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Post Info TOPIC: G272.2-3.2


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Posts: 131433
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RE: G272.2-3.2
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Title: XMM-Newton and Chandra observations of G272.2-3.2. Evidence of stellar ejecta in the central region
Authors: E. Sánchez-Ayaso, J. A. Combi, F. Bocchino, J. F. Albacete-Colombo, J. López-Santiago, J. Martí, E. Castro

We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant G272.2-3.2, in order to get important constraints on its ionisation stage, on the progenitor supernova explosion, and the age of the remnant. We report combined XMM-Newton and Chandra images, median photon energy map, silicon and sulphur equivalent width maps, and a spatially resolved spectral analysis for a set of regions of the remnant. Complementary radio and H{\alpha} observations, available in the literature, are also used to study the multi-wavelength connection of all detected emissions. The X-ray morphology of the remnant displays an overall structure with an almost circular appearance, a centrally brightened hard region, with a peculiar elongated hard structure oriented along the northwest-southeast direction of the central part. The X-ray spectral study of the regions shows distinct K{\alpha} emission-line features of metal elements, confirming the thermal origin of the emission. The X-ray spectra are well represented by an absorbed VNEI thermal plasma model, which produces elevated abundances of Si, S, and Fe in the circular central region, typical of ejecta material. The values of abundances found in the central region of the SNR favour a Type Ia progenitor for this remnant. The outer region shows abundances below the solar value, as expected if the emission arises from the shocked ISM. The relatively low ionisation timescales suggests non-equilibrium ionisation. We identify the location of the contact discontinuity. Its distance to the outer shock is higher than expected for expansion in a uniform media, what suggests that the remnant spent most of its time in a more dense medium.

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Posts: 131433
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Title: Suzaku study of centrally brightened supernova remnant G272.2-3.2
Authors: A. Sezer, F. Gok

In this work, the results from Suzaku observation of Galactic supernova remnant G272.2-3.2 are presented. Spectra of G272.2-3.2 are well fitted by a single-temperature variable abundances non-equilibrium ionisation (VNEI) model with an electron temperature kTe ~0.77 keV, ionisation timescale {\tau} ~ 6.5 x 10^10 cm-3 s and absorbing column density NH ~1.1 x 10^22 cm-2. We have detected enhanced abundances of Si, S, Ca, Fe and Ni in the center region indicating that the X-ray emission has ejecta origin. We estimated the electron density ne to be ~0.48f^-˝ cm-3, age ~4300f^˝ yr and the X-ray total mass Mx = 475f^˝ M by taking the distance to be d=10 kpc. To understand the origin of the centrally-peaked X-ray emission of the remnant, we studied radial variations of the electron temperature and surface brightness. The relative abundances in the center region suggest that G272.2-3.2 is the result of a Type Ia supernova explosion.

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