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Author Zhang, Han ♦ Telesco, Charles M. ♦ Pantin, Eric ♦ Barnes, Peter ♦ Hoang, Thiem ♦ Li, Aigen ♦ Wright, Christopher M. ♦ Li, Dan
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ASTROPHYSICS ♦ COMPARATIVE EVALUATIONS ♦ DETECTION ♦ DUSTS ♦ EMISSION ♦ MAGNETIC FIELDS ♦ MESONS ♦ NEBULAE ♦ PARAMAGNETISM ♦ POLARIZATION ♦ POLYCYCLIC AROMATIC HYDROCARBONS ♦ RELAXATION ♦ STARS
Abstract Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in astrophysical environments, as revealed by their pronounced emission features at 3.3, 6.2, 7.7, 8.6, 11.3, and 12.7 μ m commonly ascribed to the C–H and C–C vibrational modes. Although these features have long been predicted to be polarized, previous searches for PAH polarization led to null or, at best, tentative detections. Here we report the definite detection of polarized PAH emission at 11.3 μ m in the nebula associated with the Herbig Be star MWC 1080. We measure a polarization degree of 1.9% ± 0.2%, which is unexpectedly high compared to models. This poses a challenge in the current understanding of the alignment of PAHs, which is required to polarize the PAH emission but thought to be substantially suppressed. PAH alignment with a magnetic field via a resonance paramagnetic relaxation process may account for such a high level of polarization.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2017-07-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 844
Issue Number 1


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