The formation of planetary disks and winds: an ultraviolet view

Abstract

Planetary systems are angular momentum reservoirs generated during star formation. This accretion process produces very powerful engines able to drive the optical jets and the molecular outflows. A fraction of the engine energy is released into heating thus the temperature of the engine ranges from the 3000K of the inner disk material to the 10MK in the areas where magnetic reconnection occurs. There are important unsolved problems concerning the nature of the engine, its evolution and the impact of the engine in the chemical evolution of the inner disk. Of special relevance is the understanding of the shear layer between the stellar photosphere and the disk; this layer controls a significant fraction of the magnetic field building up and the subsequent dissipative processes ougth to be studied in the UV.This contribution focus on describing the connections between 1 Myr old suns and the Sun and the requirements for new UV instrumentation to address their evolution during this period. Two types of observations are shown to be needed: monitoring programmes and high resolution imaging down to, at least, milliarsecond scales.

The Fresnel space imager as a disk evolution watcher

“…1). The radius of the extended magnetosphere is a complex function of the field geometry and extent [19] and can be roughly estimated to be 4.4R for standard stellar parameters [13]. This interaction has a profound influence on the star and the accretion flow but also acts as a dynamo that transform part of the angular momentum excess in the inner disk into magnetic field amplification that self-regulates through quiescent periods of field building-up and eruptions when the energy excess is released.…”