Iron abundance ratios dependence

Abundance ratios and the Iron Mass to Light Ratio (IMLR) are good tests for the evolution of galaxies in clusters since they do not depend on the total cluster gas mass. The IMLR is defined as (Renzini et al. 1993) ... 

Iron isotope data in the literature have been reported in both standard 5 notation (parts per 10 ), and s notation (parts per lO ), and workers have reported data in terms of Te/ Fe, Te/ Fe, or Fe/ Fe ratios. The low abundance of Fe limits its usefulness in describing mass-dependent variations, although Fe may be important for evaluating non-mass dependent effects (e.g., Volkening and Papanastassiou 1989). In standard per mil notation, the 5 Fe and 5 Te values are most commonly defined as ... 

Figure 2.1 shows the dependence of element abundances on atomic number for the cosmos. In cosmochemistry, such abundances are always presented as a ratio— number of atoms of the respective element/10 atoms silicon—in order to eliminate the influence of the strongly varying concentrations of hydrogen and helium. The remarkable drop in abundance from atomic number 47 onward indicates the boundary between elements formed by nuclear fusion and those built up by subsequent neutron absorption reactions. Maxima are always related to especially high nuclear stability of the respective element (a typical example is the iron peak). 

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