deletions | additions       diff --git a/untitled.tex b/untitled.tex  index d48b31a..1d66b9b 100644  --- a/untitled.tex  +++ b/untitled.tex 
...
\item Clumping   \end{itemize}  Massive stars are thought to be important in reionization of the early universe, and also represent an important force in galaxy evolution through both their supernovae and strong, radiation-driven winds. These dense winds, driven by line scattering, can impact massive star evolution, removing in some cases more than 10\% of an O star's mass over its lifetime. The impact of metallicity on mass loss is especially interesting, since reionization and galaxy evolution involve massive stars in widely varying -- and often very low metal --  environments. Castor, Abbot, \& Klein (1975) gave a first quantitative description of this line driving by assuming a smooth, steady-state wind, and extensions of this theory have had success explaining a variety of wind properties, including the dependence of mass loss rate on metal content (cite). There is now substantial empirical evidence (cite Evansberg, Puls, Cohen, Njarro, Sundqvist, Bouret; see Sundqvist 2013) suggesting that these winds are not smooth, but instead substantially "clumped". Theory also predicts that the line driving of these winds has an intrinsic instability, the line-deshadowing instability (LDI), which would generate clumped structure. This has important implications on commonly-used mass loss rate diagnostics like H-$\alpha$, which typically assume a smooth wind. Recent work by Mokiem (2007) gave an empirical power law relation between mass-loss rate $\dot{M}$ and metal content $Z$, with $\dot{M} \propto Z^m$ and $m = 0.83 \pm 0.16$, consistent with theoretical predictions by Vink et al. 2001. This relation relied on an assumption that clumping did not change with metallicity in these winds.