An Introduction to Modern Astrophysics · Problem 12.8
Main-Sequence and Post-Main-Sequence Stellar Evolution — Carroll & Ostlie
Physics — Astrophysics · molecular-cloud-cooling
Problem
(a) Equations (12.10) and (12.11) illustrate a cooling mechanism for a molecular cloud accomplished through the excitation of oxygen atoms. Explain why the excitation of hydrogen rather than oxygen is not an effective cooling mechanism.
(b) Why are the temperatures of hot cores significantly greater than dense cores?