Free Access
Erratum
This article is an erratum for:
[https://doi.org/10.1051/0004-6361/201834222]


Issue
A&A
Volume 643, November 2020
Article Number C1
Number of page(s) 2
Section Letters to the Editor
DOI https://doi.org/10.1051/0004-6361/201834222e
Published online 09 November 2020

The specific intensity (Eq. (5)) has not been correctly evaluated1. This affects the computation of the flux densities, whose correct trends are shown in the new versions of Figs. 3 and 4. We recovered the signal-to-noise ratios (S/Ns) quoted in the paper by assuming a magnetic field strength B0 larger by a factor of 2.74 − 4.20, 2.02 − 2.72, and 1.55 − 1.80 than originally assumed for models A, B, and C, respectively (the lower and upper values corresponding to κ  =  0.5 and κ  =  0.7, respectively). The conclusions of the paper are unaffected.

thumbnail Fig. 3.

Radial flux density profiles for the starless core models described in Sect. 5.1 (upper row) and for B68 and FeSt 1-457 (lower row, see Sect. 5.2). The observing frequency is shown in black at the top of each column, while numbers in the upper-right corner of each subplot represent the radius-averaged S/N for the two values of κ (0.5 and 0.7 for models A, B, C, and B68, and 0.68 and 0.88 for FeSt 1-457, see Eq. (9)). Shaded areas encompass the curves obtained with Eq. (9) by using the two values of κ (see Fig. 2 for colour-coding). The telescope beam is shown in the leftmost column for models A, B, and C (dotted black line, 300″), B68 (short-dashed black line, 330″), and FeSt 1-457 (long-dashed black line, 284″). Hatched areas display SKA sensitivities for one hour of integration at different frequencies. The two panels on the right side show the flux density as a function of frequency. Empty (solid) circles refer to an S/N smaller (larger) than 3, respectively. The spectral index α is shown on the right of each curve.

Open with DEXTER

thumbnail Fig. 4.

Flux density at 60, 114, and 218 MHz (lower-left labels) as a function of magnetic field strength B0 for model B (see Sect. 5.1). Green shaded areas encompass the curves obtained with Eq. (9) by using κ = 0.5 and 0.7. Grey areas correspond to an S/N <  3 and dashed lines are power-law fits of with δ listed in the upper-right corner.

Open with DEXTER


1

We thank Alexei Ivlev for pointing out this mistake.


© ESO 2020

All Figures

thumbnail Fig. 3.

Radial flux density profiles for the starless core models described in Sect. 5.1 (upper row) and for B68 and FeSt 1-457 (lower row, see Sect. 5.2). The observing frequency is shown in black at the top of each column, while numbers in the upper-right corner of each subplot represent the radius-averaged S/N for the two values of κ (0.5 and 0.7 for models A, B, C, and B68, and 0.68 and 0.88 for FeSt 1-457, see Eq. (9)). Shaded areas encompass the curves obtained with Eq. (9) by using the two values of κ (see Fig. 2 for colour-coding). The telescope beam is shown in the leftmost column for models A, B, and C (dotted black line, 300″), B68 (short-dashed black line, 330″), and FeSt 1-457 (long-dashed black line, 284″). Hatched areas display SKA sensitivities for one hour of integration at different frequencies. The two panels on the right side show the flux density as a function of frequency. Empty (solid) circles refer to an S/N smaller (larger) than 3, respectively. The spectral index α is shown on the right of each curve.

Open with DEXTER
In the text
thumbnail Fig. 4.

Flux density at 60, 114, and 218 MHz (lower-left labels) as a function of magnetic field strength B0 for model B (see Sect. 5.1). Green shaded areas encompass the curves obtained with Eq. (9) by using κ = 0.5 and 0.7. Grey areas correspond to an S/N <  3 and dashed lines are power-law fits of with δ listed in the upper-right corner.

Open with DEXTER
In the text

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