Search Publications
GA-NIFS: an extremely nitrogen-loud and chemically stratified galaxy at z 5.55
Charlot, Stéphane; Übler, Hannah; D'Eugenio, Francesco +11 more
We report the chemical abundance pattern of GS_3073, a galaxy hosting an overmassive active black hole at
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
The SN 2023ixf Progenitor in M101. II. Properties
Van Dyk, Schuyler D.; Matheson, Thomas; Howell, Steve B. +12 more
We follow our first paper with an analysis of the ensemble of the extensive preexplosion ground- and space-based infrared observations of the red supergiant (RSG) progenitor candidate for the nearby core-collapse supernova SN 2023ixf in Messier 101, together with optical data prior to the explosion obtained with the Hubble Space Telescope (HST). W…
JWST spectroscopy of z 5-8 UV-selected galaxies: new constraints on the evolution of the Ly α escape fraction in the reionization era
Charlot, Stéphane; Chen, Zuyi; Tang, Mengtao +5 more
We describe JWST/NIRSpec prism measurements of Ly α emission in z ≳ 5 galaxies. We identify Ly α detections in 10 out of 69 galaxies with robust rest-optical emission-line redshift measurements at 5 ≤ z < 7 in the Cosmic Evolution Early Release Science (CEERS) and DDT-2750 observations of the Extended Groth Strip field. Galaxies at z ≃ 6 with f…
Peering into cosmic reionization: Lyα visibility evolution from galaxies at z = 4.5-8.5 with JWST
Hu, W.; Kartaltepe, J. S.; Dickinson, M. +30 more
The resonant scattering interaction between Lyα photons and neutral hydrogen implies that a partially neutral intergalactic medium has the ability to significantly impact the detectability of Lyα emission in galaxies. Thus, the redshift evolution of the Lyα equivalent width distribution of galaxies offers a key observational probe of the degree of…
A secondary atmosphere on the rocky exoplanet 55 Cancri e
Knutson, Heather A.; Hu, Renyu; Dragomir, Diana +14 more
Characterizing rocky exoplanets is a central aim of astronomy, and yet the search for atmospheres on rocky exoplanets has so far resulted in either tight upper limits on the atmospheric mass1-3 or inconclusive results4-6. The 1.95REarth and 8.8MEarth planet 55 Cancri e (abbreviated 55 Cnc e), with a pred…
Lensed Type Ia Supernova "Encore" at z = 2: The First Instance of Two Multiply Imaged Supernovae in the Same Host Galaxy
Pérez-Fournon, I.; Fox, O. D.; Diego, J. M. +60 more
A bright (m F150W,AB = 24 mag), z = 1.95 supernova (SN) candidate was discovered in JWST/NIRCam imaging acquired on 2023 November 17. The SN is quintuply imaged as a result of strong gravitational lensing by a foreground galaxy cluster, detected in three locations, and remarkably is the second lensed SN found in the same host galaxy. Th…
UNCOVER: JWST Spectroscopy of Three Cold Brown Dwarfs at Kiloparsec-scale Distances
Nanayakkara, Themiya; van Dokkum, Pieter; Fujimoto, Seiji +19 more
We report JWST/NIRSpec spectra of three distant T-type brown dwarfs identified in the Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization (UNCOVER) survey of the Abell 2744 lensing field. One source was previously reported as a candidate T dwarf on the basis of NIRCam photometry, while two sources were initially identified a…
JWST and ALMA Multiple-line Study in and around a Galaxy at z = 8.496: Optical to Far-Infrared Line Ratios and the Onset of an Outflow Promoting Ionizing Photon Escape
Ouchi, Masami; Koekemoer, Anton M.; Richard, Johan +33 more
We present Atacama Large Millimeter/submillimeter Array (ALMA) deep spectroscopy for a lensed galaxy at z spec = 8.496 with $\mathrm{log}({M}_{\mathrm{star}}/{M}_{\odot })\sim 7.8$ whose optical nebular lines and stellar continuum are detected by JWST/NIRSpec and NIRCam Early Release Observations in the field of SMACS J0723.3–7327. Our …
Strong gravitational lensing's 'external shear' is not shear
Koekemoer, Anton M.; Mahler, Guillaume; Frye, Brenda L. +20 more
The distribution of mass in galaxy-scale strong gravitational lenses is often modelled as an elliptical power-law plus 'external shear', which notionally accounts for neighbouring galaxies and cosmic shear along our line of sight. A small amount of external shear could come from these sources, but we show that the vast majority does not. Except in…