We analyze the >4σ sources in the most sensitive 100 arcmin2 area (rms?μm survey of the GOODS-S and present the 75 band-7 ALMA sources (>4.5σ) obtained from high-resolution interferometric follow-up observations. The raw SCUBA-2?>4σ limit is fainter than 2.25 mJy throughout this region, and deboosting corrections would lower this further. Of the 53 SCUBA-2 sources in this sample, only five have no ALMA detections, while 13% (68% confidence range 7%–19%) have multiple ALMA counterparts. Color-based high-redshift dusty galaxy selection techniques find at most 55% of the total ALMA sample. In addition to using literature spectroscopic and opticalear-infrared photometric redshifts, we estimate far infrared photometric redshifts based on an Arp?220 template. We identify seven z??4 candidates. We see the expected decline with redshift of the 4.5 and 24 μm to 850 μm flux ratios, confirming these as good diagnostics of z??4 candidates. We visually classify 52 ALMA sources, finding 44% (68% confidence range 35%–53%) to be apparent mergers. We calculate rest-frame 2–8 keV and 8–28 keV luminosities using the 7 Ms Chandra?X-ray image. Nearly all of the ALMA sources detected at 0.5–2 keV are consistent with a known X-ray luminosity to 850 μm flux relation for star-forming galaxies, while most of those detected at 2–7 keV are moderate-luminosity AGNs that lie just above the 2–7 keV detection threshold. The latter largely have substantial obscurations of cm?2, but two of the high-redshift candidates may even be Compton thick.
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