XMM-Newton detection of the supernova remnant G304.6 + 0.1 (Kes 17)

¹ Instituto Argentino de Radioastronomía (CCT La Plata, CONICET), C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
e-mail: jcombi@fcaglp.unlp.edu.ar; romero@fcaglp.unlp.edu.ar
² Centro Universitario Regional Zona Atlántica (CURZA). Universidad Nacional del COMAHUE, Monseñor Esandi y Ayacucho 8500, Viedma (Rio Negro), Argentina
e-mail: donfaca@gmail.com
³ Departamento de Física (EPS), Universidad de Jaén, Campus Las Lagunillas s/n, A3, 23071 Jaén, Spain
e-mail: [esayaso:jmarti:ajmunoz:jrssutil]@ujaen.es
⁴ Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900 FWA La Plata, Argentina
⁵ Departamento de Ingeniería Mecánica y Minera, Escuela Politécnica Superior, Universidad de Jaén, Campus Las Lagunillas s/n, A3, 23071 Jaén, Spain
e-mail: peter@ujaen.es
⁶ Departamento de Astrofísica y Ciencias de la Atmósfera, Universidad Complutense de Madrid, 28040 Madrid, Spain
e-mail: jls@astrax.fis.ucm.es

Received: 21 December 2009
Accepted: 30 August 2010

Abstract

Aims. We report the first detailed X-ray study of the supernova remnant (SNR) G304.6 + 0.1, achieved with the XMM-Newton mission.

Methods. The powerful imaging capability of XMM-Newton was used to study the X-ray characteristics of the remnant at different energy ranges. The X-ray morphology and spectral properties were analyzed. In addittion, radio and mid-infrared data obtained with the Molonglo Observatory Synthesis Telescope and the Spitzer Space Telescope were used to study the association with the detected X-ray emission and to understand the structure of the SNR at differents wavelengths.

Results. The SNR shows an extended and arc-like internal structure in the X-ray band without a compact point-like source inside the remnant. We find a high column density of N_H in the range 2.5–3.5 × 10²² cm^-2, which supports a relatively distant location (d ≥ 9.7 kpc). The X-ray spectrum exhibits at least three emission lines, indicating that the X-ray emission has a thin thermal plasma origin, although a non-thermal contribution cannot be discarded. The spectra of three different regions (north, center and south) are well represented by a combination of a non-equilibrium ionization (PSHOCK) and a power-law (PL) model. The mid-infrared observations show a bright filamentary structure along the north-south direction coincident with the NW radio shell. This suggests that Kes 17 is propagating in a non-uniform environment with high density and that the shock front is interacting with several adjacent massive molecular clouds. The good correspondence of radio and mid-infrared emissions suggests that the filamentary features are caused by shock compression. The X-ray characteristics and well-known radio parameters indicate that G304.6 + 0.1 is a middle-aged SNR (2.8−6.4) × 10⁴ yr old and a new member of the recently proposed group of mixed-morphology SNRs.