The Galactic Plane region near

II. A stellar wind bubble surrounding SNR 3C 434.1

¹ National Research Council of Canada, Herzberg Institute of Astrophysics, Dominion Radio Astrophysical Observatory, PO Box 248, Penticton, BC V2A 6J9 Canada
² Dept. of Physics, University of Alberta, Edmonton, Alberta, T6G 2J1 Canada
³ Dept. of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 Canada
⁴ Dept. of Physics and Astronomy, The University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4 Canada

Corresponding author: T. Foster, Tyler.Foster@nrc-cnrc.gc.ca

Received: 1 September 2003
Accepted: 19 November 2003

Abstract

New Canadian Galactic Plane Survey 21 cm line observations towards supernova remnant (SNR) 3C 434.1 (G94.0+1.0) are presented. We find a fragmented and thin-walled atomic hydrogen shell inside which the SNR is seen to be contained at 80 km s^-1, which we report to be a highly evolved stellar wind bubble (SWB) associated with the remnant. A dark area in the midst of otherwise bright line emission is also seen near -71 km s^-1. An absorption profile to the extragalactic continuum source 4C 51.45 (superimposed on the shell's north face) allows us to probe the shell's optical depth, kinetic temperature and expansion velocity. The material in the dark area has the same properties as material in the fragmented shell, suggesting that the dark area is actually the far-side “cap” of the shell seen absorbing emission from warm background gas, the first instance of Self Absorption (HISA) seen in such a structure. We show that the kinematic distance of 10 kpc derived from a flat Galactic rotation model is highly improbable, and that this bubble/SNR system is most likely resident in the Perseus Spiral Arm, lying 5.2 kpc distant. We model the SWB shell in three dimensions as a homologously expanding ellipsoid. Physical and dynamical characteristics of the bubble are determined, showing its advanced evolutionary state. Finally, from a photometric search for one or more stars associated with the SWB, we determine that three B0V stars and one O4V star currently inhabit this bubble, and that the progenitor of 3C 434.1 was at latest also an O4 type star.