LAMOST MRS-N Observation of the W80 Region

Abstract

The spectral observations and analysis for the W80 region are presented by using the data of Medium-Resolution Spectroscopic Survey of Nebulae (MRS-N) with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). A total of 2982 high-quality nebular spectra have been obtained in the 20 square degree field of view which covers the W80 complex, and the largest sample of spectral data has been established for the first time. The relative intensities, radial velocities (RVs), and full widths at half maximum (FWHMs) are measured with the high spectral resolution of LAMOST MRS-N, for Hα λ6563 Å, [N ii] λλ6548 Å, 6584 Å, and [S ii] λλ6716 Å, 6731 Å emission lines. In the field of view of the whole W80 region, the strongest line emissions are found to be consistent with the bright nebulae NGC 7000, IC 5070, and LBN 391, and weak line emissions also exist in the Middle Region, where no bright nebulae are detected by the wide-band optical observations. The large-scale spectral observations of the W80 region reveal the systematic spatial variations of RVs and FWHMs, and several unique structural features. A “curved feature” to the east of NGC 7000, and a “jet feature” to the west of LBN 391 are detected to be showing larger RVs. A “wider FWHM region” is identified in the eastern part of NGC 7000. The variations of [S ii]/Hα ratios display a gradient from southwest to northeast in the NGC 7000 region, and manifest a ring shape around the “W80 bubble” ionized by an O-type star in L935. Further spectral and multi-band observations are guaranteed to investigate in detail the structural features.