Details

Autor(en) / Beteiligte

• Zangrilli, L
• Poletto, G
• Nicolosi, P
• Noci, G

Titel

Lyman [alpha] intensities in a polar coronal hole from a 2D model

Ist Teil von

• Advances in space research, 2002-01, Vol.30 (3), p.523-528

Erscheinungsjahr

2002

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• We simulate the coronal H I Lyman [alpha] intensity for heliocentric distances between 1.5 and 2.5 R sub([middle dot in circle]), and latitudes between 90 degree (North pole) and 30 degree , making use of a 2D semiempirical coronal hole model. Observations are made with the UltraViolet Coronagraph Spectrometer (UVCS) on board the ESA-NASA solar satellite SOHO (SOlar and Heliospheric Observatory). Model electron densities are derived from the collisional part of the O VI [lambda]1037.6 Aa line and the proton outflow speed is calculated from mass flux conservation along the magnetic field lines. The expansion factor and the direction of the magnetic flux tubes have been derived by adopting a simple analytical magnetic field configuration. The intensities of the Ly [alpha] line predicted by the model are compared with the observed intensities.