H-, He-like recombination spectra III: $n$-changing collisions in highly-excited Rydberg states and their impact on the radio, IR and optical recombination lines. (arXiv:1903.05730v1 [astro-ph.GA])

H-, He-like recombination spectra III: $n$-changing collisions in highly-excited Rydberg states and their impact on the radio, IR and optical recombination lines. (arXiv:1903.05730v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Guzman_F/0/1/0/all/0/1">F. Guzm&#xe1;n</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chatzikos_M/0/1/0/all/0/1">M. Chatzikos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hoof_P/0/1/0/all/0/1">P. A. M. van Hoof</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Balser_D/0/1/0/all/0/1">Dana S. Balser</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dehghanian_M/0/1/0/all/0/1">M. Dehghanian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Badnell_N/0/1/0/all/0/1">N. R. Badnell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ferland_G/0/1/0/all/0/1">G.J. Ferland</a>

At intermediate to high densities, electron (de-)excitation collisions are
the dominant process for populating or depopulating high Rydberg states. In
particular, the accurate knowledge of the energy changing ($n$-changing)
collisional rates is determinant for predicting the radio recombination spectra
of gaseous nebula. The different datasets present in the literature come either
from impact parameter calculations or semi-empirical fits and the rate
coefficients agree within a factor of two. We show in this paper that these
uncertainties cause errors lower than 5% in the emission of radio recombination
lines (RRL) of most ionized plasmas of typical nebulae. However, in special
circumstances where the transitions between Rydberg levels are amplified by
maser effects, the errors can increase up to 20%. We present simulations of the
optical depth and H$nalpha$ line emission of Active Galactic Nuclei (AGN)
Broad Line Regions (BLRs) and the Orion Nebula Blister to showcase our
findings.

At intermediate to high densities, electron (de-)excitation collisions are
the dominant process for populating or depopulating high Rydberg states. In
particular, the accurate knowledge of the energy changing ($n$-changing)
collisional rates is determinant for predicting the radio recombination spectra
of gaseous nebula. The different datasets present in the literature come either
from impact parameter calculations or semi-empirical fits and the rate
coefficients agree within a factor of two. We show in this paper that these
uncertainties cause errors lower than 5% in the emission of radio recombination
lines (RRL) of most ionized plasmas of typical nebulae. However, in special
circumstances where the transitions between Rydberg levels are amplified by
maser effects, the errors can increase up to 20%. We present simulations of the
optical depth and H$nalpha$ line emission of Active Galactic Nuclei (AGN)
Broad Line Regions (BLRs) and the Orion Nebula Blister to showcase our
findings.

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