Abstract

GARCIA-DIAZ, Ma. T.; HENNEY, W. J.; LOPEZ, J. A.  and  DOI, T. Velocity Structure in the Orion Nebula: II. Emission line atlas of partially ionized to fully ionized gas. Rev. mex. astron. astrofis [online]. 2008, vol.44, n.1, pp.181-212. ISSN 0185-1101.

We present an atlas⁴ of three-dimensional (position-position-velocity) spectra of the Orion Nebula in optical emission lines from a variety of different ionization stages: [O I] 6300Å, [SII] 6716,6731 Å, [Nil] 6584Å, [SIII] 6312Å, Hα 6563Å, and [O III] 5007 Å. These transitions provide point to point information about the physical structure and kinematics of the nebula at an effective resolution of 3" x 2" x 10 km s^-1 , clearly showing the large scale behavior of the ionized gas and the presence of localized phenomena such as Herbig-Haro outflows. As an example application of the atlas, we present a statistical analysis of the widths of the Hα, [OIII], and [NII] lines that permits a determination of the mean electron temperature in the nebula of (9200 ± 400) K. We also find, in contradiction to previous claims, that the non-thermal line broadening is not significantly different between recombination lines and collisional lines.

Keywords : H II regions; ISM: Herbig-Haro objects; ISM: individual: Orion nebula; techniques: spectroscopy; turbulence.

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