Search Publications
What Are the Pillars of Reionization? Revising the AGN Luminosity Function at z ∼ 5
Bisigello, Laura; Grazian, Andrea; Boutsia, Konstantina +22 more
In the past, high-z active galactic nuclei (AGNs) were given a minor role as possible drivers of reionization, despite initial evidence in favor of their large space densities at low luminosities by Chandra and the Hubble Space Telescope. Recent observations from JWST are finding relatively large numbers of faint AGNs at z > 4, convincingly con…
JWST MIRI/Medium Resolution Spectrograph (MRS) Observations and Spectral Models of the Underluminous Type Ia Supernova 2022xkq
Suntzeff, N. B.; Wang, L.; Galbany, L. +44 more
We present a JWST mid-infrared (MIR) spectrum of the underluminous Type Ia Supernova (SN Ia) 2022xkq, obtained with the medium-resolution spectrometer on the Mid-Infrared Instrument (MIRI) ∼130 days post-explosion. We identify the first MIR lines beyond 14 µm in SN Ia observations. We find features unique to underluminous SNe Ia, including t…
The Web Epoch of Reionization Lyα Survey (WERLS). I. MOSFIRE Spectroscopy of z ∼ 7–8 Lyα Emitters
Papovich, Casey; Finkelstein, Steven L.; Casey, Caitlin M. +34 more
We present the first results from the Web Epoch of Reionization Lyα Survey (WERLS), a spectroscopic survey of Lyα emission using Keck I/MOSFIRE and LRIS. WERLS targets bright (J < 26) galaxy candidates with photometric redshifts of 5.5 ≲ z ≲ 8 selected from pre-JWST imaging embedded in the Epoch of Reionization (EoR) within three JWST deep fiel…
CANUCS: An Updated Mass and Magnification Model of A370 with JWST
Willott, Chris J.; Rihtaršič, Gregor; Bradač, Maruša +9 more
We present an updated mass and magnification model of galaxy cluster A370 using new NIRCam, NIRISS, and NIRSpec data from the Canadian NIRISS Unbiased Cluster Survey (CANUCS). Using Lenstool and a combination of archival Hubble Space Telescope (HST) and MUSE data with new JWST data as constraints, we derive an improved gravitational lensing model …
A Tale of Two Molecules: The Underprediction of CO2 and Overprediction of PH3 in Late T and Y Dwarf Atmospheric Models
Cushing, Michael C.; Kirkpatrick, J. Davy; Marley, Mark S. +5 more
The sensitivity and spectral coverage of JWST are enabling us to test our assumptions of ultracool dwarf atmospheric chemistry, especially with regards to the abundances of phosphine (PH3) and carbon dioxide (CO2). In this paper, we use Near Infrared Spectrograph PRISM spectra (∼0.8‑5.5 µm, R ∼ 100) of four late T and Y…
Orbital Torus Imaging: Acceleration, Density, and Dark Matter in the Galactic Disk Measured with Element Abundance Gradients
Hogg, David W.; Price-Whelan, Adrian M.; Ness, Melissa K. +5 more
Under the assumption of a simple and time-invariant gravitational potential, many Galactic dynamics techniques infer the milky Way's mass and dark matter distributions from stellar kinematic observations. These methods typically rely on parameterized potential models of the Galaxy and must take into account nontrivial survey selection effects, bec…
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…