Derivations Flashcards
background subtraction errors
N(s+b) = N(s) + N(b) = total counts from source plus background
N(s) = N(s+b) - N(b)
= [N(s) + N(b)] -N(b)
σ^2(S) = N(s+b) + N(b)
= N(s) + 2N(b)
N(s) =
rate x Δt
where Δt = integration
A(jI) =
einstein coefficient
I(jI) =
photon emission rate per unit volume
line broadening derivation
[λ-λ(0)]/λ(0) = v/c
φ(th) ∝ exp(-mv^2/2kT)
substitute for v
= φ(0) exp(-([λ-λ(0)]/Δλ(th)^2)
[Δλ(th)/λ(0)]^2 = 2kT/mc^2 = (v(th)/c)^2
v(TOT)^2 = v(th)^2 +v(turb)^2
φ(TOT) = φ(th) * φ(turb)
[Δλ(turb)/λ(0)]^2 = [v(turb)/c]^2
convolution theorem
fourier of φ(TOT) ∝ e^-π^2(Δλ(th)^2+Δλ(turb)^2)s^2
take the inverse Fourier transform
Δλ(TOT)^2 = Δλ(th)^2 + Δλ(turb)^2
Δλ(TOT)^2 = λ(0)^2 v(TOT)^2/c^2
v(TOT)^2 = v(th)^2 +v(turb)^2