\magnification=\magstep1


$$
B_{\lambda}(T) \quad = \quad 
          {   {2 h c^2 / {\lambda^5}}  \over 
              {e^{hc / {\lambda}kT} - 1 }     }
$$

$$
\epsilon \quad = \quad 6.8 \times 10^{-38} \thinspace
                      Z^2 n_e n_i \thinspace T^{-1/2} \thinspace
                      e^{-h \nu / k T} \thinspace
                      \bar{g}_{ff}  
                      \qquad  {\rm erg\ s^{-1}\ cm^{-3}\ Hz^{-1} }
$$


\bye
