Tuesday, 18th December at 2.00pm at the JAC
Emma Whelan (Dublin) and Vanessa Agra Amboage (Grenoble)
"Observing the Protostellar Outflow Engine"
ABSTRACT: The phenomenon of mass outflow from young stellar
objects is arguably the most spectacular stage in the formation of
a star. Much work at present is aimed at resolving the outflow
engine, the size of which is estimated at ~ 200AU. While there is
now general agreement that outflows are produced as a by-product
of accretion, observations on a scale of < 200AU are difficult,
primarily due to a lack of spatial resolution. Such observations
are needed to constrain models of jet launching and jet
collimation. To provide information on conditions within the jet
launch region is one of the key aims of the Marie Curie RTN JETSET
programme (www.jetsets.org), of which we are a part.
We will give a brief overview of the techniques used in
the last few years to probe the jet launch region. These
include AO-assisted integral field spectroscopy, HST-STIS
spectroscopy, and spectro-astrometry. Vanessa, who is working on
intergral field spectra (in particular OASIS data) of classical T
Tauri stars, will present her PhD work. Emma has spent much time
applying the technique of spectro-astrometry to studies of
outflows. She will describe this technique and outline some
of her most interesting results to date. These include the use of
spectro-astrometry to detect, for the first time, outflows driven
by brown dwarfs, resolve the outflow component in permitted
emission lines like Pa-beta, and probe dust holes in the disks of
T Tauri stars.
Related Papers:
Ray et al 2007, Protostars & Planets V, Toward Resolving the
Outflow Engine: An Observational Perspective.
Whelan et 2007, 659L, 45, Discovery of a Bipolar Outflow from
2MASSW J1207334-393254, a 24 MJup Brown Dwarf
Whelan et al 2005, Nature 435, 652, A resolved outflow of matter
from a brown dwarf
Whelan et al 2004, A&A, Pab as a tracer of outflow activity in T
Tauri stars as compared to optical forbidden emission.
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