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Author Moise, E. ♦ Raymond, J. ♦ Kuhn, J. R.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ BRIGHTNESS ♦ DUSTS ♦ HELIOSPHERE ♦ HELIUM ♦ HELIUM IONS ♦ PHOTONS ♦ SOLAR CORONA ♦ SOLAR WIND ♦ SUN ♦ ATMOSPHERES ♦ BOSONS ♦ CHARGED PARTICLES ♦ ELEMENTARY PARTICLES ♦ ELEMENTS ♦ FLUIDS ♦ GASES ♦ IONS ♦ MAIN SEQUENCE STARS ♦ MASSLESS PARTICLES ♦ NONMETALS ♦ OPTICAL PROPERTIES ♦ PHYSICAL PROPERTIES ♦ RARE GASES ♦ SOLAR ACTIVITY ♦ SOLAR ATMOSPHERE ♦ STARS ♦ STELLAR ACTIVITY ♦ STELLAR ATMOSPHERES ♦ STELLAR CORONAE ♦ STELLAR WINDS
Abstract Sensitive SOLARC imaging spectropolarimetric observations from Haleakala reveal a diffuse coronal surface brightness in the He I 1083 nm line. A series of observations suggests that this signal originates from an 'inner source' of neutral helium atoms in the solar corona. Here, we explore the possibility that this cold coronal component originates from helium ions that are neutralized by the near-Sun dust and subsequently excited to the metastable 1s2s {sup 3} S state, which then scatters photons from the solar disk. This picture suggests a deficit of coronal dust inside about 2-4 R{sub sun} in order to account for both the flat radial brightness distribution and the small velocity line width of the observations. We find a strong correlation between the polarized He brightness and coronal white light brightness that supports the argument that electronic collisional excitation of the metastable helium triplet level is responsible for our polarization signal.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2010-10-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 722
Issue Number 2


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