High Energy Radiation Fields and the Evolution of T Tauri Disks
Dr. Edwin Bergin
University of Michigan
Abstract
In this talk I will discuss the high energy radiation field
of T Tauri stars and how this
radiation influences the chemical and physical evolution
of the proto-planetary disk. I will present new observations
of the far-ultraviolet (FUV) radiation field and the near to
mid-infrared spectral
energy distribution of a sample of T Tauri stars with detectable
and chemically diverse molecular emission. I will examine
the nature of this field and show that there is clear evidence for
Lyman alpha induced molecular hydrogen fluorescence and an
additional source of FUV continuum produced by H2 that may be induced by
stellar X-rays. Energetic radiation and the
an evolving dust opacity (due to coagulation and sedimentation)
are key determinants of the disk chemical evolution and
I will discuss how these various factors influence the chemistry.