A nebular analysis of the central Orion nebula with MUSE. Issue 4 (3rd December 2015)

• Record Type: Journal Article
• Authors: Mc Leod, A. F.; Weilbacher, P. M.; Ginsburg, A.; Dale, J. E.; Ramsay, S.; Testi, L.
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 455:Issue 4(2016)
• Page Start: 4057
• Page End: 4086
• Publication Date: 2015-12-03
• Subjects: ISM: abundances -- H ii regions -- ISM: individual objects: M 42 -- ISM: jets and outflows; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stv2617
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: A nebular analysis of the central Orion nebula and its main structures is presented. We exploit observations from the integral field spectrograph Multi Unit Spectroscopic Explorer (MUSE) in the wavelength range 4595–9366 Å to produce the first O, S and N ionic and total abundance maps of a region spanning 6 arcmin × 5 arcmin with a spatial resolution of 0.2 arcsec. We use the S 23 (=([S ii ] λλ6717, 6731+[S iii ] λ9068)/Hβ) parameter, together with [O ii ]/[O iii ] as an indicator of the degree of ionization, to distinguish between the various small-scale structures. The only Orion bullet covered by MUSE is HH 201, which shows a double component in the [Fe ii ] λ8617 line throughout indicating an expansion, and we discuss a scenario in which this object is undergoing a disruptive event. We separate the proplyds located south of the Bright Bar into four categories depending on their S 23 values, propose the utility of the S 23 parameter as an indicator of the shock contribution to the excitation of line-emitting atoms, and show that the MUSE data are able to identify the proplyds associated with discs and microjets. We compute the second-order structure function for the Hα, [O iii ] λ5007, [S ii ] λ6731 and [O i ] λ6300 emission lines to analyse the turbulent velocity field of the region covered with MUSE. We find that the spectral and spatial resolution of MUSE are not able to faithfully reproduce the structure functions of previous works.