In the spectrum of the galaxy, the hydrogen line λ = 656.3 nm is shifted to the red end of the spectrum by Δλ = 21.9 nm.
September 16, 2020 | Education
| In the spectrum of the galaxy, the hydrogen line λ = 656.3 nm is shifted to the red end of the spectrum by Δλ = 21.9 nm. Determine the speed of removal of the galaxy and the distance to it
z = Δλ / λ = 21.9 / 656.3 = 0.033369
v = c * z = H * r, where the Hubble constant H = 73 km / (s * MPc)
v = 300000 * 0.033369 = 10011 km / s
r = v / H = 10011/73 = 137 megaparsec
