Akademik Veri Yönetim Sistemi
Monthly Notices of the Royal Astronomical Society, cilt.547, sa.4, 2026 (SCI-Expanded, Scopus)
We present optical spectroscopic observations of the supernova remnants (SNRs) G107.7–5.1 and G150.3+4.5, each spanning nearly 3(Formula presented). Both remnants were recently examined in the optical band through a deep H(Formula presented) and [O iii] emission-line imaging survey, which led to the discovery of G107.7–5.1. Using long-slit spectra obtained with the 1.5-m Russian-Turkish Telescope (RTT150), we investigate the physical conditions of the pre-shock and post-shock gas in the optical filamentary regions of the SNRs. The SNR nature of G107.7–5.1 is confirmed by the measured [S ii]/H(Formula presented) and [N ii]/H(Formula presented) ratios, which range from 0.56 to 0.86 and from 0.7 to 1.4, respectively. A similar conclusion is reached for G150.3+4.5, where the observed [S ii]/H(Formula presented) (0.43–0.92) and [N ii]/H(Formula presented) (0.49–1.29) ratios likewise support a shock-excitation origin. Further confirmation of the shock-excited nature of both SNRs comes from their consistency with recent diagnostic diagrams based on multiple emission-line ratios. The [O iii]/H(Formula presented) line ratios measured in both remnants indicate shocks with complete recombination zones and are consistent with shock velocities of (Formula presented) 100 km s(Formula presented). The electron densities ((Formula presented)), derived from the [S ii] (Formula presented) 6716/(Formula presented) 6731 line ratios, exhibit substantial variation in the spectra of both SNRs. Additionally, extinction variations observed across the remnants suggest the presence of significant dust structures along the line of sight. We conclude that these two remnants display remarkable similarities across multiple diagnostic spectral properties, consistent with previous reports indicating comparable GeV gamma-ray characteristics.