The faint supernova remnant G 34.7-0.4 (W44)

Flux calibrated images of the known supernova remnant G 34.7-0.4 in basic optical emission lines are presented. The low ionization images show a relatively flat flux distribution. The diffuse and patchy morphology of the detected optical emission may indicate the presence of turbulent magnetic fields. Typical observed H ...] fluxes are ~8 *10^-17 erg s^ -1 cm ^-2 arcsec ^-2, while the [ S II] fluxes are lower around 4 *10^-17 erg s ^-1 cm ^-2 arcsec^ -2. Emission in the medium ionization line of [ O III] and [ N IIand moderate [ O I] 6300 A emission. Shock velocities in the range of 110-150 km s ^-1 and low electron densities are estimated. Archival MSX infrared data show emission in the south and west areas of the remnant matching rather well the optical and radio emission.