Disk evolution -- Poster Presentation
The discovery of extreme disk-jet systems in the Rosette Nebula
Jinzeng Li, National Astronomical Observatory, Chinese Academy of Sciences
Travis A. Rector (U. of Anchorage, Alaska)
We've discovered a set of primarily two extreme jet systems,
namely Rosette HH1 & HH2, in the Rosette Nebula (ApJ Letters 600,
67; ChJAA Letters, 3, 495). Contrary to all other known Herbig-Haro jets
associated with star forming regions, the Rosette jets are found to have
a high excitation nature due to disruptive interaction with the violent
environment they reside in. These disk-jet systems are directly exposed
to the fierce UV radiation fields of dozens of massive OB stars at the
center of NGC 2244, which is the source of ionization that created the
spectacular HII region, the Rosette Nebula. High-resolution spectroscopic
observations of the Rosette HH1 source shows no evidence of veiling in
its continuum though it contrarily displays distinct signiture of
enhanced accretion. This leads to conclusions of fast disk dissipation
and a different jet formation mechanism under the extreme environment of
Rosette. We mention, for the first time, that this offers a potential
evolution solution for the formation of brown dwarfs and free-floating
giant planets in HII regions and cluster forming environments.