Search Publications
The Small Sizes and High Implied Densities of "Little Red Dots" with Balmer Breaks Could Explain Their Broad Emission Lines without an Active Galactic Nucleus
Maseda, Michael V.; Franx, Marijn; Labbé, Ivo +10 more
Early JWST studies found an apparent population of massive, compact galaxies at redshifts z ≳ 7. Recently three of these galaxies were shown to have prominent Balmer breaks, demonstrating that their light at λrest ∼ 3500 Å is dominated by a stellar population that is relatively old (∼200 Myr). All three also have broad Hβ emission with …
A More Precise Measurement of the Radius of PSR J0740+6620 Using Updated NICER Data
Bogdanov, Slavko; Wolff, Michael T.; Arzoumanian, Zaven +9 more
PSR J0740+6620 is the neutron star with the highest precisely determined mass, inferred from radio observations to be 2.08 ± 0.07 M ⊙. Measurements of its radius therefore hold promise to constrain the properties of the cold, catalyzed, high-density matter in neutron star cores. Previously, Miller et al. and Riley et al. reported measur…
Evolution of the Size–Mass Relation of Star-forming Galaxies Since z = 5.5 Revealed by CEERS
Papovich, Casey; Finkelstein, Steven L.; Arrabal Haro, Pablo +19 more
We combine deep imaging data from the CEERS early release JWST survey and Hubble Space Telescope imaging from CANDELS to examine the size–mass relation of star-forming galaxies and the morphology–quenching relation at stellar masses M ⋆ ≥ 109.5 M ⊙ over the redshift range 0.5 < z < 5.5. In this study with a s…
JWST Validates HST Distance Measurements: Selection of Supernova Subsample Explains Differences in JWST Estimates of Local H 0
Casertano, Stefano; Filippenko, Alexei V.; Li, Siyang +16 more
We cross-check the Hubble Space Telescope (HST) Cepheid/Type Ia supernova (SN Ia) distance ladder, which yields the most precise local H 0, against early James Webb Space Telescope (JWST) subsamples (∼1/4 of the HST sample) from SH0ES and CCHP, calibrated only with NGC 4258. We find HST Cepheid distances agree well (∼1σ) with all combin…
Quantifying the Effects of Known Unknowns on Inferred High-redshift Galaxy Properties: Burstiness, IMF, and Nebular Physics
Labbé, Ivo; Bezanson, Rachel; Price, Sedona H. +15 more
The era of the James Webb Space Telescope ushers stellar population models into uncharted territories, particularly at the high-redshift frontier. In a companion paper, we apply the Prospector Bayesian framework to jointly infer galaxy redshifts and stellar population properties from broadband photometry as part of the UNCOVER survey. Here we pres…
A Steep Decline in the Galaxy Space Density beyond Redshift 9 in the CANUCS UV Luminosity Function
Willott, Chris J.; Martis, Nicholas S.; Rihtaršič, Gregor +15 more
We present a new sample of 158 galaxies at redshift z > 7.5 selected from deep James Webb Space Telescope (JWST) NIRCam imaging of five widely separated sight lines in the CANUCS survey. Two-thirds of the pointings and 80% of the galaxies are covered by 12–14 NIRCam filters, including seven to nine medium bands, providing accurate photometric r…
Rapid Chemical Enrichment by Intermittent Star Formation in GN-z11
Ferrara, Andrea; Kobayashi, Chiaki
We interpret the peculiar supersolar nitrogen abundance recently reported by the James Webb Space Telescope observations for GN-z11 (z = 10.6) using our state-of-the-art chemical evolution models. The observed CNO ratios can be successfully reproduced—independently of the adopted initial mass function, nucleosynthesis yields, and presence of super…
A Candidate Supermassive Black Hole in a Gravitationally Lensed Galaxy at Z ≈ 10
Azadi, Mojegan; Jones, Christine; Volonteri, Marta +8 more
While supermassive black holes (SMBHs) are widely observed in the nearby and distant Universe, their origin remains debated with two viable formation scenarios with light and heavy seeds. In the light seeding model, the seed of the first SMBHs form from the collapse of massive stars with masses of 10–100 M ⊙, while the heavy seeding mod…
Bright z ∼ 9 Galaxies in Parallel: The Bright End of the Rest-frame UV Luminosity Function from HST Parallel Programs
Papovich, Casey; Finkelstein, Steven L.; Bagley, Micaela B. +7 more
The abundance of bright galaxies at z > 8 can provide key constraints on models of galaxy formation and evolution, as the predicted abundance varies greatly when different physical prescriptions for gas cooling and star formation are implemented. We present the results of a search for bright z ∼ 9–10 galaxies selected from pure parallel Hubble …
Efficient NIRCam Selection of Quiescent Galaxies at 3 < z < 6 in CEERS
Papovich, Casey; Finkelstein, Steven L.; Pérez-González, Pablo G. +31 more
Substantial populations of massive quiescent galaxies at z ≥ 3 challenge our understanding of rapid galaxy growth and quenching over short timescales. In order to piece together this evolutionary puzzle, more statistical samples of these objects are required. Established techniques for identifying massive quiescent galaxies are increasingly ineffi…