(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The spectroscopic observation of an interstellar gas cloud shows emission lines H (λ=6563 A), Hβ λ=4862 A) e OI (λ=1304 A), each one with a gaussian profile of the kind:

[itex] g(\nu)=A e^[-\frac{(\nu-\nu_0)^2}{2\sigma^2}] [/itex]

Per Hα si osserva [itex]σ_{Hα} = 1.2 \times 10^{10} Hz[/itex].

Supposing that gas is in thermodynamic equilibrium at a temperature T, uniform in the whole cloud, determine:

1) the T value;

2) the [itex]σ_{OI}[/itex] value;

3) the Full Width at Half Maximum of the Hβ line.

2. Relevant equations

The Doppler broadening [itex]Δ\nu/\nu = v/c[/itex].

The Virial temperature: [itex] 1/2 m v^2 = 3/2 k T[/itex].

3. The attempt at a solution

Regarding only the first point, can I proceed with the above-mentioned formulas?

If yes, I find a temperature of T≈2500 K, that is an order of magnitude higher then the typical temperature of interstellar clouds...

If not (and this is), why not?

Thanks in advance :)

PS: I don't like this formulas editor et all :D

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# Homework Help: Gaussian emission lines

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