EDP Sciences
Free access
Issue
A&A
Volume 382, Number 3, February II 2002
Page(s) 1021 - 1031
Section Formation, structure and evolution of stars
DOI http://dx.doi.org/10.1051/0004-6361:20011680


A&A 382, 1021-1031 (2002)
DOI: 10.1051/0004-6361:20011680

Near-infrared Fabry-Perot imaging of Herbig-Haro energy sources: Collimated, small-scale H $\mathsf{_{2}}$ jets and wide-angled winds

C. J. Davis1, L. Stern1, 2, T. P. Ray3 and A. Chrysostomou4

1  Joint Astronomy Centre, 660 North A'ohoku Place, University Park, Hilo, Hawaii 96720, USA
2  Dept. of Physics, University of Victoria, PO Box 3055 STN CSC, Victoria, BC V8W 3P6, Canada
3  Dublin Institute for Advanced Studies, School of Cosmic Physics, 5 Merrion Square, Dublin 2, Ireland
4  Department of Physical Sciences, University of Hertfordshire, Hatfield, Herts AL10 9AB, UK

(Received 17 September 2001 / Accepted 23 November 2001)

Abstract
To search for further evidence of H 2 line emission towards the central engines of Herbig-Haro (HH) flows we have obtained near-infrared Fabry-Perot images of eight Class I outflow sources (SVS 13 [HH 7-11], L 1551-IRS5, HH 26-IRS, HH 72-IRS, SSV 63E [HH 24C], SSV 63W [HH 24J], HH 34-IRS and HH 111-IRS) and two Class 0 sources (HH 24-MMS and HH 25-MMS). Elongated H 2 emission (on scales of a few arcseconds) is detected from four of the Class I YSOs. These small-scale "jets" are associated with the base of more extended, parsec-scale HH outflows (and the "Molecular Hydrogen Emission Line" regions, or MHELs, discussed in Davis et al. 2001). In L 1551-IRS 5 we detect two jet components in H 2; these may be the molecular counterparts of the two known optical jets from this binary protostellar system, or they may represent H 2 excitation along the walls of a narrow, edge-brightened cavity. In addition to the small-scale MHEL jets, analysis of the data also suggests the presence of discrete molecular shock fronts formed along the jet axes close to the energy sources. In the most clear-cut example, SVS 13, we see an H 2 knot at a distance of about 440 AU from the outflow source; assuming a flow velocity of ~200 km s -1, then the dynamical age of this molecular feature is only 10 yrs. In these data we also see evidence for both collimated jets and wide-angled winds from the same sources. Indeed, even in one of the two Class 0 sources, HH 25MMS, a poorly-collimated flow component seems to be present. A two-component wind model may therefore be appropriate for outflows from Class I (and possibly even Class 0) protostars.


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

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

SIMBAD Objects



© ESO 2002

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access.

An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account.
    In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.