A&A 365, L231-L236 (2001)
DOI: 10.1051/0004-6361:20000231
The X-ray spectrum of the supernova remnant 1E 0102.2-7219
A. P. Rasmussen1, E. Behar1, S. M. Kahn1, J. W. den Herder2 and K. van der Heyden2.1 Columbia Astrophysics Laboratory, 550 West 120th Street, New York, NY 10027, USA
2 University of Utrecht & Space Research Organization of The Netherlands, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
(Received 4 October 2000 / Accepted 10 November 2000)
Abstract
In this letter we present the soft X-ray (5-35 Å) spectrum of
the supernova remnant (SNR) 1E 0102.2-7219 in the Small
Magellanic Cloud, acquired by the reflection grating spectrometers
(RGS) aboard ESA's XMM-Newton Observatory.
Because the RGS features a large dispersion angle, spatial-spectral
confusion is suppressed even for moderately extended
(
) sources. Consequently, these data,
along with the spectrum of N132d (Behar et al. 2001),
provide what are probably the most detailed soft X-ray spectrum of
entire SNRs. The diagnostic power of performing spectroscopy using
groups of emission lines from single ions is demonstrated. In
particular, the bright Lyman and helium series lines for light
elements (CVI, OVII, OVIII, NeIX &
NeX) show peculiar ratios, where the values
are
systematically weaker than expected for electron impact excitation
close to ionization equilibrium, indicating nonequilibrium
ionizing (NEI) conditions in the source.
The well known temperature diagnostics
of helium-like triplets
(OVII & NeIX) confirm this suggestion, with values
that are inconsistent with ionization equilibrium. The temperatures
implied are well above the maximum emission temperature
Tm for
each ion, and consistent with a purely ionizing plasma. The density
diagnostics
R(ne)=f/i meanwhile, are consistent with the
low density limit, as expected.
Key words: atomic processes -line: formation -ISM: individual objects: 1E 0102.2-7219 -galaxies: magellanic clouds -X-rays: ISM
Offprint request: A. P. Rasmussen, arasmus@astro.columbia.edu
SIMBAD Objects
© ESO 2001

BibSonomy
CiteUlike
Del.icio.us
Digg
Facebook
Mendeley
Twitter