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Session 50 - Molecular Outflows, Stellar Jets, and Herbig-Haro Objects.
Display session, Tuesday, January 14
Metropolitan Ballroom,

[50.06] The YSO LkH\alpha234 Outflow. Fluorescence in the Near Infrared.

A. Noriega-Crespo (IPAC), P. M. Garnavich (CfA), N. King (NMSU), K. -H. Böhm (UW), A. C. Raga (IAUNAM)

Near infrared images at the 2.121\mum line of H_2 and nearby continuum of the LkH\alpha234 outflow obtained with the APO 3.5m telescope and GRIM II IR camera are presented. Optical images [1] have shown a collimated jet arising from a Herbig Ae/Be star and into a cavity surrounded by a dense cloud. The eastern edge of the cloud is seen as a snaking 'reflection nebula'. The IR images show the jet [1][2] and some evidence for a counter-jet, but also that the 'reflection snake' is bright and well defined in the 2.121\mum line. The spectrum of a small section of this snake obtained with the MMT and Rieke FSPEC IR spectrometer confirms that the IR emission is not due to reflection. The spectrum shows no Br\gamma emission, but displays a number of H_2 features including a strong 8-6 O 2.0412\mum line. This line appears in planetary nebulae and is considered a clear evidence of fluorescence [3]. The high luminosity Herbig Ae/Be source that drives the outflow could be also responsible for the H_2 fluorescent emission. [1] Ray, Poetzel, Solf amp; Mundt (1990). ApJ, 357, L45.

[2] Cabrit, Lagage, McCaughrean amp; Olofsson (1996). Preprint. [3] Shupe, Larkin, Knop, Armus, Matthews amp; Soifer (1996). Preprint.

Program listing for Tuesday