Science Highlight




Science Highlight: Normal, Dust-Obscured Galaxies in the Epoch of Reionization


As part of the ongoing ALMA large program REBELS (Reionization-Era Bright Emission Line Survey), 40 UV-luminous primary targets were observed at z > 6.5. Among these targets are REBELS-12 and REBELS-29. In their recent paper, Fudamoto and colleagues report two additional emission line neighbours found after inspecting the ALMA data cube of these two sources.

The images on the left show [CII] 158 ¬Ķm line and dust emission detections for (a) the REBELS-29 field at z‚ąľ6.68 and (b) the REBELS-12 field at z‚ąľ7.35.¬†Background images are HST F140W and VIDEO J-band, respectively. White horizontal bars correspond¬†to 10 proper kpc. Solid red and light blue contours show 2ŌÉ to 5ŌÉ levels (and ‚ąí5ŌÉ to ‚ąí2ŌÉ for dashed contours) for the continuum and [CII]¬†moment-0 maps, respectively. The continuum subtracted [CII] spectra are shown at the native velocity resolution of 20 km/s. The two¬†sources REBELS-29-2 and REBELS-12-2 were found serendipitously as companions to the central, UV-luminous targets, with emission¬†lines at almost exactly the same frequencies as the central targets, accompanied with dust continuum emission at the same location. Their¬†spatial and spectral proximity, and absence in optical/NIR images confirms these companions as unexpected, dusty star forming sources in¬†the epoch of reionization.¬†

 ALMA Science