Related papers: Strong Balmer break objects at z ~ 7-10 uncovered …
Standard models of structure formation allow us to predict the cosmic timescales relevant for the onset of star formation and the assembly history of galaxies at high redshifts ($z > 10$). The strength of the Balmer break represents a…
The presence of evolved stars in high-redshift galaxies can place valuable indirect constraints on the onset of star formation in the Universe. Thus we use PEARLS GTO and public NIRCam photometric data to search for Balmer-break candidate…
Early JWST spectroscopic campaigns have confirmed the presence of strong [O III] line-emitting galaxies in the redshift interval $7<z<9$. Although deduced earlier from Spitzer photometry as indicative of young stellar populations, some…
We present a reduction and analysis of the \textit{James Webb Space Telescope} (JWST) SMACS~0723 field using new post-launch calibrations to conduct a search for ultra-high-redshift galaxies ($z > 9$) present within the Epoch of…
We use data taken as part of HST/WFC3 observations of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) to identify massive and evolved galaxies at 3<z<4.5. This is performed using the strength of the Balmer break…
Theoretical models and observational evidence suggest that high-redshift galaxies grow under the bursty mode of star formation, with large temporal star formation rate (SFR) fluctuations around some mean value. From an observational…
Early JWST observations that targeted so-called double-break sources (attributed to Lyman and Balmer breaks at $z>7$), reported a previously unknown population of very massive, evolved high-redshift galaxies. This surprising discovery led…
We search for galaxies with a strong Balmer break (Balmer Break Galaxies; BBGs) at $z \sim 6$ over a 0.41 deg$^2$ effective area in the COSMOS field. Based on rich imaging data, including data obtained with the Atacama Large…
From James Webb Space Telescope (JWST) surveys, 31 galaxies with average redshift 7.3 are selected containing large Balmer break, Lyman-$\alpha$ break (V-shaped SED versus $\lambda$). Apart from Hubble Space Telescope (HST) and JWST-NIRCam…
We present a first-look analysis of the JWST ERO data in the SMACS J0723.3-7327 cluster field. We begin by reporting 10 new spectroscopic redshifts from $\lambda_\mathrm{obs}=1.8-5.2\mu$m NIRSpec medium-resolution ($R=\lambda/\Delta\lambda…
We report results from a search for massive and evolved galaxies at z>5 in the GOODS southern field. Combining HST ACS, VLT ISAAC and Spitzer IRAC photometric data, we develop a color selection technique to identify candidates for being…
Surveys with James Webb Space Telescope (JWST) have discovered candidate galaxies in the first 400 Myr of cosmic time. Preliminary indications have suggested these candidate galaxies may be more massive and abundant than previously thought.…
Photometric observations of the spectroscopically confirmed $z\approx 9.1$ galaxy MACS1149-JD1 have indicated the presence of a prominent Balmer break in its spectral energy distribution, which may be interpreted as due to very large…
The exceptional spectra of the most luminous $z>10$ sources observed so far have challenged our understanding of early galaxy evolution, requiring a new observational benchmark for meaningful interpretation. As such, we construct…
The identification of red, apparently massive galaxies at $z>7$ in early JWST photometry suggests a strongly accelerated timeline compared to standard models of galaxy growth. A major uncertainty in the interpretation is whether the red…
We present a sample of 33 Balmer Break Galaxies (BBGs) selected as HST/F160W dropouts in the deepest CANDELS/GOODS fields ($H\gtrsim27.3$~mag) but relatively bright in {\it Spitzer}/IRAC ($[3.6],[4.5]<24.5$~mag), implying red colors (median…
Recent studies have reported tension between the presence of luminous, high-redshift galaxies and the halo mass functions predicted by standard cosmology. Here, an improved test is proposed using the presence of high-redshift Balmer breaks…
Aims. We present a spectroscopic study of the properties of 64 Balmer break galaxies that show signs of star formation. The studied sample of star-forming galaxies spans a redshift range from 0.094 to 1.475 with stellar masses in the range…
We have exploited the large area coverage of the combined UKIDSS Ultra Deep Survey (UDS) and Subaru/XMM-Newton Deep Survey (SXDS) to search for bright Lyman-break galaxies (LBGs) at z >= 5. Using the available optical+near-infrared…
The presence of spectroscopically confirmed Balmer breaks in galaxy spectral energy distributions (SEDs) at $z>9$ provides one of the best probes of the assembly history of the first generations of stars in our Universe. Recent observations…