Such abundance studies also give hints that clusters are leaky

Such abundance studies also give hints that clusters are leaky

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Such abundance studies also give hints that clusters are leaky, especially for less massive (by and large cooler) examples. Fukazawa et al. (1998 PASJ 50, 187) show a very clear correlation between Si/Fe ratio and cluster temperature (shown below from their Fig. 3, from the ADS). Cooler clusters (shallower potential) have ratios characteristic of Sn Ia, while hot (massive) clusters have ratios close to the SN II production value. This suggests that only the most massive clusters have retained most of the ejecta from the initial burst of SN II, while most of the metals in poor clusters have come from more recent SN Ia. In a similar vein, comparison of gas temperatures to the expected virial temperature corresponding to the galaxies' velocity dispersion
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Unformatted text preview: shows that hotter clusters match well (the ratio, known as the β parameter, is close to unity) while for cooler clusters, the gas is too hot, indicating that the energy input from galactic winds (presumably driven by the enriching supernovae) is important compared to these shallower potentials. The presence of significant hot gas sets in somewhere in the group scale, as in the notorious NGC 2300 ROSAT report (Mulchaey et al. 1993 ApJL 404, L9). However, the detections of diffuse X-ray matter in groups are spotty, perhaps dependent on the galaxy types (being more likely when there are ellipticals present)....
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This note was uploaded on 11/10/2011 for the course AST AST1002 taught by Professor Emilyhoward during the Fall '10 term at Broward College.

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