Top row: variations of the square root of the CRB of logN as a function of the column density and the excitation temperature. Second and third row: correlation coefficients between efficient estimators of (Tex, logN), and (logN, σV) in the second and third rows. respectively (defined in Eqs. (23) and (24)). Bottom row: variations of functions of the opacities. Left: only 13CO(1− 0) is analyzed. Middle: only 13CO(2−1) is analyzed. Right: both 13CO(1−0) and 13CO(2− 1) are analyzed simultaneously. In (a) and (b) pixels in grey correspond to Tex and N values whichlead to singular Fisher matrices. For this analysis, σb = 100 mK, ΔV = 1.1 km s−1 and σV = 0.61 km s−1.
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.