Manganese Abundances in Cluster and Field Stars

We have derived Mn abundances for more than 200 stars in 19 globularclusters. In addition, Mn abundance determinations have been made for acomparable number of halo field and disk stars possessing an overlapping rangeof metallicities and stellar parameters. Our primary data set was comprised ofhigh resolution spectra previously acquired at the McDonald, Lick and KeckObservatories. To enlarge our data pool, we acquired globular and open clusterspectra from several other investigators. Data were analyzed using syntheticspectra of the 6000 \AA Mn I triplet. Hyperfine structure parameters wereincluded in the synthetic spectra computations. Our analysis shows that for themetallicity range $-0.7>$[Fe/H]$>$$-$2.7 stars of 19 globular clusters have a amean relative abundance of $<$[Mn/Fe]$>$= $-0.37\pm0.01$ ($\sigma$ = 0.10), avalue in agreement with that of the field stars: $<$[Mn/Fe]$>$= $-0.36\pm0.01$($\sigma$ = 0.08). Despite the 2 orders of magnitude span in metallicity, the$<$[Mn/Fe]$>$ ratio remains constant in both stellar populations. Our Mnabundance data indicate that there is no appreciable variation in the relativenucleosynthetic contribution from massive stars that undergo core-collapsesupernovae and thus, no significant change of the associated initial massfunction in the specified metallicity range.Comment: 43 Pages, 7 Figures; amended typo