Experimental Investigation of the Hyperfine Structure and Theoretical Studies of the Even Configurations of Sc I

Abstract

Optogalvanic laser spectroscopy has been applied to measure the hyperfine structure of 13 spectral lines of Sc I in the wavelength range from 645 to 780 nm. Experimental magnetic dipole hyperfine structure constants A of the isotope 45 Sc have been determined for three levels of even and ten levels of odd parity. For six of these levels the A constants have been measured for the first time. For two further levels the A constants have already been measured but discrepancies between our values and the previous ones are found and discussed. With the new experimental results a parametric analysis of the magnetic dipole hyperfine structure has been performed for the even configuration 3d 2 4s and a very high value for the contact parameter a 10 3d has been found. Additionally, the experimental results for the other even levels are discussed.

The elemental composition of the Sun

“…Ertmer & Hofer (1976) also presented ABMR data for the ( 3 F)4s 4 F 3/2, 9/2 levels. We note that optogalvanic spectroscopy (OGS) data presented by Singh et al (1991) for the ( 1 D)4s 2 D 3/2, 5/2 levels are not reliable, due to errors in their relative intensity formula pointed out by Aboussaïd et al (1996), and confirmed by Bieron et al (2002) and Başar et al (2004 Work on the HFS of Sc  is rather less common. The most recent and accurate data that we could find come from Villemoes et al (1992) and Mansour et al (1989), the latter of whom employed the ultra-high-resolution ABMR technique.…”

“…In some cases Aboussaïd et al (1996) provide more than one measurement for a given level; we take the average of these measurements, weighted according to their uncertainties. For the ( 3 F)4s 2 F 5/2, 7/2 levels, theoretical results presented by Başar et al (2004) are the only data available. Ertmer & Hofer (1976) also presented ABMR data for the ( 3 F)4s 4 F 3/2, 9/2 levels.…”

Atomic data for the Gaia-ESO Survey

“…ABMR data were also presented by Ertmer & Hofer (1976) and Zeiske et al (1976) for the ( 3 F)4s 4 F 3/2,5/2,7/2,9/2 levels, which we employ. For several others, including the ( 3 F)4s 2 F 5/2,7/2 levels, the only source of data are the calculations published by Başar et al (2004). The high-excitation levels are represented by the theoretical predictions by Öztürk et al (2007).…”

“…Den Hartog et al (2006) observed partially resolved isotopic and hyperfine structure in the profiles for a few of the Gd ii lines in their highest resolution FTS data, and Wickliffe et al (2000) noticed partially resolved structure for many of the Dy ii lines in their FTS spectra. Başar et al (2004) 1.865 -0.0008 0.0000 4s 2 F Başar et al 20041.996 -0.0115 0.0000 4p 2 D Başar et al (2004) 3.619 0.0029 0.0000 4p 4 G Başar et al (2004) 3.633 0.0015 0.0000 4p 4 G Başar et al (2004) 3.878 0.0019 0.0000 4p 4 F Öztürk et al (2007) 4.110 0.0034 0.0000 4p 2 G Öztürk et al (2007) 4.111 0.0071 0.0000 4p 2 F Öztürk et al (2007) 4.179 0.0015 0.0000 4p 2 D Başar et al (2004) Article number, page 65 of 78…”

Atomic Data Needs in Astrophysics: The Galactic Center “Scandium Mystery”

“…In the work of van Deelen [12], synthetic model spectra of Sc I hyperfine structure (HFS) multiplets were constructed and fitted to experimentally measured spectra. The results were compared to similar results from the literature [16][17][18][19][20][21][22][23], and investigations were initiated to examine the significant differences more closely. The work of van Deelen [12] can be considered the most recent and accurate compilation of Sc I HFS data for the near infrared wavelength region.…”