Detection of new galaxy candidates at z > 11 in the JADES field using JWST NIRCam

We report the detection of six new galaxy candidates with photometric redshifts $z$ $>$ 11 within the JWST Advanced Deep Extragalactic Survey (JADES) GOODS-S and GOODS-N fields. These new candidates are detected through meticulous analysis of NIRCam photometry in eight filters spanning a wavelength range of 0.8-5.0 $μ$m. Photometric redshifts of these galaxy candidates are independently measured utilizing spectral energy distribution (SED) fitting techniques using \texttt{EAZY} and \texttt{BAGPIPES} codes, followed by visual scrutiny. One of these galaxy candidates is located in GOODS-S field, while the remaining five galaxies are located in GOODS-N field. Our analysis reveals that the stellar masses of these galaxies typically range from log $M_{\ast}$/$M_{\odot}$ = 7.75–8.75. Furthermore, these galaxies are typically young with their mass-weighted ages spanning from 80 to 240 Myr. Their specific star formation rates (sSFR), quantified as $\log (\text{sSFR}/\text{Gyr}$), are measured to vary between $\sim 0.95$ to 1.46. These new galaxy candidates offer a robust sample for probing the physical properties of galaxies within the first few hundred Myr of the history of the Universe. We also analyze the relationship between star formation rate (SFR) and stellar mass ($M_\ast$) within our sample.Continued investigation through spectroscopic analysis using JWST/NIRSpec is needed to spectroscopically confirm these high-redshift galaxy candidates and investigate further into their physical properties. We plan to follow up on these candidates with future NIRSpec observations.

💡 Research Summary

This paper presents the independent discovery and characterization of six new galaxy candidates at redshifts greater than 11 (z > 11) using JWST NIRCam imaging from the JADES (JWST Advanced Deep Extragalactic Survey) program in the GOODS‑South and GOODS‑North fields. The authors processed publicly released JADES data covering eight NIRCam filters (F090W, F115W, F150W, F200W, F277W, F356W, F410M, and F444W) spanning 0.8–5.0 µm, with 5σ depths between 3.4 and 5.9 nJy. A detection image was created by weighted combination of the F200W and F277W bands; source extraction employed Photutils segmentation with a signal‑to‑noise ratio (SNR) > 3 across at least five contiguous pixels. Fluxes were measured using flexible Kron apertures (scale factor K = 1.5) and corrected for aperture losses by comparing larger and smaller apertures, ensuring accurate colour measurements for faint high‑z objects.

Photometric redshifts were derived with the Python implementation of EAZY (EAZY‑py). The template set combined 12 FSPS‑based spectra (including star‑forming, quiescent, and dusty types) with six additional high‑z‑optimized templates from Larson et al. (2023). Redshift space was sampled from 0.1 to 20 in steps of 0.01, assuming a flat luminosity prior to avoid bias against bright high‑z sources. The χ²(z) distribution was converted to a probability density P(z) = exp