Erratum for: A&A 602, A111 (2017), https://doi.org/10.1051/0004-6361/201629507

We correct an error in Eq. (34) of Herenz & Wisotzki (2017), where we provided an estimate for the signal-to-noise ratio for an emission line that matches the 3D Gaussian filter template of LSDCat. The correct equation reads

$$\begin{array}{c}\hfill {S/N}_{x\prime ,y\prime ,z\prime }\approx \frac{1}{\sqrt{8{\pi }^{3/2}{\sigma }_z}{\sigma }_{\mathrm{G}}}\times \frac{F_{\mathrm{line}}}{\overline{\sigma }\mathrm{\Delta }\lambda },\end{array}$$(1)

that is, σ_G is not under the square root as presented in the paper. All previous steps that lead to this equation, that is, Eqs. (29)–(33), were correct.

As a consequence of this correction, the numerical value of the limiting flux in the MUSE HDF-S data at 7000 Å, given in Eq. (35) of our paper, was also incorrect. Inserting the given values (σ_G = 1.84 px, σ_z = 1.46, $\overline{\sigma }=1.42\times {10}^{-20}$ erg s⁻¹ cm⁻² Å⁻¹, Δλ = 1.2 Å, and S/N_det ≈ 8) into Eq. (1) delivers

$$\begin{array}{c}\hfill log{F}_{\mathrm{line}}[\mathrm{erg}{\mathrm{s}}^{-1}{\mathrm{cm}}^{-2}]\approx -17.69.\end{array}$$(2)

Therefore Fig. 3, where the theoretical limiting flux was compared with the results of a source insertion and recovery experiment, also needs to be corrected. The corrected version of Fig. 3 is shown here in Fig. 1. The match between the experiment and theoretical expectation in Fig. 1 is closer in comparison to what was originally presented, so parts of the discussion in the final paragraph of Sect. 3.2 are thus obsolete.

Fig. 1. Completeness curve fC(log F [erg s−1 cm−2 Å−1]) from a fake source insertion and recovery experiment on the MUSE HDF-S datacube at 5000 Å. The dotted vertical line shows the 50% completeness limit at log F [erg s−1 cm−2]= − 17.75 and the dashed vertical line shows the analytically approximated minimum line flux given in Eq. (2) as log Fline [erg s−1 cm−2] ≈ − 17.69 at which LSDCat is expected to detect emission line sources in this experiment.

References

© ESO 2021

All Figures

Fig. 1. Completeness curve fC(log F [erg s−1 cm−2 Å−1]) from a fake source insertion and recovery experiment on the MUSE HDF-S datacube at 5000 Å. The dotted vertical line shows the 50% completeness limit at log F [erg s−1 cm−2]= − 17.75 and the dashed vertical line shows the analytically approximated minimum line flux given in Eq. (2) as log Fline [erg s−1 cm−2] ≈ − 17.69 at which LSDCat is expected to detect emission line sources in this experiment.

In the text