Optical Detection of the Emission Nebulae in Nearby Galaxies

Abstract

The standard way for the detection of emission nebulae in optical is by using photometric observations in narrow Hα filter. For this purpose in the most cases the 1.5 to 2 m telescopes are used. For the separation of supernova remnants (SNRs) from HII regions (including the planetary nebulae) the additional observations by using of narrow [SII] filter are necessary. If [SII]/H α ratio > 0.4 an observed nebula should be SNR. Here we present our observations of dwarf galaxies from M81 galaxy group (Holmberg IX, Arps loop) and of galaxy IC342 in order to detect new emission nebulae by using 2 m telescope of Rozhen observatory in Bulgaria. Our campaign started in 2007 and continues until now. In future, beside of Rozhen telescope, we plan to use new 1.5 m telescope, which will be mounted at the Astronomical Station of Vidojevica (ASV) for purpose of detection of new emission nebulae in nearby galaxies for the collecting of robust sample for the theoretical and statistical analyzes.