Evolved Fe-rich supernova remnants in the Large Magellanic Cloud with Athena
Abstract
Recently, a new class of evolved supernova remnants (SNRs) with centrally peaked Fe-rich emission has been identified in the Magellanic Clouds. The Fe-rich cores result from reverse shock-heated ejecta, the composition of which is consistent with a type Ia explosion, and are spectrally evident as very pronounced Fe L-shell emission lines. Observations with the current generation of X-ray facilities show that the interior Fe-rich plasmas exhibit long ionisation ages, requiring higher central densities than expected from standard type Ia models. It has been suggested that the high interior densities are the result of seeding of the circumstellar medium by the stellar companion leading up to the explosion, which could be facilitated by the most massive "prompt" type Ia progenitor systems. Thus far, these studies have focussed on integrated Fe-rich interior emission since these objects are too faint to allow spatially resolved spectral analysis. In addition, the spectral resolution of the current generation CCD detectors cannot resolve the individual lines in the Fe L-shell complex and spectral analysis is hampered by continuing uncertainties in the atomic data for Fe L-shell lines. Spatially resolved, high spectral resolution studies would reveal in detail the plasma conditions in the Fe-rich interior, shedding light on the possible progenitor systems of these objects, as well as providing a test of the Fe L-shell atomic data. The Fe L-shell line complex is known to be a powerful temperature, density, and ionisation condition diagnostic, and the effective area of Athena, coupled with the high spectral resolution of the X-IFU, provide access to this science space. The detections of such objects has grown significantly in recent years due to the XMM-Newton Very Large Programme survey of the Large Magellanic Cloud (LMC) and our ROSAT LMC SNR candidate follow-up programme. In this talk I will review the current sample of centrally peaked Fe-rich SNRs observed with XMM-Newton and illustrate how the Athena X-IFU can allow an unprecedented probe into the Fe-rich plasmas in these objects.
- Publication:
-
Exploring the Hot and Energetic Universe: The first scientific conference dedicated to the Athena X-ray observatory
- Pub Date:
- September 2015
- Bibcode:
- 2015eheu.conf...62K