The kinematics of the bi-lobal supernova remnant G 65.3+5.7. II.

¹ Institute of Astronomy & Astrophysics, National Observatory of Athens, I. Metaxa & V. Paulou, P. Penteli, 15236 Athens, Greece
² Jodrell Bank Observatory, University of Manchester, Macclesfield SK11 9DL, UK
³ Instituto de Astronomia, UNAM, Apdo. Postal 877. Ensenada, BC 22800, México
⁴ University of Crete, Physics Department, PO Box 2208, 710 03 Heraklion, Crete, Greece
⁵ Dublin Institute for Advanced Studies, School of Cosmic Physics, 5 Merrion Square, Dublin 2, Republic of Ireland
⁶ Astronomical Laboratory, Department of Physics, University of Patras, 26500 Rio-Patras, Greece

Received: 9 March 2004
Accepted: 11 May 2004

Abstract

Further deep, narrow-band images in the light of [O iii] 5007 Å have been added to the previous mosaic of the faint galactic supernova remnant G 65.3+5.7. Additionally, long-slit spatially resolved [O iii] 5007 Å line profiles have been obtained at sample positions using the Manchester Echelle Spectrometer at the San Pedro Martir observatory. The remnant is shown to be predominantly bi-lobal with an EW axis. However, a faint additional northern lobe has now been revealed.
The splitting of the profiles along the slit lengths, when extrapolated to the centre of the remnant, although uncertain, suggests that the expansion velocity of this remnant is between 124 and 187 km s^-1 i.e. much lower than the 400 km s^-1 previously predicted for the forward shock velocity from the X-ray emission.
An expansion proper motion measurement of arcsec in 48 years for the remnant's filamentary edge in the light of Hα + [N ii] 6548 and 6584 Å has also been made. This is combined with an expansion velocity of ≈155 km s^-1, a distance of ≈800 pc is derived.
Several possibilities are considered for the large difference in the expansion velocity measured here and the 400 km s^-1 shock velocity required to generate the X-ray emission. It is also suggested that the morphology of the remnant may be created by a tilt in the galactic magnetic field in this vicinity.