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Originally Posted by madbadgalaxyman
An interesting and strongly-physical perspective, Steven.
Sounds like it comes from someone who has had intensive physics training, unlike me (my approach, all my life, has been to learn only the physics & maths that is absolutely necessary for me to understand the astronomy I happen to be studying, but no more than that)
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While Quantum mechanics (QM) is taught at an undergraduate level in Physics and at a more introductory level in Chemistry, it is fact a branch of Applied Mathematics. When taught as an Applied Maths subject one goes far deeper into the theory due to the mathematical nature of QM.
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Q. All the astrophysics books talk about 'collisional excitation' (which sounds like a very exciting type of excitation!) of the OIII ion, but they never mention if there are any transitions of this atom that can be set off by energy that is provided to the atom by photons (that is, by electromagnetic radiation).
Can OIII be excited by a photon?
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Most definitely. In fact the primary mechanism for the observation of OIII lines in the spectra of emission nebulae is the absorption of electromagnetic energy from stars into the surrounding gas.
Photons are absorbed by oxygen resulting in ionization.
Electrons are recaptured by the ionized oxygen. When oxygen returns to its ground state photons are re-emitted at energies corresponding to the OIII frequencies at 495.9 and 500.7 nm.
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I am buying a copy of the aforementioned book "Atomic Astrophysics and Spectroscopy", because I find that most astrophysics textbooks only give a sketch of physical processes in ionized gas regions.
One book that I do use is "Physics of the Interstellar and Intergalactic Medium", (2011), by Bruce T. Draine, (Princeton University Press)(ISBN: 9780691122144).
I find this solidly graduate-level text to be heavy going, for the most part, and I have to keep referring back to physics textbooks when I use it, because I only have a unit or three of tertiary-level physics.
[ A more famous book is Osterbrock & Ferland (2005) "Astrophysics of Gaseous Nebulae and Active Galactic Nuclei."]
I find that while I do own lots of easier books about the ISM, I am still forced to tiptoe through graduate level texts, as the interstellar medium is so remarkable in its complexity!
There seem to be a lot of high-level ISM books coming out, of late (by: A.G.G.M Tielens, Sun Kwok, the Draine book that I mentioned, etc). I wonder if anyone is reading them?
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I need to brush upon my astrophysics, I'll keep an eye out on these publications.
Regards
Steven