu}G is derived. Furthermore, for this candidate PWN a scenario is favored in the present paper in which HESS J1507-622 has been compressed by the reverse shock of the supernova remnant.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Centre for Space Research, North-West University, Potchefstroom Campus, 2520 Potchefstroom (South Africa)
  2. Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg, Campus Hubland Nord, Emil-Fischer-Str. 31, D-97074 Wuerzburg (Germany)
  3. Landessternwarte, Universitaet Heidelberg, Koenigstuhl 12, D-69117 Heidelberg (Germany)
Publication Date:
OSTI Identifier:
22130960
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 773; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ELECTRON SPECTRA; ELECTRONS; EMISSION; LUMINOSITY; MAGNETIC FIELDS; NEBULAE; PULSARS; SPHERICAL CONFIGURATION; STELLAR WINDS; SUPERNOVA REMNANTS; THERMAL RADIATION; TIME DEPENDENCE