EDP Sciences
Free Access
Issue
A&A
Volume 397, Number 2, January II 2003
Page(s) 693 - 710
Section Formation, structure and evolution of stars
DOI https://doi.org/10.1051/0004-6361:20021545
Published online 17 December 2002


A&A 397, 693-710 (2003)
DOI: 10.1051/0004-6361:20021545

Near-IR echelle spectroscopy of Class I protostars: Mapping Forbidden Emission-Line (FEL) regions in [FeII]

C. J. Davis1, E. Whelan2, T. P. Ray2 and A. Chrysostomou3

1  Joint Astronomy Centre, 660 North A'ohoku Place, University Park, Hilo, Hawaii 96720, USA
2  Dublin Institute for Advanced Studies, School of Cosmic Physics, 5 Merrion Square, Dublin 2, Ireland
3  Department of Physical Sciences, University of Hertfordshire, Hatfield, Herts AL10 9AB, UK

(Received 27 August 2002 / Accepted 22 October 2002 )

Abstract
Near-IR echelle spectra in [FeII] 1.644  $\mu$m 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. 2001 - Paper I). The [FeII] and H 2 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 H 2, 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 H 2 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.


Key words: ISM: jets and outflows -- stars: pre-main-sequence -- ISM: Herbig-Haro objects

Offprint request: C. J. Davis, c.davis@jach.hawaii.edu

SIMBAD Objects



© ESO 2003

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.