Cool Stars 14 - Submitted Abstract # 97
This version created on 05 October 2006

DROXO:  X-ray Flares and Coronal Structures in Rho Ophiuchi


Ettore Flaccomio, INAF - OAPA
Beate Stelzer, INAF - OAPA
Ignazio Pillitteri, INAF - OAPA
Giusi Micela, INAF - OAPA
Fabio Reale, INAF - OAPA
Salvo Sciortino, INAF - OAPA

We present time resolved spectroscopy of bright X-ray flares from
young PMS stars observed during the Deep Rho Ophiuchi XMM-Newton
Observation (DROXO).  Because of its long exposure time, 450  Ks,
DROXO is so far the best dataset for the study of X-ray time
variability in the Rho Oph ~1 Myr stellar population and of their
flares in particular.  We interpret the observed time-evolution of the
plasma temperatures and emission measures by assuming that X-rays are
emitted by plasma confined in magnetic loops and subject to both
impulsive and sustained heating.  We thus estimate the length of the
magnetic loops, the minimum strength of the confining magnetic fields
and the densities of the flaring plasma.  We finally compare our
results for the very young Rho Ophiuchi YSOs with similar ones
obtained, with the same method, for more evolved young stars, e.g.  in
the Orion Nebula Cluster (1-2 Myr) and in the Upper Scorpius
association (~5 Myr).

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