Jan 7, 2017 · This is an excellent question. Think about the way in which emission happens. $\text{H}\alpha$ emission happens when an electron makes a transition from the third energy level to the second, emitting a photon in the process with the energy equivalent to the difference of the energies of the two states, roughly $1.9\text{ eV}$.

I know, for instance, that if you use the lines [OIII]4363 and [OIII]5007 the electron temperature can be computed. In the same way, the ratio between [OII]3729 and [OII]3726 provides an estimation of electronic density. Actually, I also know that, for the case of [OIII], its metastable excited states are relatively separated.

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Jan 14, 2015 · Measuring a line strength ratio is important because the ratio will be independent of the abundance of OIII. The ratio will depend on electron density, providing the electron density is $>10^{5}\ cm^{-3}$, and temperature (at lower densities, the …

Jan 8, 2025 · Amateur astrophotographer here. I've been researching like crazy to understand OIII emissions. I "get" the forbidden lines and all. What I don't understand is why electrons can go into the 1 D 2 as well as the 3 P 2 state. Though I've read Hund's rule does not always apply to excited atoms, it seems it often does.

Jul 30, 2018 · The "double Lambda", in the example you provided, is a 'half doublet'. A doublet for that element would be OIII]λλ1661,1666 another example would be SiIII]λλ1882,1892. One paper where this is discussed is: "CIII] Emission in Star-forming Galaxies at z ~ 1" (Mar 4 2017), by Xinnan Du, Alice E. Shapley, Crystal L. Martin, and Alison L. Coil ...

May 8, 2023 · To those who aren’t aware, an OSC narrowband filter is a filter with multiple band passes, for different emission lines. These can include a combination of Hα, Hβ, OIII, SII, and other emission lines. They are meant for OSC cameras, or …

Feb 27, 2016 · The OIII filter is a narrowband filter, meaning it cuts all light except at a very narrow wavelength range from ionized oxygen. Very often OIII filters make the difference between being able to see an object and not being able to see it, even from very dark skies.

Generally there may be some line ratio between the two lines. If H$\\alpha$ is strong, it is quite possible we can see H$_\\beta$ too. Is it possible we can see H$_\\beta$, but can not see H$_\\alph...

Mar 3, 2014 · It is a good catalog to begin with, but bsc5p is observational data which may be affected by many different factors. We do not know whether an OIII star's 'typical' mag. How to know an OIII star's theoretical absolute magnitude? $\endgroup$ –