Talk:Megamaser

association with Seyfert 2, not Seyfert 1, implies AGN accretion tori are wide & flat ?
Inexpertly, Seyfert 2 galaxies are Seyfert 1 galaxies, but viewed "edge on" instead of "face on". However, megamasers are not observed, from "face on" Seyfert 1 galaxies. Since masing amplification derives from the optical depth, along the sightline to earth, of excited "pumped" molecules, perhaps the accretion tori of Seyfert galaxies are flat and wide, resembling a large washer, for a bolt or screw? Low flat wide accretion tori would have considerably more optical depth "edge on" than "face on", since the sightlines through the masing medium would be allot longer. So, perhaps the association of megamasers only with "edge on" Seyferts suggests something of the structure of their SMBH accretion disks? Moreover, the SMBH in "edge on" Seyferts resides directly behind (half of) the masing medium, and so might be a source of the "triggering" radio emissions? 66.235.38.214 (talk) 04:34, 26 December 2012 (UTC)
 * According to info from this article, the mean-free path between collisions, for OH molecules, in megamasing media, is λ = 1/nσ ~ 1AU. And, so, the mean-free time between collisions is τ = λ/CS ~ 10yr.  According to Advanced Astrophysics by Neb Duric, the rotational & vibrational excitation modes responsible for masing-frequency emissions are meta-stable, having lifetimes of ~10Myr.  Ipso facto, OH molecules in dense warm megamasing media could collide millions of times, and become collisionally excited, before ever spontaneously naturally de-exciting.  So collisional excitation may be an easy explanation, for the "pumping" process — millions of collisional encounters, with other particles, perpetually "pump" energy into rotational & vibrational excited states, with nearly no spontaneous decays occurring, so "setting" the entire masing medium into an excited stated, "waiting" to be triggered, at appropriate radio-to-microwave frequencies?  If so, then perhaps a professional could improve the Wikipedia article, with appropriate references & citations? 66.235.38.214 (talk) 05:16, 26 December 2012 (UTC)