Quote:
Originally Posted by troypiggo
Thanks for the reply, Bert. I wasn't aware that it was 50/50 for emission objects. I've always read about the strong Ha, but NII is seldom mentioned other than planetary nebulae in the places I've seen.
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Troy what people have been calling HA for many years is really HA and NII lumped together. If their filter was 5nm or greater in bandpass they would be recording both.
Below is a spectral graph of their relative emissions I assume for a mixture of 50:50 N and H as both these spectral lines come from the monatomic atoms not molecules as H2 and N2 exists on Earth. It is a bit more complicated than just two emission lines.
It is only in the vast emptiness between stars that atoms exist without forming molecules and really only interact with the odd passing electron only much later to have a photon from a nearby star ruin the relationship. This always results in a new photon emitted when the electron falls back into the proton. I am sure you would see a naked proton would be more likely to interact with an electron rather than another proton. To form molecules of even H2 you would need two protons and two electrons in the same place due to multiple random collisions. This very rarely happens in deep space.
All the other atomic species such as O and N and S and others will hang on to any electron/s and then start this same process as the naked proton or Hydrogen atom when the incoming photons have the energy to ionise them. It takes far more energy from the incident photon to ionise a large nucleus such as NII or OIII than a puny single proton which is the Hydrogen atom. Why the wavelengths and quanta are nearly the same is because the already accumulated electrons shield the larger nucleus of a O or N so the outer electron has a similar quantised energy difference.
For dust and gas to form into stars and a planetary system it all has to get very cold first so gravity will overcome the escape velocity of all the components be they atoms molecules or tiny bits of dust.
What fascinates me is that this is where we all came from! Uncountable atoms have interacted for billions of years so we can argue!!
I have not come very far from the ape at the Zoo that throws its own excrement at people he/I do not agree with!
For more see the FAQ at Astrodon.
Final note. When contemplating an image of a Super Nova Remnant. You are looking at an image of your real ancient ancestors!
Bert