Search Publications
A Comprehensive Metallicity Analysis of J0332‑3557: Establishing a z ∼ 4 Anchor for Direct Gas Metallicity and C/O Abundance Investigations
Skillman, Evan D.; Erb, Dawn K.; James, Bethan L. +4 more
We provide one of the most comprehensive metallicity studies at z ∼ 4 by analyzing the UV/optical Hubble Space Telescope photometry and rest-frame Very Large Telescope (VLT)/FORS2 UV and VLT/XSHOOTER optical spectra of J0332‑3557, a gravitationally lensed galaxy magnified by a factor of 20. With a 5σ detection of the auroral O III] λ1666 line, we …
The R-Process Alliance: 2MASS J22132050–5137385, the Star with the Highest-known r-process Enhancement at [Eu/Fe] = +2.45
Beers, Timothy C.; Placco, Vinicius M.; Hattori, Kohei +6 more
We present stellar parameters and chemical abundances of 47 elements detected in the bright (V = 11.63) very metal-poor ([Fe/H] = ‑2.20 ± 0.12) star 2MASS J22132050‑5137385. We observed this star using the Magellan Inamori Kyocera Echelle spectrograph as part of ongoing work by the R-Process Alliance. The spectrum of 2MASS J22132050‑5137385 exhibi…
New Synoptic Observations of the Cosmic Optical Background with New Horizons
Singer, Kelsi N.; Stern, S. Alan; Weaver, Harold A. +11 more
We obtained New Horizons LORRI images to measure the cosmic optical background (COB) intensity integrated over 0.4 µm ≲ λ ≲ 0.9 µm. The survey comprises 16 high-Galactic-latitude fields selected to minimize scattered diffuse Galactic light (DGL) from the Milky Way, as well as scattered light from bright stars. This work supersedes an e…
Comprehensive High-resolution Chemical Spectroscopy of Barnard's Star with SPIRou
Carmona, Andrés; Gaidos, Eric; Vandal, Thomas +17 more
Determination of fundamental parameters of stars impacts all fields of astrophysics, from galaxy evolution to constraining the internal structure of exoplanets. This paper presents a detailed spectroscopic analysis of Barnard's star (otherwise known as Gl 699) that compares an exceptionally high-quality (an average signal-to-noise ratio of ∼1000 i…
A Young Super Star Cluster Powering a Nebula of Retained Massive Star Ejecta
Pascale, Massimo; Dai, Liang
We suggest that "Godzilla" of the lensed Sunburst galaxy (z = 2.37) is a young super star cluster powering a nebula of gravitationally trapped stellar ejecta. Employing Hubble Space Telescope photometry and spectroscopy from the Very Large Telescope (VLT) MUSE and VLT/X-Shooter, we infer the physical and chemical properties of the cluster and nebu…
Using JWST Transits and Occultations to Determine ∼1% Stellar Radii and Temperatures of Low-mass Stars
Kirk, James; Eastman, Jason D.; Mahajan, Alexandra S.
Using JWST observations of a primary transit and two secondary eclipses for GJ 1214b, we determine an eccentricity that is more precise than a decade of HARPS data, which enables us to measure the stellar density to 2.62%. Coupled with a prior on the stellar mass from a dynamically calibrated K S–M * relation, we determine R …
Modeling and Subtracting Diffuse Cluster Light in JWST Images: A Relation between the Spatial Distribution of Globular Clusters, Dwarf Galaxies, and Intracluster Light in the Lensing Cluster SMACS 0723
Willott, Chris J.; Harshan, Anishya; Martis, Nicholas S. +11 more
We present a methodology for modeling and removing light from cluster galaxies and intracluster light (ICL) from James Webb Space Telescope images of gravitational lensing clusters. We apply our method to Webb's First Deep Field the SMACS 0723 Early Release Observations and use the ICL-subtracted images to select a sample of globular clusters (GCs…
Galactic Chemical Evolution Models Favor an Extended Type Ia Supernova Delay-time Distribution
Johnson, Jennifer A.; Johnson, James W.; Dubay, Liam O.
Type Ia supernovae (SNe Ia) produce most of the Fe-peak elements in the Universe and therefore are a crucial ingredient in galactic chemical evolution models. SNe Ia do not explode immediately after star formation, and the delay-time distribution (DTD) has not been definitively determined by supernova surveys or theoretical models. Because the DTD…
ReveaLLAGN 0: First Look at JWST MIRI Data of Sombrero and NGC 1052
Kirkpatrick, Allison; Trump, Jonathan R.; Lützgendorf, Nora +28 more
We present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGNs. We focus on two observations with the Mid-Infrared Instrument (MIRI)'s Medium-Resolution Spectrometer of the nuclei of NGC 1052 and Sombrero (NGC 4594/M104). We also compare these data to public JWST data…
Lyα Emission Line Profiles of Extreme [O III]- emitting Galaxies at z ≳ 2: Implications for Lyα Visibility in the Reionization Era
Tang, Mengtao; Stark, Daniel P.; Ellis, Richard S. +4 more
JWST observations have recently begun delivering the first samples of Lyα velocity profile measurements at z > 6, opening a new window into the reionization process. Interpretation of z ≳ 6 line profiles is currently stunted by limitations in our knowledge of the intrinsic Lyα profile (before encountering the intergalactic medium (IGM)) of the …