Search Publications
New 511 keV Line Data Provide Strongest sub-GeV Dark Matter Constraints
Silk, Joseph; De la Torre Luque, Pedro; Balaji, Shyam
We explore the 511 keV emission associated with sub-GeV dark matter (DM) particles that can produce electron–positron pairs and form positronium after thermalizing. We use ∼16 yr of data from the Spectrometer on INTEGRAL to constrain DM properties, including the full positron propagation and losses, and the suppression of free electron density awa…
JWST NIRSpec High-resolution Spectroscopy of MACS0647–JD at z = 10.167: Resolved [O II] Doublet and Electron Density in an Early Galaxy
Hutchison, Taylor A.; Larson, Rebecca L.; Conselice, Christopher J. +26 more
We present JWST/NIRSpec high-resolution G395H/F290LP spectroscopy of MACS0647‑JD, a gravitationally lensed galaxy merger at z = 10.167. The new spectroscopy, which is acquired for the two lensed images (JD1 and JD2), detects and resolves emission lines in the rest-frame ultraviolet and blue optical, including the resolved [O II] λ λ3726, 3729 doub…
The Faint Satellite System of NGC 253: Insights into Low-density Environments and No Satellite Plane
Caldwell, Nelson; Strader, Jay; Seth, Anil C. +12 more
We have conducted a systematic search around the Milky Way (MW) analog NGC 253 (D = 3.5 Mpc), as a part of the Panoramic Imaging Survey of Centaurus and Sculptor (PISCeS)—a Magellan+Megacam survey to identify dwarfs and other substructures in resolved stellar light around MW-mass galaxies outside of the Local Group. In total, NGC 253 has five sate…
The Mira Distance to M101 and a 4% Measurement of H 0
Casertano, Stefano; Riess, Adam G.; Zakamska, Nadia L. +8 more
The giant spiral galaxy M101 is host to the nearest recent Type Ia supernova (SN 2011fe) and thus has been extensively monitored in the near-infrared to study the late-time light curve of the SN. Leveraging this existing baseline of observations, we derive the first Mira-based distance to M101 by discovering and classifying a sample of 211 Miras w…
The Red Supergiant Progenitor of Type II Supernova 2024ggi
Wang, Xiaofeng; Zhang, Jujia; Mo, Jun +8 more
We present a detailed analysis of the progenitor and its local environment for the recently discovered Type II supernova (SN) 2024ggi at a distance of about 6.7 Mpc, by utilizing the pre-explosion images from the Hubble Space Telescope and Spitzer Space Telescope. The progenitor is identified as a red bright variable star, with absolute F814W-band…
The High-Redshift Gas-Phase Mass–Metallicity Relation in FIRE-2
Faucher-Giguère, Claude-André; Hayward, Christopher C.; Feldmann, Robert +2 more
The unprecedented infrared spectroscopic capabilities of JWST have provided high-quality interstellar medium metallicity measurements and enabled characterization of the gas-phase mass–metallicity relation (MZR) for galaxies at z ≳ 5 for the first time. We analyze the gas-phase MZR and its evolution in a high-redshift suite of FIRE-2 cosmological …
Morphology of Galaxies in JWST Fields: Initial Distribution and Evolution of Galaxy Morphology
Hwang, Ho Seong; Lee, Jeong Hwan; Park, Changbom +1 more
A recent study from the Horizon Run 5 (HR5) cosmological simulation has predicted that galaxies with
CECILIA: Direct O, N, S, and Ar Abundances in Q2343-D40, a Galaxy at z ∼ 3
Rudie, Gwen C.; Strom, Allison L.; Trainor, Ryan F. +3 more
Measurements of chemical abundances in high-z star-forming (SF) galaxies place important constraints on the enrichment histories of galaxies and the physical conditions in the early Universe. The James Webb Space Telescope (JWST) is beginning to enable direct chemical abundance measurements in galaxies at z > 2 via the detection of the faint T …
No Thick Atmosphere on the Terrestrial Exoplanet Gl 486b
Eastman, Jason D.; Bean, Jacob L.; Zhang, Michael +8 more
A primary science goal for JWST is to detect and characterize the atmospheres of terrestrial planets orbiting M dwarfs (M-Earths). The existence of atmospheres on M-Earths is highly uncertain because their host stars' extended history of high X-ray and ultraviolet irradiation may act to completely remove their atmospheres. We present two JWST seco…
Active Galactic Nuclei and Host Galaxies in COSMOS-Web. I. NIRCam Images, Point-spread-function Models and Initial Results on X-Ray-selected Broad-line AGNs at 0.35 ≲ z ≲ 3.5
Shen, Yue; Zhuang, Ming-Yang; Li, Junyao
We present detailed and comprehensive data reduction and point-spread-function (PSF) model construction for all public JWST NIRCam imaging data from the COSMOS-Web treasury program (up to 2023 June, totaling 0.28 deg2). We show that the NIRCam PSF has significant short-timescale temporal variations and random spatial variations in all f…