High resolution X-ray spectroscopy of SN 1987 A: monitoring with XMM-Newton

¹ Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany e-mail: rsturm@mpe.mpg.de
² Max-Planck-Institut für Plasmaphysik, Boltzmannstraße 2, 85748 Garching, Germany

Received: 17 September 2009
Accepted: 1 February 2010

Abstract

Context. The ongoing propagation of the supernova blast wave of SN 1987 A through its inner circumstellar ring has caused a drastic increase in X-ray luminosity in the past few years, which has allowed detailed high resolution X-ray spectroscopy to be performed with the Reflection Grating Spectrometer.

Aims. We report the results of our XMM-Newton monitoring of SN 1987 A, which may be used to follow the detailed evolution of the arising supernova remnant.

Methods. The fluxes and broadening of the numerous emission lines measured in the dispersed spectra provide information about the evolution of the X-ray emitting plasma and its dynamics. These were analyzed in combination with the EPIC-pn spectra, which allow a precise determination of the higher temperature plasma. We modeled individual emission lines and fitted plasma emission models.

Results. For observations between 2003 and 2007 in particular, we detect significant evolution in the plasma parameters and a deceleration of the radial velocity in the lower temperature plasma regions. We detected (at 3σ-level) an iron K feature in the coadded EPIC-pn spectra.

Conclusions. By comparing with Chandra grating observations in 2004, we observe a clear temporal coherence of the spectral evolution and the sudden deceleration of the expansion velocity detectable in X-ray images ~6100 days after the explosion.