Search Publications
The UNCOVER Survey: A First-look HST + JWST Catalog of 60,000 Galaxies near A2744 and beyond
Papovich, Casey; Maseda, Michael V.; Franx, Marijn +43 more
In 2022 November, the James Webb Space Telescope (JWST) returned deep near-infrared images of A2744-a powerful lensing cluster capable of magnifying distant, incipient galaxies beyond it. Together with existing Hubble Space Telescope (HST) imaging, this publicly available data set opens a fundamentally new discovery space to understand the remaini…
JWST NIRSpec Spectroscopy of the Triply Lensed z = 10.17 Galaxy MACS0647–JD
Hutchison, Taylor A.; Larson, Rebecca L.; Wilkins, Stephen M. +38 more
We present JWST/NIRSpec prism spectroscopy of MACS0647‑JD, a triply lensed z ∼ 11 candidate discovered in Hubble Space Telescope imaging and spatially resolved by JWST imaging into two components, A and B. Spectroscopy of component A yields a spectroscopic redshift z = 10.17 based on seven detected emission lines: C III] λ λ1907, 1909, [O II] λ372…
JWST PRIMER: a new multifield determination of the evolving galaxy UV luminosity function at redshifts z ≃ 9 - 15
Bowler, R. A. A.; Cullen, F.; McLure, R. J. +18 more
We present a new determination of the evolving galaxy ultraviolet (UV) luminosity function (LF) over the redshift range
A NICER View of the Nearest and Brightest Millisecond Pulsar: PSR J0437–4715
Remillard, Ronald A.; Bogdanov, Slavko; Salmi, Tuomo +17 more
We report Bayesian inference of the mass, radius, and hot X-ray emitting region properties—using data from the Neutron Star Interior Composition ExploreR (NICER)—for the brightest rotation-powered millisecond X-ray pulsar, PSR J0437‑4715. Our modeling is conditional on informative tight priors on mass, distance, and binary inclination obtained fro…
Metal-poor star formation at z > 6 with JWST: new insight into hard radiation fields and nitrogen enrichment on 20 pc scales
Charlot, Stéphane; Chevallard, Jacopo; Maseda, Michael V. +11 more
Nearly a decade ago, we began to see indications that reionization-era galaxies power hard radiation fields rarely seen at lower redshift. Most striking were detections of nebular C IV emission in what appeared to be typical low-mass galaxies, requiring an ample supply of 48 eV photons to triply ionize carbon. We have obtained deep JWST/NIRSpec R …
Bound star clusters observed in a lensed galaxy 460 Myr after the Big Bang
Mahler, Guillaume; Fujimoto, Seiji; Inoue, Akio K. +25 more
The Cosmic Gems arc is among the brightest and highly magnified galaxies observed at redshift z ≈ 10.2 (ref. 1). However, it is an intrinsically ultraviolet faint galaxy, in the range of those now thought to drive the reionization of the Universe2–4. Hitherto the smallest features resolved in a galaxy at a comparable redshift…
COSMOS-Web: Intrinsically Luminous z ≳ 10 Galaxy Candidates Test Early Stellar Mass Assembly
Finkelstein, Steven L.; Casey, Caitlin M.; Kartaltepe, Jeyhan S. +39 more
We report the discovery of 15 exceptionally luminous 10 ≲ z ≲ 14 candidate galaxies discovered in the first 0.28 deg2 of JWST/NIRCam imaging from the COSMOS-Web survey. These sources span rest-frame UV magnitudes of ‑20.5 > M UV > ‑22, and thus constitute the most intrinsically luminous z ≳ 10 candidates identified by J…
JWST Measurements of Neutral Hydrogen Fractions and Ionized Bubble Sizes at z = 7–12 Obtained with Lyα Damping Wing Absorptions in 27 Bright Continuum Galaxies
Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +5 more
We present volume-averaged neutral hydrogen fractions x H I and ionized bubble radii R b measured with Lyα damping wing absorption of galaxies at the epoch of reionization. We combine JWST/NIRSpec spectra taken by the CEERS, GO-1433, DDT-2750, and JADES programs and obtain a sample containing 27 bright UV-continuum (M UV…
Strong damped Lyman-α absorption in young star-forming galaxies at redshifts 9 to 11
Finkelstein, Steven L.; Arrabal Haro, Pablo; Heintz, Kasper E. +18 more
Primordial neutral atomic gas, mostly composed of hydrogen, is the raw material for star formation in galaxies. However, there are few direct constraints on the amount of neutral atomic hydrogen (H I) in galaxies at early cosmic times. We analyzed James Webb Space Telescope (JWST) near-infrared spectroscopy of distant galaxies, at redshifts ≳8. Fr…
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic Star Formation Rate Density 300 Myr after the Big Bang
Pérez-González, Pablo G.; Chevallard, Jacopo; Maseda, Michael V. +33 more
We characterize the earliest galaxy population in the JADES Origins Field, the deepest imaging field observed with JWST. We make use of ancillary Hubble Space Telescope optical images (five filters spanning 0.4–0.9 µm) and novel JWST images with 14 filters spanning 0.8‑5 µm, including seven medium-band filters, and reaching total expos…