Cool Stars 14 - Submitted Abstract # 98
This version created on 05 October 2006

Highlights of the XMM-Newton Extended Survey of the Taurus Molecular
Cloud (XEST)


Manuel Guedel, PSI Switzerland
Kevin Briggs,  PSI Switzerland
Kaspar Arzner, PSI Switzerland
Marc Audard, Columbia University, USA
Jerome Bouvier, LAOG Grenoble, Fr
Catherine Dougados, LAOG Grenoble, Fr
Eric Feigelson, PennState, USA
Elena Franciosini, Palermo, It
Adrian Glauser,  PSI Switzerland
Nicolas Grosso, LAOG Grenoble, Fr 
Sylvain Guieu, LAOG Grenoble, Fr 
Francois Menard, LAOG Grenoble, Fr 
Giusi Micela, Palermo, It
Jean-Louis Monin, LAOG Grenoble, Fr
Thierry Montmerle, LAOG Grenoble, Fr 
Deborah Padgett, Caltech, USA
Francesco Palla, Arcetri, It
Ignazio Pillitteri, Palermo, It
Luisa Rebull, Caltech, USA
Luigi Scelsi, Palermo, It
Bruno Silva, Porto Univ., Pt 
Stephen Skinner, Colorado Univ., USA
Beate Stelzer, Palermo, It
Alessandra Telleschi, PSI Switzerland

The `XMM-Newton Extended Survey of the Taurus Molecular Cloud' (XEST)
is a large program designed to systematically investigate the X-ray
properties of young objects in Taurus.  The project makes use of 28
XMM-Newton observations of the most populated ~5 square degrees of the
cloud, including imaging and spectroscopy from the EPIC and RGS
instruments, and also using UV/U-band data from the Optical Monitor.
Complementary data from the Chandra archive are used as well.  Among
the highlights are:  i) A systematic comparison of X-ray emission from
WTTS and CTTS finds differences in the electron temperature structure;
a `soft excess' is found in grating spectra of accreting stars.  ii)
Half of the surveyed brown dwarfs have been detected;  the X-ray
fractional luminosity declines from M dwarfs to BDs;  one BD showed a
possible accretion event in the U band.  iii) A soft component in
two-absorber spectra of jet-driving TTS is attributed to jet shocks.
iv) The first X-ray grating spectrum of a Herbig star reveals very
soft emission.  v) Optical/UV variability is mostly uncorrelated with
X-rays, except in flares, although CTTS clearly show a UV/U excess.
vi) X-ray variability is predominantly seen in the harder band, with
no statistical difference between CTTS and WTTS, suggesting a common,
coronal origin.  vii) Contrary to previous reports, there appears to
be no rotation-activity relation among the Taurus TTS.  viii) A total
of 57 new candidate members of the Taurus clouds are reported.  We
present an overview of the above highlights.

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