SUBMILLIMETER POLARIZATION OF GALACTIC CLOUDS: A COMPARISON OF 350 {mu}m AND 850 {mu}m DATA

Journal Article · Wed Aug 01 04:00:00 EDT 2012 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/201/2/13· OSTI ID:22047686

Vaillancourt, John E ^[1]

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1. SOFIA Science Center, Universities Space Research Association, NASA Ames Research Center, Moffett Field, CA 94035 (United States)

The Hertz and SCUBA polarimeters, working at 350 {mu}m and 850 {mu}m, respectively, have measured the polarized emission in scores of Galactic clouds. Of the clouds in each data set, 17 were mapped by both instruments with good polarization signal-to-noise ratios. We present maps of each of these 17 clouds comparing the dual-wavelength polarization amplitudes and position angles at the same spatial locations. In total number of clouds compared, this is a four-fold increase over previous work. Across the entire data set real position angle differences are seen between wavelengths. While the distribution of {phi}(850)-{phi}(350) is centered near zero (near-equal angles), 64% of data points with high polarization signal-to-noise (P {>=} 3{sigma}{sub p}) have |{phi}(850)-{phi}(350)| > 10 Degree-Sign . Of those data with small changes in position angle ({<=}10 Degree-Sign ) the median ratio of the polarization amplitudes is P(850)/P(350) = 1.7 {+-} 0.6. This value is consistent with previous work performed on smaller samples and models that require mixtures of different grain properties and polarization efficiencies. Along with the polarization data we have also compiled the intensity data at both wavelengths; we find a trend of decreasing polarization with increasing 850-to-350 {mu}m intensity ratio. All the polarization and intensity data presented here (1699 points in total) are available in electronic format.

• OSTI ID: 22047686
• Journal Information: Astrophysical Journal, Supplement Series, Journal Name: Astrophysical Journal, Supplement Series Journal Issue: 2 Vol. 201; ISSN 0067-0049; ISSN APJSA2
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AMPLITUDES
ASTROPHYSICS
CLOUDS
COMPARATIVE EVALUATIONS
DUSTS
EFFICIENCY
EMISSION
FORMATES
MIXTURES
POLARIMETERS
POLARIMETRY
POLARIZATION
SIGNAL-TO-NOISE RATIO
WAVELENGTHS