An Introduction to Modern Astrophysics · Problem 9.24
The Interiors of Stars — Carroll & Ostlie
Physics — Astrophysics · equivalent-width-ellipse
Problem
Suppose that the shape of a spectral line is fit with one-half of an ellipse, such that the semimajor axis a is equal to the maximum depth of the line (let Fλ=0) and the minor axis 2b is equal to the maximum width of the line (where it joins the continuum). What is the equivalent width of this line? Hint: You may find Eq. (2.4) useful.