Free Access

Fig. 4


Simulation of the expected signal-to-noise ratio for emission Lyα line and continumm with a 52 h integration with FORS2. From top to bottom: the two dimensional spectra of the sky and RMS map are shown as an example and guidance for the eye. Simulated signal to noise 2d-spectra of line emission (snapshot) and continuum emissions are shown with an indicated line flux and magnitude at the (flat) continuum on the right. It is clear that the S/N is lower where the sky lines are stronger. In the bottom part the S/N of the Lyα feature versus redshift (solid black line) and the continuum (red dotted line) are reported for the case of GDS_1408. The transparent grey region marks the zMIN<z<zMAX interval; see text for more details. Grey horizontal dotted lines mark S/N = 1.5 and 3.0.

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.