An X-ray study of the SNR G344.7-0.1 and the central object CXOU J170357.8-414302

¹ Instituto Argentino de Radioastronomía (CCT La Plata CONICET), C.C.5, (1894) Villa Elisa, Buenos Aires, Argentina
e-mail: [jcombi;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 Astrofísica y Ciencias de la Atmósfera, Universidad Complutense de Madrid, 28040 Madrid, Spain
e-mail: jls@astrax.fis.ucm.es
⁴ Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque, B1900 FWA La Plata, Argentina
⁵ Departamento de Física (EPS), Universidad de Jaén, Campus Las Lagunillas s/n, A3, 23071 Jaén, Spain
e-mail: [esayaso;jmarti;ajmunoz;jrssutil]@ujaen.es
⁶ 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

Received: 24 November 2009
Accepted: 1 July 2010

Abstract

Aims. We report results of an X-ray study of the supernova remnant (SNR) G344.7-0.1 and the point-like X-ray source located at the geometrical center of the SNR radio structure.

Methods. The morphology and spectral properties of the remnant and the central X-ray point-like source were studied using data from the XMM-Newton and Chandra satellites. Archival radio data and infrared Spitzer observations at 8 and 24 μm were used to compare and study its multi-band properties at different wavelengths.

Results. The XMM-Newton and Chandra observations reveal that the overall X-ray emission of G344.7-0.1 is extended and correlates very well with regions of bright radio and infrared emission. The X-ray spectrum is dominated by prominent atomic emission lines. These characteristics suggest that the X-ray emission originated in a thin thermal plasma, whose radiation is represented well by a plane-parallel shock plasma model (PSHOCK). Our study favors the scenario in which G344.7-0.1 is a 6 × 10³ year old SNR expanding in a medium with a high density gradient and is most likely encountering a molecular cloud on the western side. In addition, we report the discovery of a soft point-like X-ray source located at the geometrical center of the radio SNR structure. The object presents some characteristics of the so-called compact central objects (CCO). However, its neutral hydrogen absorption column (N_H) is inconsistent with that of the SNR. Coincident with the position of the source, we found infrared and optical objects with typical early-K star characteristics. The X-ray source may be a foreground star or the CCO associated with the SNR. If this latter possibility were confirmed, the point-like source would be the farthest CCO detected so far and the eighth member of the new population of isolated and weakly magnetized neutron stars.