2005A&A...440..569A -
Astronomy and Astrophysics, volume 440, 569-581 (2005/9-3)
A search for shock-excited optical emission from the outflows of massive young stellar objects.
ALVAREZ C. and HOARE M.G.
Abstract (from CDS):
We have searched for optical shock-excited emission lines in the outer parts of the bipolar outflows from massive young stellar objects where the flow terminates and the extinction is expected to be low. The Taurus Tunable Filter (TTF) at the Anglo-Australian Telescope (AAT) was used to obtain narrow-band (12-15Å) images of the Hα, [NII]6583, and [S II]6717/6731 lines around
MonR2IRS3,
S255IRS1/3,
GL961 and
GL989. No clear examples of shocked emission were found. A bow shock feature in the
GL989 region maybe related with the molecular outflow NGC 2264D. A weak optical bow-like feature is seen in
GL961, but which of the stars in the cluster is the driving source cannot be uniquely identified. Other emission line features were found in MonR2 and S255 that are consistent with an HII region origin. The observed fluxes and the upper limits were compared with predictions from radiative shock models available in the literature. Any head-on collisions of a jet with speeds of the order of 500km/s should have been detected if the extinction A
v<10mag. Estimates of the extinction in the outer parts of the molecular clouds are somewhat lower than this, although it is possible that it could be higher local to any interaction regions due to swept up material. If the extinction is low, then the shocks must either be slower (<150km/s) or very oblique (>75°), which would argue against the presence of highly collimated jets from high mass young stellar objects.
Abstract Copyright:
∼
Journal keyword(s):
stars: formation - ISM: jets and outflows
Nomenclature:
Table 2: [AH2005] Mon R2 A (Nos A-C), [AH2005] S255 A (No. A), [AH2005] GL 961 A (Nos A-B), [AH2005] GL 989 A (No. A). Table 3: [AH2005] Mon R2W N (Nos R2N 1 to 3, R2S 1 to 2), [AH2005] S255 N (Nos 1-8), [AH2005] GL 961 N (Nos 1-2), [AH2005] GL 989 NN (Nos 1-13).
CDS comments:
in ref list ALLEN 1972ApL....12..231A instead of ApJ.12.231
Simbad objects:
64
View the references in ADS