GBT Measurements of the Zeeman Effect in the Eridanus/Orion Region
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UC Berkeley the Zeeman Effect in the Eridanus/Orion Region Tim Robishaw Carl Heiles
description
GBT Measurements of the Zeeman Effect in the Eridanus/Orion Region. Tim Robishaw Carl Heiles. UC Berkeley. The Orion Molecular Cloud Complex. Heiles 1997. Hat Creek 85 ft 9 years of Zeeman data. Distance ~535 pc Bower, Sandstrom, Goldston. in prep. Starlight Polarization - PowerPoint PPT Presentation
Transcript of GBT Measurements of the Zeeman Effect in the Eridanus/Orion Region
UC Berkeley
GBT Measurements of the Zeeman Effect in the Eridanus/Orion Region
Tim Robishaw
Carl Heiles
The Orion Molecular Cloud Complex
Heiles 1997
Hat Creek 85 ft
9 years of Zeeman data
Distance ~535 pcBower, Sandstrom, Goldston
in prep.
Starlight Polarization Orientations
Breger 1976, Vrba et al. 1988
Starlight Polarization Orientations
Breger 1976, Vrba et al. 1988
The GBT Is a Zeeman Machine!
Off-Axis DesignMinimizes Blockage
Minimizes Sidelobes!!
The GBT Is a Zeeman Machine!
The GBT Is a Zeeman Machine!
Verschuur’s Indictment
1993 BAAS 1821993 BAAS 1831995 ApJ 451: 6241995 ApJ 451: 645
Verschuur’s Indictment
Verschuur’s Indictment
3 hours
The GBTHat Creek85 foot
3 hours
OH
OH
Summary• The GBT can be used as a Zeeman detector• Apparent HI self-absorption samples the
molecular component of the filament• LOS B field measured in emission changes sign
across axis of filament– Detections consistent with previous HI emission
measurements: they were reliable!
• Field reverses within central half-degree of filament (~ 4.5 pc)
• Highest resolution data for modeling of helical magnetic field structure
