Free Access

Fig. 4


Analysis of the empirical uncertainty for short-term repeat observations of vsini using order-sorting filter HR15N. Plot a) shows the variation of Evsini × (S/N)( [ vsini ] /C)2/ (1 + ( [ vsini ] /C)2)5/4 with S/N . The horizontal line indicates the value of parameter β in Eq. (3) fitted to the full dataset. Blue crosses show the estimated values β as a function of S/N corrected for the measured variation of β with Teff (see Sect. 4.4 and Table 3). Plot b) shows the variation of Evsini × S/N with vsini. The solid line show the relationship predicted using the theoretical value of C and the value of β from plot a). In plots a) and b) the y-axis shows an estimate of the standard deviation based on the MAD divided by 0.82 (for ν = 2, see Sect. 3.3). Plot c) shows the cumulative probability distribution (CDF) of the normalised uncertainty in vsini for short-term repeats. The red solid line shows results for measured data, the dashed line shows the cumulative distribution of a Gaussian with unit dispersion, and the diamond symbols show the cumulative distribution function for a Student’s t-distribution with ν = 2.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.