Abstract

Contributed Talk - Plenary

Investigation of supernova remnant IC 443 and G189.6+3.3 with LAMOST

G. Paylı, B. Dincel and R. Neuhäuser
Astrophysikalisches Institut und Universitäts-Sternwarte

We present an analysis of the optical emission associated with the supernova remnants (SNRs) G189.6+3.3 and IC 443, based on spectroscopic data obtained with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). All available spectra covering these regions were utilized in the study. Characteristic emission lines of SNRs, including prominent H α, [S ii] and other forbidden lines, were identified and measured from stellar spectra exhibiting low continuum levels (S/N< 10). In the regions northeastern (NE) and east (E) of IC 443, we derive an average [S ii] λλ6716/6731˚A to Hαλ6563 ratio of [S ii]/H α= 0.59±0.12, consistent with moderate shock activity. Within and just beyond the visible boundaries of IC 443, the ratio increases significantly to [S ii]/H α=1.25±0.31, with values reaching up to 1.33 in areas outside the bright filaments, suggesting that the optical extent of IC 443 may be larger than previously estimated. This interpretation aligns with the explosion site inferred from the identification of the pre-supernova binary companion, which is significantly offset from the geometrical center of the SNR. Electron densities (Ne) across the observed region range from 4 to 1257 cm−3, supporting the presence of shock-heated ionized gas. Additionally, we estimate shock velocities, reddening, and interstellar extinction coefficients, and compare these with theoretical predictions. The physical conditions and optical characteristics of the environments surrounding SNR G189.6+3.3 and IC 443 are discussed in detail.