The Effect of Noise and Finite Sampling on the Line Profile Variations of m = 0 Modes

Extract

Figure 1 is of the same form as Fig. 3 in Schrijvers et al. (1997): the upper part of each panel is the amplitude of the variation across the line at the mode frequency and the lower part is the phase shift of these two components across the line (in units of Φ). The parameters {V_avg, k, Ω/ω⁰, W} were chosen to have values representative of the δ Scuti star 4 CVn. Each panel in this array of plots has m=0, with a value of ∓ of 0, 1, or 2, and an inclination angle θ_i between 10° and 80°. In order to generate the synthetic line profiles, we use sampling times taken from the last week of the 1996 δ Scuti campaign on 4 CVn, and we assume that the signal-to-noise ratio of the spectrum is 250.