SOF09104
Magnetic Fields at the Onset of Star Formation: Polarization Mapping of Infrared Dark Clouds
Abstract
Most stars are born in clusters, so the processes that initiate star cluster formation are of fundamental
importance throughout astrophysics. Infrared Dark Clouds (IRDCs) are now recognized as the likely precursors
of star clusters. Thus it is important to understand the physical processes that control IRDC formation and
evolution. We propose to observe 214 micron polarized emission from dust in a sample of nine well-studied
IRDCs. These clouds have been mapped extensively with many other facilities, including IRAM 30m and
ALMA to study the kinematics of the molecular gas that reveals properties of the turbulent motions. However,
the B-field morphology and strength in these IRDCs are currently very poorly explored, thus motivating this
SOFIA-HAWC+ proposal. Polarized emission is expected to be well-detected in many independent positions
over the clouds. Sophisticated numerical simulations of magnetized clouds will also be used to help interpret the
observations. We also request GBT-Argus time to map 13CO(1-0) and C18O(1-0) at high angular and velocity
resolution to obtain the highest spatial dynamic range maps of molecular gas kinematics. Analysis of these
maps will yield independent estimates of B-field properties, which will be compared with those derived from
the HAWC+ observations. This will provide important tests of the fidelity of polarized dust emission methods
of magnetic field estimation. Using all these methods, this project will enable a much improved understanding
of the importance of B-fields in IRDCs and thus for the onset of star cluster formation.
Investigators
| Name | Institution |
|---|---|
| Larry Morgan | Green Bank Observatory |
| Giuliana Cosentino | London, University College |
| Francesco Fontani | Istituto Nazionale di Astrofisica |
| Jonathan Tan * | Virginia, University of; Chalmers University Of Technology |
| Felipe Alves | Max-Planck-Institut für extraterrestrische Physik |
| Ashley Barnes | European Southern Observatory; Liverpool John Moores University; Bonn, Universität |
| Paola Caselli | Max-Planck-Institut für extraterrestrische Physik; Leeds, University of |
| Blakesley Burkhart | Center for Astrophysics | Harvard & Smithsonian |
| Jonathan Henshaw | Max-Planck-Institut für Astronomie; Liverpool John Moores University |
| Izaskun Jimenez-Serra | Centro de Astrobiología |
| CHI YAN LAW | Istituto Nazionale di Astrofisica |
| Wanggi Lim | Universities Space Research Association |
| Natalie Butterfield | National Radio Astronomy Observatory; Green Bank Observatory; Iowa, University of; Villanova University |
* indicates the PI