Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies

Understand

We present new results on [CII]158$\mu$ m emission from four galaxies in the reionization epoch.

• These galaxies were previously confirmed to be at redshifts between 6.6 and 7.15 from the presence of the Ly$\alpha$ emission line in their spectra.
• The Ly$\alpha$ emission line is redshifted by 100-200 km/s compared to the systemic redshift given by the [CII] line.
• These velocity offsets are smaller than what is observed in z~3 Lyman break galaxies with similar UV luminosities and emission line properties.