... Archives . ... This week, we explore the special case of optically thin emission from low-density and high-temperature plasma, and consider the component factors that determine the line intensity. ... The ion balance i(T e ,Z,I)=N Z,I /N Z is strongly variable, as is the so-called emission measure, EM = N e 2 dV , which btw is also a function of T e . ... Tags: abundance , emission , emission measure , emissivity , EotW , Equation , Equation of the Week , flux , ion balance , line . ... Chandra Blog...