Issue |
A&A
Volume 552, April 2013
|
|
---|---|---|
Article Number | A33 | |
Number of page(s) | 3 | |
Section | Astrophysical processes | |
DOI | https://doi.org/10.1051/0004-6361/201220699 | |
Published online | 20 March 2013 |
Research Note
Excitation and deexcitation processes in atom-Rydberg atom collisions in helium-rich white dwarf atmospheres
1
University of Belgrade, Institute of physics,
PO Box 57,
11001
Belgrade,
Serbia
e-mail:
vlada@ipb.ac.rs
2
Institute Isaac Newton of Chile, Yugoslavia Branch, 11060
Belgrade,
Serbia
3
Astronomical Observatory, Volgina 7, 11060
Belgrade 74, Serbia
4
Observatoire de Paris, 92195
Meudon Cedex,
France
Received:
6
November
2012
Accepted:
14
February
2013
We aim to show the importance of non-elastic excitation and deexcitation processes in He∗(n) + He(1s2) collisions with the principal quantum number n ≥ 3 for helium-rich white dwarf atmospheres. We compare the efficiencies of these processes with those of the known non-elastic electron-He∗(n) atom processes in the atmospheres of some DB white dwarfs. We show that in significant parts of the considered atmospheres, which contain weakly ionized layers (the ionization degree ≲10-3), the influence of the studied atom-Rydberg atom processes on excited helium atom populations is dominant or at least comparable to the influence of the concurrent electron-He∗(n)-atom processes.
Key words: atomic processes / astrochemistry / stars: atmospheres / white dwarfs
© ESO, 2013
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.