THE SUBMILLIMETER POLARIZATION SPECTRUM OF M17

Journal Article · Sat Aug 10 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/773/1/29· OSTI ID:22140284

Lingzhen, Zeng; Jimenez-Serra, Izaskun ^[1]; Bennett, Charles L. ^[2]; Chapman, Nicholas L.; Novak, Giles ^[3]; Chuss, David T. ^[4]

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1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
2. Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)
3. Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States)
4. Observational Cosmology Laboratory, NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)

We present 450 {mu}m polarimetric observations of the M17 molecular cloud obtained with the SHARP polarimeter at the Caltech Submillimeter Observatory. Across the observed region, the magnetic field orientation is consistent with previous submillimeter and far-infrared polarization measurements. Our observations are centered on a region of the molecular cloud that has been compressed by stellar winds from a cluster of OB stars. We have compared these new data with previous 350 {mu}m polarimetry and find an anti-correlation between the 450 and 350 {mu}m polarization magnitude ratio and the ratio of 21 cm to 450 {mu}m intensity. The polarization ratio is lower near the east end of the studied region where the cloud is exposed to stellar winds and radiation. At the west end of the region, the polarization ratio is higher. We interpret the varying polarization spectrum as evidence supporting the radiative alignment torque model for grain alignment, implying higher alignment efficiency in the region that is exposed to a higher anisotropic radiation field.

• OSTI ID: 22140284
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 773; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ALIGNMENT
ANISOTROPY
COMPARATIVE EVALUATIONS
CORRELATIONS
EFFICIENCY
MAGNETIC FIELDS
POLARIMETERS
POLARIMETRY
POLARIZATION
SPECTRA
STARS
STELLAR WINDS