Presentation 1 : Oral
Contraints on the ejection process in young stars
C. Dougados, S. Cabrit, P. Garcia, L. Lopez-Martin, J. Ferreira
I will review in this talk new constraints on the launching and ionization
mechanisms of jets from young stars, recently obtained by our group from
the comparison of sub-arcsecond optical observations of the innermost
regions ((d $<$ 500 AU) of T Tauri microjets with models of MHD disk winds
and jet heating. I will also discuss how higher angular resolution observations could
further constrain MHD disk wind models. In particular, I will present
new predictions of jet emission in the infrared [Fe II] lines, and
discuss the potential of this wavelength domain for the study of the
innermost regions of winds, in the context of the future NAOS/VLT and
Amber/VLTI instruments.
Presentation 2 : Poster
A survey for substellar mass objects in Taurus with the CFH12k camera (PNPS)
C. Dougados, F. Menard, E. Magnier, J.C. Cuillandre, G. Fahlman, E. Martin, J. Bouvier
We have used the CFH12k camera to survey 3.6 square degrees in the Taurus
star forming region at R,I,z' down to completeness limits of 22.5,21.5 and
22. Recent studies targetted towards the highest stellar density regions
and limited to 0.7 sq degrees have failed to detect new members at spectral types
later than M6.5, suggesting a possible deficiency of brown dwarfs in Taurus.
At the age of the Taurus association, we are sensitive down to 0.025
msun typically, ie well into the brown dwarf regime, for Av < 10. Combining
the optical data with 2 Mass photometry, we identify 70 photometric candidates.
From a preliminary spectroscopic survey we have discovered 4 brown dwarfs with
spectral types M7-M8 V, the latest type Taurus members to date.