45 research outputs found
ASCA and RXTE Observations of Non-Thermal X-ray Emission from Galactic Supernova Remnants: G156.2+5.7
(Abridged) We are conducting a survey of Galactic shell-type supernova
remnants (SNRs) known or suspected to possess non-thermal components to their
X-ray emission using new and archived observations made with such X-ray
satellites as ROSAT, ASCA, RXTE, Chandra and XMM-Newton. This research is
intended to probe the phenomenon of cosmic-ray acceleration by Galactic SNRs
and estimate the maximum energy of cosmic-ray electrons accelerated by these
sources. To illustrate this work, we examine the X-ray spectrum of the
northwestern rim of an SNR suspected to have a non-thermal component to its
X-ray emission, G156.2+5.7 (RX J04591+5147), over the energy range of
approximately 0.7-12.0 keV using observations made by the ASCA GIS and the RXTE
PCA. We compare fits made to the non-thermal component using two models, a
simple power law and SRCUT. Both models give acceptable fits: the photon index
derived from the fit made with the power law model, 2.0 (+0.2, -0.5), is
comparable to values obtained for the bright rims of other SNRs with hard X-ray
spectra. Using the SRCUT model, we derive a value of 2.42 (+0.24, -0.23) x
10^17 Hz for the cutoff frequency: based on this value and assuming a mean
magnetic field strength of 14 microGauss, we estimate the cutoff energy of
cosmic-ray electrons accelerated by G156.2+5.7 to be approximately 32 TeV. This
energy value is well short of the "knee" feature of the cosmic-ray spectrum.Comment: 6 pages with 2 figures. This tex file uses the style file cospar.sty
from Elvesier Science Publishers. To be published in Advances in Space
Research, Proceedings of 34th COSPAR Assembly (October 2002), Symposium E1.4,
"High Energy Studies of Supernova Remnants and Neutron Stars," eds. W.
Hermsen and W. Becker (2003