Detailed study of SNR G306.3−0.9 using XMM-Newton and Chandra observations

¹ Instituto Argentino de Radioastronomía (CCT La Plata, CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires, Argentina
e-mail: suarez@iar-conicet.gov.ar; fgarcia@iar-conicet.gov.ar; suarez@iar-conicet.gov.ar
² Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900 FWA La Plata, Argentina
³ Deptamento de Ingeniería Mecánica y Minera, Universidad de Jaén, Campus Las Lagunillas s/n Ed. A3, 23071 Jaén, Spain
e-mail: peter@ujaen.es
⁴ Instituto de Astronomía y Física del Espacio (IAFE), CC 67, Suc. 28, 1428 Buenos Aires, Argentina
⁵ FADU and CBC, Universidad de Buenos Aires, 1428 Buenos Aires, Argentina
⁶ Dipartimento di Fisica & Chimica, Università di Palermo, Piazza del Parlamento 1, 90134 Palermo, Italy
⁷ INAF–Osservatorio Astronomico di Palermo, P.zza del Parlamento 1, 90134 Palermo, Italy

Received: 20 July 2015
Accepted: 23 June 2016

Abstract

Aims. We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant (SNR) G306.3−0.9 in detail to obtain constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant.

Methods. We used combined data from XMM-Newton and Chandra observatories to study the X-ray morphology of G306.3−0.9 in detail. A spatially resolved spectral analysis was used to obtain physical and geometrical parameters of different regions of the remnant. Spitzer infrared observations, available in the archive, were also used to constrain the progenitor supernova and study the environment in which the remnant evolved.

Results. The X-ray morphology of the remnant displays a non-uniform structure of semi-circular appearance, with a bright southwest region and very weak or almost negligible X-ray emission in its northern part. These results indicate that the remnant is propagating in a non-uniform environment as the shock fronts are encountering a high-density medium, where enhanced infrared emission is detected. The X-ray spectral analysis of the selected regions shows distinct emission-line features of several metal elements, confirming the thermal origin of the emission. The X-ray spectra are well represented by a combination of two absorbed thermal plasma models: one in equilibrium ionization (VAPEC) with a mean temperature of ~0.19 keV, and another out of equilibrium ionization (VNEI) at a higher temperature of ~1.1 or 1.6–1.9 keV. For regions located in the northeast, central, and southwest part of the SNR, we found elevated abundances of Si, S, Ar, Ca, and Fe, typical of ejecta material. The outer regions located northwest and south show values of the abundances above solar but lower than to those found in the central regions. This suggests that the composition of the emitting outer parts of the SNR is a combination of ejecta and shocked material of the interstellar medium. The comparison between the S/Si, Ar/Si, and Ca/Si abundances ratios (1.75, 1.27, and 2.72 in the central region, respectively), favor a Type Ia progenitor for this remnant, a result that is also supported by an independent morphological analysis using the X-ray and 24 μm IR data.