Search Publications
Insights into Galaxy Morphology and Star Formation: Unveiling Filamentary Structures around an Extreme Overdensity at z ∼ 1.5 Traced by [O II] Emitters
Koyama, Yusei; Kodama, Tadayuki; Faisst, Andreas +3 more
We explore the morphological features and star formation activities of [O II] emitters in the COSMOS UltraDeep field at z ∼ 1.5 using JWST NIRCam data from the COSMOS-Web survey and Subaru Hyper Suprime-Cam. We also report the discovery of large filamentary structures traced by [O II] emitters surrounding an extremely overdense core with a galaxy …
Discovery of a Relativistic Stripped-envelope Type Ic-BL Supernova at z = 2.83 with JWST
Maiolino, R.; Fox, O. D.; Rest, A. +26 more
We present James Webb Space Telescope (JWST) NIRCam and NIRSpec observations of a Type Ic supernova (SN Ic) and its host galaxy (JADES-GS+53.13533-27.81457) at z = 2.83. This SN (named SN 2023adta) was identified in deep JWST/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Follow-up observations with JWST/NIRSpec p…
oMEGACat. III. Multiband Photometry and Metallicities Reveal Spatially Well-mixed Populations within ω Centauri's Half-light Radius
Dreizler, S.; Milone, A. P.; Wang, Z. +15 more
ω Centauri, the most massive globular cluster in the Milky Way, has long been suspected to be the stripped nucleus of a dwarf galaxy that fell into the Galaxy a long time ago. There is considerable evidence for this scenario including a large spread in metallicity and an unusually large number of distinct subpopulations seen in photometric studies…
New Horizons Venetia Burney Student Dust Counter Observes Higher than Expected Fluxes Approaching 60 au
Singer, Kelsi N.; Stern, S. Alan; Verbiscer, Anne +8 more
The NASA New Horizons Venetia Burney Student Dust Counter (SDC) measures dust particle impacts along the spacecraft's flight path for grains with mass ≥10‑12 g, mapping out their spatial density distribution. We present the latest SDC dust density, size distribution, and flux measurements through 55 au and compare them to numerical mode…
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 …