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Recently Alexander and Gulyaev have suggested that the apparent decrease inimpact broadening of radio recombination lines seen at high principal quantumnumber n may be a product of the data reduction process, possibly resultingfrom the presence of noise on the telescope spectra that is not present on thecalculated comparison spectra. This is an interesting proposal. However, thereare serious problems with their analysis that need to be pointed out. Perhapsthe most important of these is the fact that for principal quantum numbersbelow n = 200, where the widths are not in question, their processed generatedprofile widths do not fit the widths of the processed lines obtained at thetelescope. After processing, the halfwidths of the generated and telescopeprofiles must agree below n = 200 if we are to believe that the processedgenerated linewidths above n = 200 are meaningful. Theirs do not. Furthermore,we find that after applying the linewidth reduction factors found by Alexanderand Gulyaev for their noise added profiles to our generated profiles tosimulate their noise adding effect, the processed widths we obtain still do notcome close to explaining the narrowing seen in the telescope lines for n valuesin the range 200 < n < 250. It is concluded that what is needed to solve thismystery is a completely new approach using a different observing techniqueinstead of simply a further manipulation of the frequency-switched data.

More on the Narrowing of Impact Broadened Radio Recombination Lines at High Principal Quantum Number