Optical observations of the supernova remnant G 69.4+1.2

¹ University of Crete, Physics Department, PO Box 2208, 710 03 Heraklion, Crete, Greece
² Foundation for Research and Technology-Hellas, PO Box 1527, 711 10 Heraklion, Crete, Greece

Corresponding author: F. Mavromatakis, fotis@physics.uoc.gr

Received: 12 December 2001
Accepted: 13 March 2002

Abstract

We performed deep optical observations of the area of the new supernova remnant G 69.4+1.2 in the emission lines of [ ], H ] and [ ]. The low ionization images reveal diffuse and filamentary emission in the central and south, south–west areas of our field. Estimates of the [ ]/Hα ratio suggest that the detected emission in these areas originates from shock heated gas, while the strong extended source in the north must be an  region. The medium ionization image of [ ] shows a single filament close to the field center. Emission from [ ] is not detected elsewhere in the field but only in the north from LBN 069.96+01.35. Deep long–slit spectra taken at the position of the [ ] filament suggest shock velocities ~120 km s^-1, while in other areas velocities around 50 km s^-1 are expected. The sulfur lines ratio indicates electron densities less than 120 cm^-3. The absolute Hα flux is ~5 10^-17 erg s^-1 cm^-2 arcsec^-2. The optical emission is very well correlated with the radio emission, especially in the south west. The soft X–ray emission detected in the ROSAT All-Sky survey shows a satisfactory degree of correlation with the optical data in the south–west suggesting their association.