2006/09/06 by Barbara Ercolano, P. J. Storey · 7 citations
Physics and Astronomy · #Ab initio #Advanced Chemical Physics Studies #Atomic and Molecular Physics #Atomic physics #Cold Atom Physics and Bose-Einstein Condensates #Emission spectrum #Hydrogen #Ion #Ionization #Photoionization #Physics #Spectral line #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10988.x
published as Mon.Not.Roy.Astron.Soc.372:1875-1878,2006 · 4 Pages, 1 Figure, Full version including electronic data tables availabe from http://hea-www.harvard.edu/~bercolano/data/MN-06-1037-MJ.tar.gz
arxiv created 2006/09/06 · openalex publication_date 2006/10/05 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present coefficients for the calculation of the continuous emission spectra of H i, He i and He ii due to electron–ion recombination. Coefficients are given for photon energies from the first ionization threshold for each ion to the n= 20 threshold of hydrogen (36.5 μm), and for temperatures 100 ≤ T≤ 105 K. The emission coefficients for He i are derived from accurate ab initio photoionization data. The coefficients are scaled in such a way that they may be interpolated by a simple scheme with uncertainties less than 1 per cent in the whole temperature and wavelength domain. The data are suitable for incorporation into photoionization/plasma codes and should aid with the interpretation of spectra from the very cold ionized gas phase inferred to exist in a number of gaseous clouds.