(a) Using Eq. (9.63) and neglecting turbulence, estimate the full width at half-maximum of the hydrogen Hα absorption line due to random thermal motions in the Sun's photosphere. Assume that the temperature is the Sun's effective temperature.
(b) Using Hα redshift data for solar granulation, estimate the full width at half-maximum when convective turbulent motions are included with thermal motions.
(c) What is the ratio of vturb2 to 2kT/m?
(d) Determine the relative change in the full width at half-maximum due to Doppler broadening when turbulence is included. Does turbulence make a significant contribution to (Δλ)1/2 in the solar photosphere?