ASTRONOMY 402T – Spring 2018
Problems for Tutorial Week #8

PART A

 1. a) Why is it not straightforward to calculate total abundance ratios in an ionized nebula.

b) Explain the concept of the ionization correction factor.

c) If you wanted to make measurements to be able to directly calculate total abundance ratios, describe the kinds of observations would you have to make?

PART B

Measure the line intensities in your assigned planetary nebula with splot. Use ELSA to calculate diagnostics and abundances. Compare with published values. Bring all (organized!) output material with you.