# The Cosmos in its Infancy: JADES Galaxy Candidates at z > 8 in GOODS-S and GOODS-N

**Authors:** Kevin N. Hainline, Benjamin D. Johnson, Brant Robertson, Sandro Tacchella, Jakob M. Helton, Fengwu Sun, Daniel J. Eisenstein, Charlotte Simmonds, Michael W. Topping, Lily Whitler, Christopher N. A. Willmer, Marcia Rieke, Katherine A. Suess, Raphael E. Hviding, Alex J. Cameron, Stacey Alberts, William M. Baker, Rachana Bhatawdekar, Kristan Boyett, Andrew J. Bunker  
**arXiv:** [2306.02468](https://arxiv.org/abs/2306.02468)  
**Date:** 2023-06-04  
**Summary page:** https://www.summarizepaper.com/en/paper/2306.02468v1/

## Key points

- JADES produced a catalog of 717 candidate galaxies at redshifts greater than 8 from NIRCam imaging in the GOODS-S and GOODS-N fields.
- The catalog is one of the largest samples of high-redshift galaxy candidates to date and provides an opportunity to study the early buildup of galaxies within the first few hundred million years of the Universe's history.
- Data from multiple sources, including JEMS and FRESCO JWST surveys, as well as extremely deep observations from HST/ACS were combined for the JADES survey.
- High-redshift galaxy candidates were selected based on their estimated photometric redshifts calculated using a template fitting approach, followed by visual inspection from seven independent reviewers.
- Over 93% of the sources in this catalog are newly identified from deep JADES imaging, including 31 new galaxy candidates at $z_{phot} > 12$.
- Using spectroscopic redshift measurements from NIRSpec and FRESCO for a subset of 42 sources in the sample, excellent agreement was found between photometric and spectroscopic redshift estimates with no catastrophic outliers and an average difference of $\langle \Delta z = z_{phot} - z_{spec} \rangle= 0.26$.
- The catalog will be a valuable resource for future studies of the early Universe, particularly with the upcoming launch of JWST which will provide even deeper imaging and spectroscopy in these fields.

## Summary

The JWST Advanced Deep Extragalactic Survey (JADES) has produced a catalog of 717 candidate galaxies at redshifts greater than 8, selected from 125 square arcminutes of NIRCam imaging in the GOODS-S and GOODS-N fields. This catalog is one of the largest samples of high-redshift galaxy candidates to date and provides an opportunity to study the early buildup of galaxies within the first few hundred million years of the Universe's history. The JADES survey combines data from multiple sources, including JEMS and FRESCO JWST surveys, as well as extremely deep observations from HST/ACS. The final filter set includes fifteen JWST/NIRCam filters and five HST/ACS filters. The high-redshift galaxy candidates were selected based on their estimated photometric redshifts calculated using a template fitting approach, followed by visual inspection from seven independent reviewers. The catalog includes interesting resolved or extended sources, sources with very red long-wavelength slopes, and the highest redshift candidates that extend up to $z_{phot} = 18$. To investigate potential contamination by stellar objects, SED fitting was used to determine whether these faint high-redshift galaxy candidates are low-mass stars. The analysis did not find strong evidence for such contamination. Over 93% of the sources in this catalog are newly identified from deep JADES imaging, including 31 new galaxy candidates at $z_{phot} > 12$. Using spectroscopic redshift measurements from NIRSpec and FRESCO for a subset of 42 sources in the sample, excellent agreement was found between photometric and spectroscopic redshift estimates with no catastrophic outliers and an average difference of $\langle \Delta z = z_{phot} - z_{spec} \rangle= 0.26$. This robust sample provides an opportunity to probe the early buildup of galaxies within the first few hundred million years after the Big Bang. The catalog will be a valuable resource for future studies of the early Universe, particularly with the upcoming launch of JWST which will provide even deeper imaging and spectroscopy in these fields.