Line profiles from a NS with M′ = 1.4 M_⊙, R_e = 10 km rotating at 700 Hz, and seen by a distant observer at inclination i = 20°. The line profiles for a spherical NS with R = R_e and for an oblate NS shape both with Schwarzschild exterior metric are shown by the black and blue curves, respectively. Accounting for frame dragging and quadrupole moment gives the profile shown by the red curve. The line obtained with a quadrupole moment artificially increased by a factor of 4 above that given by Eq. (A.9) is shown by the dashed red curve. Compare to Fig. 5 in Nättilä & Pihajoki (2018).