Mapping the emission line strengths and kinematics of Supernova Remnant S147 with extensive LAMOST spectroscopic observations

TL;DR

This study uses extensive LAMOST spectroscopic data to map the emission line strengths and kinematics of supernova remnant S147, revealing detailed velocity and line ratio variations across the nebula.

Contribution

It provides the first detailed spatially-resolved maps of emission lines and velocities of S147 using a large dataset, improving understanding of its filamentary structure.

Findings

Radial velocity varies from -100 to 100 km/s across S147.

Line intensity ratios show larger variation than previously reported.

Maps correlate well with filamentary structure of the nebula.

Abstract

We present extensive spectroscopic observations of supernova remnant (SNR) S147 collected with the Large sky Area Multi-Object fiber Spectroscopic Telescope (LAMOST). The spectra were carefully sky-subtracted taking into account the complex filamentary structure of S147. We have utilized all available LAMOST spectra toward S147, including sky and stellar spectra. By measuring the prominent optical emission lines including H{\alpha}, [NII]{\lambda}6584, and [SII]{\lambda}{\lambda}6717,6731, we present maps of radial velocity and line intensity ratio covering the whole nebula of S147 with unprecedented detail. The maps spatially correlated well with the complex filamentary structure of S147. For the central 2 deg of S147, the radial velocity varies from -100 to 100 km/s and peaks between ~ 0 and 10 km/s. The intensity ratios of H{\alpha}/[SII]{\lambda}{\lambda}6717,6731, [SII]{\lambda}6717/{\lambda}6731 and H{\alpha}/[NII]{\lambda}6584 peak at about 0.77, 1.35 and 1.48, respectively, with a scatter of 0.17, 0.19 and 0.37, respectively. The intensity ratios are consistent with the literature values. However, the range of variations of line intensity ratios estimated here and representative of the whole nebula, are larger than previously estimated.