EDP Sciences
Free access
Issue
A&A
Volume 365, Number 1, January I 2001
First Results from XMM-Newton
Page(s) L212 - L217
DOI http://dx.doi.org/10.1051/0004-6361:20000114


A&A 365, L212-L217 (2001)
DOI: 10.1051/0004-6361:20000114

New light on the X-ray spectrum of the Crab Nebula

R. Willingale1, B. Aschenbach2, R. G. Griffiths1, S. Sembay1, R. S. Warwick1, W. Becker2, A. F. Abbey1 and J.-M. Bonnet-Bidaud3.

1  Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK
2  Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85740 Garching, Germany
3  Service d'Astrophysique DAPNIA/SAp, CE Saclay, 91191 Gif-sur-Yvette, France

(Received 2 October 2000 / Accepted 6 November 2000)

Abstract
XMM-Newton observations of the Crab provide new information on its integrated X-ray spectrum and the variation of the spectral form across the nebula. The Crab pulsar and its surrounding torus exhibit the hardest spectra with power-law indices of $\Gamma = 1.6$ and 1.8. The jet and outer reaches of the nebula are significantly softer with $\Gamma = 2.1$ and 2.3 respectively. For the whole nebula, the huge number of recorded counts allows a detailed examination of the soft X-ray absorption due to cool gas in the foreground of the Crab. Absorption edges due to oxygen and neon are clearly identified. Oxygen and iron in the interstellar medium are underabundant by a factor of $0.63 \pm 0.01$. The average $N_{\rm H}=3.45\pm0.02 10^{21}$ cm-2 and varies by less than $\pm11\%$ on a scale equal to or larger than 20 arcsec over the face of the nebula. These observations of the Crab provide an excellent demonstration of the power of the EPIC cameras on XMM-Newton for spatial, spectral and timing studies.


Key words: ISM: supernova remnants -ISM: individual: Crab Nebula

Offprint request: R. Willingale

SIMBAD Objects



© ESO 2001

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.