On the origin of the system PSR B 175724/SNR G 5.41.2

¹ Sternberg Astronomical Institute, Moscow State University, Universitetskij Pr. 13, Moscow 119992, Russia
² E.K. Kharadze Abastumani Astrophysical Observatory, Georgian Academy of Sciences, A. Kazbegi ave. 2-a, Tbilisi 380060, Georgia
³ Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, PO Box 586, 34100 Trieste, Italy

Corresponding author: vgvaram@sai.msu.ru

Received: 2 June 2003
Accepted: 16 October 2003

Abstract

A scenario for the origin of the system PSR B 1757-24/supernova remnant (SNR) G 5.4-1.2 is proposed. It is suggested that both objects are the remnants of a supernova (SN) that exploded within a pre-existing bubble blown-up by a runaway massive star (the SN progenitor) during the final (Wolf-Rayet) phase of its evolution. This suggestion implies that (a) the SN blast centre was significantly offset from the geometric centre of the wind-blown bubble (i.e. from the centre of the future SNR), (b) the bubble was surrounded by a massive wind-driven shell, and (c) the SN blast wave was drastically decelerated by the interaction with the shell. Therefore, one can understand how the relatively young and low-velocity pulsar PSR B 1757-24 was able to escape from the associated SNR G 5.4-1.2 and why the inferred vector of pulsar transverse velocity does not point away from the geometric centre of the SNR. A possible origin of the radio source G 5.27-0.9 (located between PSR B 1757-24 and the SNR G 5.4-1.2) is proposed. It is suggested that G 5.27-0.9 is a lobe of a low Mach number (1.7) jet of gas outflowing from the interior of G 5.4-1.2 through the hole bored in the SNR's shell by the escaping pulsar. It is also suggested that the non-thermal emission of the comet-shaped pulsar wind nebula originates in the vicinity of the termination shock and in the cylindric region of subsonically moving shocked pulsar wind. The role of magnetized wind-driven shells (swept-up during the Wolf-Rayet phase from the ambient interstellar medium with the regular magnetic field) in formation of elongated axisymmetric SNRs is discussed.