Effective Collision Strengths for O II
Abstract
Accurate electron collisional excitation strengths Omega, from 11 state Rmatrix calculations performed in LS pi coupling, are convoluted with a Maxwellian velocity distribution to obtain effective collision strengths T for a range of temperatures 5 x 10 exp 3 to 10 exp 6 K for electron excitation of singly ionized atomic oxygen. This work considers electron collisional excitation of the O II ion from the 1s2 2s2 2p3 (4S ex p 0) to the 1s2 2s2 2p3 (2D exp 0), 2P exp 0) and to the higher lying 1s2 2s2 p4 (4P exp e) and 1s2 2s2 2p2 3s (4p expe) states. In addition, we consider the 1s2 2s2 2p3 (2D exp 0) to 1s2 2s2 2p3 (2p exp 0) transition. Comparison with existing values in the literature indicates improved results for the effective collision strengths at all temperatures.
 Publication:

The Astrophysical Journal
 Pub Date:
 May 1993
 DOI:
 10.1086/172635
 Bibcode:
 1993ApJ...408..753M
 Keywords:

 Atomic Collisions;
 Forbidden Transitions;
 Molecular Excitation;
 Oxygen Ions;
 Collision Parameters;
 MaxwellBoltzmann Density Function;
 Atomic and Molecular Physics;
 ATOMIC DATA;
 ULTRAVIOLET: STARS