EPOCHS-DR2 I: Expanded data release and properties of $6.5<z<16.5$ photometrically selected galaxies across NIRCam deep fields covering $\sim700\,\rm arcmin^2$ with the galfind software

Duncan Austin, Christopher J. Conselice, Thomas Harvey, Nathan J. Adams, Louis Quilley, Jordan C. J. D'Silva, Vadim Rusakov, Qiong Li, Lewi Westcott, Caio Goolsby, James Arcidiacono, Kai Madgwick, William J. Roper, Brenda Frye, Norman A. Grogin, Rafael Ortiz, Rogier Windhorst

First listed 2026-09-22 | Last updated 2026-09-21

Abstract

We present the \epochstwo\ sample of $2452$ star forming galaxies at $6.5<z_{\rm phot}<16.5$ produced using the \galfind\ photometric pipeline across $\sim650-740~\mathrm{arcmin}^2$ in six of the most widely used deep, blank field \jwst/NIRCam imaging surveys. $293$ galaxies are spectroscopically confirmed and a spectroscopic--photometric redshift comparison yields a normalized median absolute deviation, $σ_{\rm NMAD}=0.017$, an $η=4.3\%$ outlier rate, and a mean offset $\langleΔz\rangle=-0.022$. We find $34$ little red dots (LRDs) with ``V--shaped'' SEDs, as well as $69$ L--type, $36$ T--type, and $2$ compact Y--type brown dwarf candidates, which we remove from our sample. The fiducial sample yields a flattening $β_{\rm UV}-M_{\rm UV}$ relation with only moderately blue median $β_{\rm UV}(M_{\rm UV}=-19)=-2.32^{+0.08}_{-0.07}$ at $z\simeq12.5$, implying dust-polluted stellar populations at the highest redshifts. A ``gold'' sample of $62$ sources are identified at $z_{\rm phot}>10.5$, $\sim85\%$ of which are without NIRSpec follow-up, including $15$ candidates at $z_{\rm phot}>13.5$ across a diverse range of proper sizes $30\,\rm pc\lesssim r_{\rm c}\lesssim1.5\,\rm kpc$ and UV slopes $-4.0\lesssimβ_{\rm UV}\lesssim-1.5$. Two very promising candidates stand out, GS-W-4608 and GN-Med-1881, with $β_{\rm UV}\lesssim-3$, $\gtrsim1.6\,\rm mag$ \lya\ break colors, and F335M and F410M detections which improve their high-redshift solution robustness. Complementary to our high-redshift sample, this public data release provides the community with optical/NIR catalogs, empirical PSFs, and \eazypy, \bagpipes, and \bdfinder\ SED fitting results, enhancing the legacy value of photometric JWST data in the upcoming era of wide-field imaging datasets with Euclid and Roman.

Short digest

EPOCHS-DR2 releases a homogeneous galfind-based catalog of 2,452 photometrically selected star-forming galaxies at 6.5<zphot<16.5 across six JWST/NIRCam deep fields spanning roughly 650–740 arcmin², together with imaging products, empirical PSFs, and multiple SED-fitting outputs. Its photo-z selection is benchmarked against 293 spectroscopic confirmations, achieving σNMAD=0.017 with a 4.3% outlier rate, while explicitly identifying and removing 34 V-shaped-SED little red dots and 107 brown-dwarf candidates. The catalog also isolates 62 zphot>10.5 “gold” candidates, including 15 at zphot>13.5; GS-W-4608 and GN-Med-1881 are particularly robust owing to very blue UV slopes, strong Lyman-break colors, and supporting F335M/F410M detections. The measured flattening of the βUV–MUV relation, with βUV(MUV=-19)≈-2.32 at z≈12.5, points to moderately dust-polluted stellar populations even at the highest redshifts.

Key figures to inspect

• Figure 3. This is the clearest overview of the full photometric selection in redshift–UV-luminosity space, distinguishing the z>10.5 gold sample from the larger catalog and placing it alongside spectroscopically confirmed sources.
• Figure 4. This diagnostic directly shows how the 34 LRDs and 107 brown-dwarf candidates separate from the fiducial galaxy sample in photometric-redshift, luminosity, compactness, and stellar-mass space, making the contaminant removal central to the release tangible.
• Figure 5. The spectroscopic-versus-photometric redshift comparison substantiates the catalog’s claimed photo-z performance and explains the adoption of the sfhz_blue_agn template set as the fiducial solution.
• Figure 11. This Lyman/Balmer-break versus UV/optical-slope diagnostic tests the most extreme zphot=13.5–16.5 gold candidates against likely z≈4 LRD and quiescent-galaxy contaminants, providing the key physical caveat for the highest-redshift sample.