THE HANLE EFFECT OF THE HYDROGEN Ly{alpha} LINE FOR PROBING THE MAGNETISM OF THE SOLAR TRANSITION REGION

Journal Article · Thu Sep 01 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/738/1/L11· OSTI ID:21562444

Trujillo Bueno, Javier; Stepan, JirI ^[1]; Casini, Roberto ^[2]

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1. Instituto de Astrofisica de Canarias, 38205 La Laguna, Tenerife (Spain)
2. High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

We present some theoretical predictions concerning the amplitude and magnetic sensitivity of the linear-polarization signals produced by scattering processes in the hydrogen Ly{alpha} line of the solar transition region. To this end, we have calculated the atomic-level polarization (population imbalances and quantum coherences) induced by anisotropic radiation pumping in semiempirical and hydrodynamical models of the solar atmosphere, taking into account radiative transfer and the Hanle effect caused by the presence of organized and random magnetic fields. The line-center amplitudes of the emergent linear-polarization signals are found to vary typically between 0.1% and 1%, depending on the scattering geometry and the strength and orientation of the magnetic field. The results shown here encourage the development of UV polarimeters for sounding rockets and space telescopes with the aim of opening up a diagnostic window for magnetic field measurements in the upper chromosphere and transition region of the Sun.

• OSTI ID: 21562444
• Journal Information: Astrophysical Journal Letters, Vol. 738, Issue 1; Other Information: DOI: 10.1088/2041-8205/738/1/L11; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
AMPLITUDES
CHROMOSPHERE
FORECASTING
HYDROGEN
LYMAN LINES
MAGNETIC FIELDS
MAGNETISM
POLARIZATION
RADIANT HEAT TRANSFER
SCATTERING
ATMOSPHERES
ELEMENTS
ENERGY TRANSFER
HEAT TRANSFER
NONMETALS
SOLAR ATMOSPHERE
STELLAR ATMOSPHERES