EDP Sciences
Free access
Volume 419, Number 1, May III 2004
Page(s) 1 - 5
Section Astrophysical processes
DOI http://dx.doi.org/10.1051/0004-6361:20040040

A&A 419, 1-5 (2004)
DOI: 10.1051/0004-6361:20040040

$\mathsf{H^+}$ + H(1s) collisions at intermediate impact velocities as a new source of UV and VUV radiation

A. A. Mihajlov1, 2, A. M. Ermolaev3 and Lj. M. Ignjatovic1, 2

1  Institute of Physics, PO Box 57, 11001 Belgrade, Yugoslavia
2  Institute Isaac Newton of Chile, Yugoslavia Branch, Belgrade, Serbia, Yugoslavia
3  Dept. of Theor. Phys., Campus Plaine, CP 231 Boulevard du Trioumphe, 1050 Bruxelles, Belgium

(Received 24 January 2003 / Accepted 15 January 2004 )

The process of radiative charge exchange in ${\rm H^+ + H}(1s)$ collisions at the intermediate ion-atom impact velocities are treated in this work as a source of continuous EM emission in the UV and VUV range. The spectral intensity of this emission is determined, within the semiclassical method developed in previous works, for the ion-atom impact energies (in the center of mass reference frame) from 0.5 keV to 12.5 keV. The results obtained show that the spectral intensity of the examined EM emission increases for several orders of magnitude when passing from the visible to the VUV range of wavelength, and that the position of the maximum of this spectral intesity drifts with increase of collision energy from  $\lambda \cong$ 51 nm to  $\lambda \cong$ 18 nm. These results imply that considered radiation processes may be of interest in astrophysics as a new sources of continuous short-wave EM emission.

Key words: atomic processes -- radiation mechanisms: general -- stars: atmospheres

Offprint request: A. A. Mihajlov, mihajlov@phy.bg.ac.yu

© ESO 2004