Discovery of optical emission associated with the supernova remnant G107.5−1.5

ABSTRACT We present the first results from an imaging and a spectroscopic survey of optical emission associated with supernova remnant (SNR) G107.5−1.5. discovered diffuse filamentary G107.5−1.5 using 1.5- 1-m telescopes. The emissions North-East (NE) North-West (NW) regions show structure, while South-East (SE) East (E) structure. From long-slit spectra, we found [S ii]/H α > 0.5 for SE E regions, which supports origin being shock-heated gas. average ratio is to be ∼0.4 ∼0.3 NW NE respectively, indicating that coming ionized gas in H ii region. ratios ii]λλ 6716/6731, estimate electron density ∼2400 cm−3 region, can attributed dense 6716/6731 are ∼1.25 ∼1.15 indicative low-electron density.