| Description |
Massive stars are important constituents of the interstellar medium (ISM) in our Galaxy and beyond. Their strong feedback processes influence the dynamics, energetics and chemistry of the surrounding interstellar medium both locally and on large scales.
An important question to be answered is the one of cooling and heating mechanisms in regions of massive star formation. In the vicinity of massive stars, heating is provided mostly by far-UV (FUV) and infra-red radiation. Cooling is mostly provided by emission in the fine structure lines of CII. There are however other atomic and molecular lines such as OI, CO, OH and H _2 O which can become significant coolants in the dense, embedded regions of massive star formation.
This early phase when the forming massive star is still deeply embedded in its natal envelope, yet already interacting with, and potentially destroying, its environment through copious amounts of UV radiation, massive outflows and ultra compact HII (UCHII) regions, is an important phase in the star formation process. To understand the heating and cooling balance in this phase, one has to consider the contributions of various radiative and dynamical processes such as the FUV radiation from the young star itself, shocks created by strong stellar winds and the photon dominated regions (PDRs) where the radiation impinges on the molecular material.
The tracers of these processes can be observed in the far-infrared, a wavelength range that is now accessible at unprecedented high spectral and spatial resolution with the Herschel Space Observatory.
We propose to observe the aformentioned tracers of cooling and heating in the massive star forming region IRAS 12326-6245 to obtain a complete picture of the different processes, the regions they originate from and how they interact.
This proposal is for time granted to the HIFI hardware team (PI: Frank Helmich) and to be accounted as part of the Swiss guaranteed time (Lead-Co-I: Arnold O. Benz). |
