X-ray Emission at the Substellar Boundary: Young Brown Dwarfs in Taurus-Auriga

We propose for XMMNewton observations of young Brown Dwarfs (BD) and BrownDwarf Candidates (BDC) in the Taurus star forming region. In order to probemagnetic activity in the substellar regime we plan to observe four objects ofdifferent spectral type, i.e. mass, from M6 to M8. This will shed light on therelation between bolometric and Xray luminosity. Together with photometricobservations we will be able to test the rotationactivity connection, as wellas the influence of accretion onto magnetic activity. These relations arecrucial to determine the nature of the dynamo in fully convective objects. YoungBDs are particularly suited for such studies because they are luminous.Comparison to old field BDs will allow to constrain the evolution of activity for very lowmass objects. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]