Davis, C.J. and Whelan, Emma and Ray, T.P. and Chrysostomou, A. (2003) Near-IR echelle spectroscopy of Class I protostars: Mapping Forbidden Emission-Line (FEL) regions in [FeII]. Astronomy & Astrophysics, 397 (2). pp. 693-710. ISSN 0004-6361

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Abstract

Near-IR echelle spectra in [FeII] 1.644 μm emission trace Forbidden Emission Line (FEL) regions towards seven Class I HH energy sources (SVS 13, B5-IRS1, IRAS 04239+2436, L1551-IRS5, HH 34-IRS, HH 72-IRS and HH 379-IRS) and three classical T Tauri stars (AS 353A, DG Tau and RW Aur). The parameters of these FEL regions are compared to the characteristics of the Molecular Hydrogen Emission Line (MHEL) regions recently discovered towards the same outflow sources (Davis et al. [CITE] – Paper I). The [FeII] and H2 lines both trace emission from the base of a large-scale collimated outflow, although they clearly trace different flow components. We find that the [FeII] is associated with higher-velocity gas than the H2, and that the [FeII] emission peaks further away from the embedded source in each system. This is probably because the [FeII] is more closely associated with HH-type shocks in the inner, on-axis jet regions, while the H2 may be excited along the boundary between the jet and the near-stationary, dense ambient medium that envelopes the protostar. Indeed, there is spatial and kinematic evidence that [FeII] and the more typically-used optical emission lines, the red [SII] doublet, do trace almost the same shock-excited regions in HH jets and FEL regions alike.

Item Type:	Article
Keywords:	ISM: jets and outflows; stars: pre-main-sequence; ISM: Herbig-Haro objects;
Academic Unit:	Faculty of Science and Engineering > Experimental Physics
Item ID:	9933
Depositing User:	Emma Whelan
Date Deposited:	17 Sep 2018 13:22
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	EDP Sciences
Refereed:	Yes
URI:	https://www.aanda.org
Use Licence:	This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available here

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