Download SOFIA Polarimetry: Recent Musings

SOFIA Polarimetry:
Recent Musings
C. Darren Dowell
JPL/Caltech
2007 August 14
SOFIA 1st Generation Instruments
SOFIA 1st Generation Instruments
SOFIA Polarization Science
Magnetic Field Strengths; Turbulence
Class 0/I
Class II
Galaxies
Polarization spectrum of GMCs
What about tenuous clouds? Starless environments?
SOFIA Polarization Science
Magnetic Field Strengths; Turbulence
Class 0/I
Class II
Galaxies
Polarization spectrum of GMCs
What about tenuous clouds? Starless environments?
SOFIA Polarimetry Meeting
Chicago area, July 2007
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Participants: (S. Casey), J. Cho, D. Chuss, R.
Crutcher, J. Dotson, D. Dowell, D. FalcetaGoncalves, P. Frisch, A. Harper, F. Heitsch, R.
Hildebrand, T. Hoang, T. Jones, L. Kirby, M.
Krejny, A. Lazarian, R. Loewenstein, L. Looney,
(H. Moseley), G. Novak, (C. Packham), R.
Pernic, D. Sandford, (M. Savage), J. Vaillancourt,
(M. Werner), J. Wirth, G. Wolf-Chase
Representing: Ames, Caltech, Chicago, Florida,
Goddard, Illinois, JPL, S. Korea, Michigan,
Minnesota, Northwestern, Wisconsin
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Unanimous support for an interim
solution: polarimeter for HAWC
HAWC polarimeter options:
– cold, spinning half-wave plates at
pupil wheel
– warm variable-delay polarization
modulator in foreoptics
•
Design principles:
– goal of facility observing mode
– switch from camera mode to
polarization mode without opening
cryostat
– air worthiness approval
– parallel development
(JPL/Caltech?); outside HAWC
critical path
– integrate with HAWC after HAWC
is ready for SOFIA
HAWC Polarimeter Options
spinning half-wave plates
HAWC Polarimeter Options
reflective modulator
HAWC Polarimeter Options
spinning half-wave plates
• estimated cost for either option: $1M
Excellent Sensitivity
Paths to SOFIA Polarimetry
• Polarimetry will be well-represented at August
SPIE session “SOFIA Instrumentation”
– Chris Packham: mid-IR (based on FORCAST)
– John Vaillancourt: far-IR (HAWCHale)
• Seed funding possibilities:
– JPL R&D fund: $200k?
– NASA ROSES: ???
• SOFIA first-generation upgrade program?
• SOFIA second generation instrument program
– Hale (“SuperHAWC”): 5000 pixel far-IR camera /
polarimeter, advanced mapping capability (entire GMCs)