Search Publications
Small-amplitude Red Giants Elucidate the Nature of the Tip of the Red Giant Branch as a Standard Candle
Anderson, Richard I.; Eyer, Laurent; Koblischke, Nolan W.
The tip of the red giant branch (TRGB) is an important standard candle for determining luminosity distances. Although several 105 small-amplitude red giant stars (SARGs) have been discovered, variability was previously considered irrelevant for the TRGB as a standard candle. Here, we show that all stars near the TRGB are SARGs that foll…
The Sonora Substellar Atmosphere Models. IV. Elf Owl: Atmospheric Mixing and Chemical Disequilibrium with Varying Metallicity and C/O Ratios
Fortney, Jonathan J.; Batalha, Natasha E.; Marley, Mark S. +7 more
Disequilibrium chemistry due to vertical mixing in the atmospheres of many brown dwarfs and giant exoplanets is well established. Atmosphere models for these objects typically parameterize mixing with the highly uncertain K zz diffusion parameter. The role of mixing in altering the abundances of C-N-O-bearing molecules has mostly been…
Charting the Galactic Acceleration Field. II. A Global Mass Model of the Milky Way from the STREAMFINDER Atlas of Stellar Streams Detected in Gaia DR3
Bianchini, Paolo; Malhan, Khyati; Martin, Nicolas F. +17 more
We present an atlas and follow-up spectroscopic observations of 87 thin stream-like structures detected with the STREAMFINDER algorithm in Gaia DR3, of which 28 are new discoveries. Here, we focus on using these streams to refine mass models of the Galaxy. Fits with a double-power-law halo with the outer power-law slope set to ‑β h = …
Quaia, the Gaia-unWISE Quasar Catalog: An All-sky Spectroscopic Quasar Sample
Hogg, David W.; Rix, Hans-Walter; Eilers, Anna-Christina +4 more
We present a new, all-sky quasar catalog, Quaia, that samples the largest comoving volume of any existing spectroscopic quasar sample. The catalog draws on the 6,649,162 quasar candidates identified by the Gaia mission that have redshift estimates from the space observatory's low-resolution blue photometer/red photometer spectra. This initial samp…
JADES + JEMS: A Detailed Look at the Buildup of Central Stellar Cores and Suppression of Star Formation in Galaxies at Redshifts 3 < z < 4.5
Chevallard, Jacopo; Maseda, Michael V.; Carniani, Stefano +30 more
We present a spatially resolved study of stellar populations in six galaxies with stellar masses M * ∼ 1010 M ☉ at z ∼ 3.7 using 14-filter James Webb Space Telescope (JWST)/NIRCam imaging from the JADES and JEMS surveys. The six galaxies are visually selected to have clumpy substructures with distinct colors over r…
Size–Stellar Mass Relation and Morphology of Quiescent Galaxies at z ≥ 3 in Public JWST Fields
Heintz, Kasper E.; Brammer, Gabriel; Ilbert, Olivier +19 more
We present the results of a systematic study of the rest-frame optical morphology of quiescent galaxies at z ≥ 3 using the Near-Infrared Camera (NIRCam) on board the James Webb Space Telescope (JWST). Based on a sample selected by UVJ color or NUVUVJ color, we focus on 26 quiescent galaxies with $9.8\lt \mathrm{log}({M}_{\star }/{M}_{\odot })\lt 1…
Unveiling the Distant Universe: Characterizing z ≥ 9 Galaxies in the First Epoch of COSMOS-Web
Finkelstein, Steven L.; Bagley, Micaela B.; Casey, Caitlin M. +48 more
We report the identification of 15 galaxy candidates at z ≥ 9 using the initial COSMOS-Web JWST observations over 77 arcmin2 through four Near Infrared Camera filters (F115W, F150W, F277W, and F444W) with an overlap with the Mid-Infrared Imager (F770W) of 8.7 arcmin2. We fit the sample using several publicly available spectra…
EMPRESS. XIII. Chemical Enrichment of Young Galaxies Near and Far at z ∼ 0 and 4–10: Fe/O, Ar/O, S/O, and N/O Measurements with a Comparison of Chemical Evolution Models
Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +14 more
We present gas-phase elemental abundance ratios of thirteen local extremely metal-poor galaxies (EMPGs), including our new Keck/LRIS spectroscopy determinations together with 33 James Webb Space Telescope z ∼ 4–10 star-forming galaxies in the literature, and compare chemical evolution models. We develop chemical evolution models with the yields of…
Building the First Galaxies—Chapter 2. Starbursts Dominate the Star Formation Histories of 6 < z < 12 Galaxies
Carniani, Stefano; Bunker, Andrew J.; Stark, Daniel P. +12 more
We use SEDz*—a code designed to chart the star formation histories (SFHs) of 6 < z < 12 galaxies—to analyze the spectral energy distributions (SEDs) of 894 galaxies with deep JWST/NIRCam imaging by JADES in the GOODS-S field. We show how SEDz* matches observed SEDs using stellar-population templates, graphing the contribution of each epoch b…
A Strong He II λ1640 Emitter with an Extremely Blue UV Spectral Slope at z = 8.16: Presence of Population III Stars?
Arrabal Haro, Pablo; Ji, Zhiyuan; Brammer, Gabriel +12 more
Cosmic hydrogen reionization and cosmic production of the first metals are major phase transitions of the Universe occurring during the first billion years after the Big Bang; however, these are still underexplored observationally. Using the JWST/NIRSpec prism spectroscopy, we report the discovery of a sub-L * galaxy at z spec