Goodness-of-fits of distorted line profiles contaminated with artificial noise obtained in planet-free (dashed lines) and giant planet-bearing disk (solid lines) models versus the integration time for 20°, 40° and 60° inclinations, represented by blue, green and red colors, respectively. It is visible that for a reasonable signal-to-noise ratio, the planet-free models provide always fits with less confidence than the giant planet models, i.e the χ² is always larger. Moreover, the smaller the inclination angle, the larger the required minimal integration time (t_int > 3187   s, 1909   s and 2271   s for the 20°, 40° and 60° inclinations, respectively) to distinguish the planet-free and planet-bearing disk models.