Precise laboratory wavelengths of the Mg I and Mg II resonance transitions at 2853, 2803 and 2796 A

Abstract

Strong ultraviolet resonance transitions are observed routinely both in the Galactic interstellar medium and in quasar absorption systems. The quality of the astronomical spectroscopic data now available demands more precise laboratory rest wavelengths. Of particular interest is the accuracy with which one can constrain space–time variations in fundamental constants using quasar spectra. A recent analysis by Webb et al. of 25 quasar spectra using Mg and Fe transitions tentatively suggests that the fine‐structure constant was smaller at earlier epochs. To permit a check on this result, and to allow further more extensive investigations, we have carried out a new determination of the laboratory wavelengths of Mg i 2853 Å, Mg II 2796 Å and Mg II 2803 Å by high‐resolution Fourier transform spectroscopy. Our results for Mg II 2796 Å are consistent with the value measured independently by two other groups. To our knowledge, no previous measurements of comparable precision exist for Mg I 2853 Å and Mg II 2803 Å.

Using magnesium to maximize heat generated by reactive Al/Zr nanolaminates

“…Atomic absorption and emission spectroscopy confirm that Mg vaporizes during the reaction of Al-8Mg:Zr foils in air and in argon, as indicated by the sharp Mg atomic absorption peak appearing at 285 nm [57], 0.01 s after Al-8Mg:Zr samples are reacted in either environment ( Fig. 6a and b).…”

Accurate laboratory wavelengths of some ultraviolet lines of Cr, Zn and Ni relevant to time variations of the fine structure constant

“…In this paper we describe the results of experiments at both Imperial College (IC) and Lund University (LU) to measure accurately the wavelengths of these Zn, Cr and Ni lines, together with a confirmation at LU of the earlier measurements on Mg at IC (Pickering, Thorne & Webb, 1998). Although the measurements in the two laboratories were made independently, they used similar high resolution UV Fourier transform (FT) spectrometers, with hollow cathode lamps as light sources.…”

“…Table 1 also includes the Mg lines previously published from IC (Pickering, Thorne & Webb 1998). The LU measurements of these Mg lines agree within 1 mK, thus providing important confirmation.…”

Ab initioestimations of the isotope shift for the first three elements of the K isoelectronic sequence

“…We would like to apply the optimized GTO wave functions in the RCC calculation of the IS for Mg II, which has been estimated several times in literature for theoretical and as well as experimental endeavors [1,26,[32][33][34][35][36]. Mg II is a simple single valence system that has 11 electrons but has enough electrons for a correlation study.…”