|
|
Paper: |
X-rays at the End of the Main Sequence |
Volume: |
448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun |
Page: |
1231 |
Authors: |
Robrade, J.; Schmitt, J. H. M. M. |
Abstract: |
We present results from XMM-Newton and Chandra observations of very low-mass stars.
These X-ray observations quite frequently detect, besides large flares, also their quasi-quiescent emission.
Our analysis shows that stars down to the bottom of the main sequence are able to generate X-ray emission at high activity levels of
log LX/Lbol = -3 … –4, similar to more massive stars operating a
solar-type dynamo. However, in very low-mass stars the highly active phase may persist over Gyr,
significantly longer than for more massive stars or brown dwarfs. We further discuss examples of
strong X-ray flares produced by these stars.
Altogether, the X-ray properties require the presence of an efficient dynamo mechanism that is
capable of generating the igneous coronae of very low-mass stars. |
|
|
|
|