On the formation of Mg II h and k lines in solar prominences

0429300 - ASÚ 2015 RIV FR eng J - Journal Article
Heinzel, Petr - Vial, J. C. - Anzer, U.
On the formation of Mg II h and k lines in solar prominences.
Astronomy & Astrophysics. Roč. 564, April (2014), A132/1-A132/10. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR GAP209/12/0906; GA ČR(CZ) GAP209/11/2463; GA ČR GA205/09/1705
Institutional support: RVO:67985815
Keywords : line: profiles * line: formation * Sun: filaments, prominences
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 4.378, year: 2014

We computed the Mg II h and k line profiles that are emergent from prominence-slab models and show their dependence on kinetic temperature, gas pressure, geometrical extension, and microturbulent velocity. By increasing the line opacity, significant departures from the complete frequency redistribution take place in the line wings. Models with a PCTR temperature structure show that Mg II becomes ionized to Mg III in the temperature range between roughly 15 000 and 30 000 K. Doppler dimming is significant for Mg II resonance lines. At the velocity 300 km s(-1), the line intensity decreases to about 20% of the value for static prominences. Finally, we demonstrate the role of Mg II h and k radiation losses on the prominence energy balance. Their dominant role is at lower pressures, while the losses due to hydrogen and Can dominate at higher pressures.
Permanent Link: http://hdl.handle.net/11104/0234460