Protostars and Planets VI, Heidelberg, July 15-20, 2013

Poster 1K033

Investigating Proper Motions in the 2M1207A Jet

Whelan, Emma (Institut für Astronomie & Astrophysik Tuebingen)
Ray, Tom (Dublin Institute for Advanced Studies)
Comeron, Fernando (European Southern Observatory)
Bacciotti, Francesca (INAF-Osservatorio Astrofisico di Arcetri)
Kavanagh, Patrick (Institut für Astronomie & Astrophysik Tuebingen)

Abstract:
The 24 Jupiter Mass brown dwarf (BD), 2MASSJ12073347-3932540 (2M1207A), was first discovered to be driving an outflow through the spectro-astrometric analysis of its [OI]6300 emission region (Whelan et al. 2007). It is now known to drive a bipolar outflow with a position angle (PA) of 65 degrees. [SII] narrowband images obtained by us revealed a series of knots along the PA of the outflow (Whelan et al. 2012). The furthest knot from the BD was bow-shock shaped and these results confirmed for the first time that BD outflows could be well collimated i.e. are jets, and episodic. In order to conduct a proper motion study of the knots we obtained follow-up images in [SII] and Hα using FORS-2 / VLT, in Feb / Jan 2013. The proper motion of the source is an important consideration as it is approximately along the same direction as the jet and likely has a similar magnitude. While no significant proper motion is detected in the [SII] knots there are morphological changes. It is possible that the velocity of the knots has slowed significantly with distance. From the comparison of the [SII] and Halpha images, Halpha seems to trace the shock fronts whereas [SII] the cooling zone behind the shock front. Future work includes simulations the jet to try to understand how the proper motion of source effects the morphology of the jet and the analysis of spectra of the knots. Spectra will facilitate the measurement of the knot velocities

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