ALMA twenty-six arcmin$^2$ survey of GOODS-S at one-millimeter (ASAGAO): Near-infrared-dark faint ALMA sources

Understand

We report detections of two 1.2 mm continuum sources ($S_\mathrm{1.2mm}$ ~ 0.6 mJy) without any counterparts in the deep $H$- and/or $K$-band image (i.e., $K$-band magnitude $\gtrsim$ 26 mag).

• These near-infrared-dark faint millimeter sources are uncovered by ASAGAO, a deep and wide-field ($\simeq$ 26 arcmin$^2$) Atacama Large Millimeter/submillimeter Array (ALMA) 1.2 mm survey.
• One has a red IRAC (3.6 and 4.5 $\mu$m) counterpart, and the other has been independently detected at 850 and 870 $\mu$m using SCUBA2 and ALMA Band 7, respectively.
• Their optical to radio spectral energy distributions indicate that they can lie at $z \gtrsim$ 3-5 and can be in the early phase of massive galaxy formation.