Other
Scientific paper
Oct 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998phdt........26w&link_type=abstract
Thesis (PHD). THE UNIVERSITY OF TEXAS AT AUSTIN , Source DAI-B 59/09, p. 4875, Mar 1999, 116 pages.
Other
1
Scientific paper
Hg II abundances have been determined for 42 mercury-manganese (HgMn) stars by fitting synthetic spectra to observed spectra of the 3984 A Hg II line. Nine of the stars had lines sharp enough to allow their Hg isotopic abundance mixes to be found. The Hg abundance is reported for more HgMn stars here than in any other single work. No correlation was found between Hg II abundance and Teff or the central wavelength of the 3984 A line. There may be a weak correlation between logg and the derived Hg II abundance. The mean central wavelength of the 3984 A line, an indicator of the Hg isotopic mix, is loosely correlated with T eff: stars with primarily heavy Hg isotopes tend to be cooler. I find that there is no evidence that any of the HgMn stars have 196Hg or 198Hg. For the sharp-lined stars, the 204Hg abundance decreases with increasing T eff. No correlation is seen between mean central wavelength and logg or between vsini and A(Hg) or the central wavelength of the 3984 A line. The 4358 A Hg I line was measured at high spectral resolution for seven HgMn stars. The isotopic shifts are too small and the hyperfine components are too weak to allow unambiguous isotopic abundance ratios to be found. Hg I abundances match Hg II abundances fairly well. Some Hg isotopic mixtures are difficult to explain using only diffusion. HR 7245 has approximately equal abundances of 199Hg, 200Hg, 202Hg, and 204Hg but very little 201Hg and 11 Per has Hg that is mostly 199Hg and 204Hg. My calculations show that the effect of hyperfine splitting of the 201Hg line on diffusion may partly explain the Hg isotopic mix found in HR 7245, but I found no explanation for that of 11 Per. These were the first very high resolution measurements of the 3984 A line for HR 7245 and 11 Per. Although diffusion may be acting in HgMn stars, there must be one or more other mechanisms acting to produce the abundances seen, or our understanding of diffusion is lacking on some important point.
No associations
LandOfFree
Mercury Elemental and Isotopic Abundances in Mercury-Manganese Stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Mercury Elemental and Isotopic Abundances in Mercury-Manganese Stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mercury Elemental and Isotopic Abundances in Mercury-Manganese Stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1100651