# DUALZ -- Deep UNCOVER-ALMA Legacy High-$Z$ Survey

**Authors:** Seiji Fujimoto, Rachel Bezanson, Ivo Labbe, Gabriel Brammer, Sedona H. Price, Bingjie Wang, John R. Weaver, Yoshinobu Fudamoto, Pascal A. Oesch, Christina C. Williams, Pratika Dayal, Robert Feldmann, Jenny E. Greene, Joel Leja, Katherine E. Whitaker, Adi Zitrin, Sam E. Cutler, Lukas J. Furtak, Richard Pan, Iryna Chemerynska  
**arXiv:** [2309.07834](https://arxiv.org/abs/2309.07834)  
**Date:** 2023-09-14  
**Summary page:** https://www.summarizepaper.com/en/paper/2309.07834v1/

## Key points

- ALMA Cycle 9 program of DUALZ aims to establish a joint ALMA and JWST public legacy field targeting the massive galaxy cluster Abell 2744
- DUALZ program features a contiguous $4'\times6'$ ALMA 30-GHz-wide mosaic in Band 6
- Identified 69 dust continuum sources with S/N greater than or equal to 5.0, with median redshift of $z=2.30$ and intrinsic flux at 1.2 mm wavelength ($S_{\rm 1.2mm}^{\rm int}$) of $0.24$ mJy
- Spectroscopically confirmed 27 sources using NIRSpec observations, while photometric redshift estimates available for remaining sources based on \hst, NIRCam, and ALMA data
- Discovered a \cii158 $\mu$m line emitter at redshift $z=6.3254\pm0.0004$, confirmed through NIRSpec spectroscopy
- Observed undisturbed morphologies in counterparts of the observed continuum sources with NIRCam, indicating less catastrophic triggers for faint millimeter emission compared to mergers
- Discovered eight \hst-dark galaxies and two JWST-dark galaxy candidates among the ALMA continuum sources
- Detected marginal dust emission from an X-ray-detected galaxy at a spectroscopic redshift of $z_{\rm spec}=10.07$, suggesting active coevolution between its central black hole and host galaxy up to high redshifts ($z\sim10$)
- Assessed infrared luminosity function up to this redshift range and found it consistent with predictions from galaxy formation models

## Summary

We present the survey design and initial results of the ALMA Cycle 9 program of DUALZ, which aims to establish a joint ALMA and JWST public legacy field targeting the massive galaxy cluster Abell 2744. The DUALZ program features a contiguous $4'\times6'$ ALMA 30-GHz-wide mosaic in Band 6, covering areas with surface brightness $\mu>2$ down to a sensitivity of $\sigma=32.7$ $\mu$Jy. Through a blind search, we have identified 69 dust continuum sources at signal-to-noise ratio (S/N) greater than or equal to 5.0. These sources have a median redshift of $z=2.30$ and an intrinsic flux at 1.2 mm wavelength ($S_{\rm 1.2mm}^{\rm int}$) of $0.24$ mJy. Of these sources, 27 have been spectroscopically confirmed using the latest NIRSpec observations, while photometric redshift estimates are available for the remaining sources based on comprehensive data from \hst, NIRCam, and ALMA. In addition to the continuum sources, we have also identified a \cii158 $\mu$m line emitter at redshift $z=6.3254\pm0.0004$, which has been confirmed through NIRSpec spectroscopy. The counterparts of the 1.2-mm continuum sources observed with NIRCam exhibit undisturbed morphologies, indicating that triggers for faint millimeter emission are less catastrophic than mergers. We have also discovered eight \hst-dark galaxies and two JWST-dark galaxy candidates among the ALMA continuum sources as well as marginal dust emission from an X-ray-detected galaxy at a spectroscopic redshift of $z_{\rm spec}=10.07$, suggesting active coevolution between its central black hole and host galaxy up to high redshifts ($z\sim10$). We have assessed the infrared luminosity function up to this redshift range and found it consistent with predictions from galaxy formation models.