Search Publications
The JWST Early-release Science Program for Direct Observations of Exoplanetary Systems II: A 1 to 20 µm Spectrum of the Planetary-mass Companion VHS 1256-1257 b
Henning, Thomas; Fortney, Jonathan J.; Carter, Aarynn L. +108 more
We present the highest fidelity spectrum to date of a planetary-mass object. VHS 1256 b is a <20 M Jup widely separated (~8″, a = 150 au), young, planetary-mass companion that shares photometric colors and spectroscopic features with the directly imaged exoplanets HR 8799c, d, and e. As an L-to-T transition object, VHS 1256 b exists …
The impact of UV variability on the abundance of bright galaxies at z ≥ 9
Vogelsberger, Mark; Tacchella, Sandro; Boylan-Kolchin, Michael +2 more
JWST observations have revealed a population of galaxies bright enough that potentially challenge standard galaxy formation models in the Λ cold dark matter (ΛCDM) cosmology. Using a minimal empirical framework, we investigate the influence of variability on the rest-frame ultra-violet (UV) luminosity function of galaxies at z ≥ 9. Our study diffe…
High Tide or Riptide on the Cosmic Shoreline? A Water-rich Atmosphere or Stellar Contamination for the Warm Super-Earth GJ 486b from JWST Observations
Sing, David K.; Lustig-Yaeger, Jacob; Fu, Guangwei +21 more
Planets orbiting M-dwarf stars are prime targets in the search for rocky exoplanet atmospheres. The small size of M dwarfs renders their planets exceptional targets for transmission spectroscopy, facilitating atmospheric characterization. However, it remains unknown whether their host stars' highly variable extreme-UV radiation environments allow …
Gaia Data Release 3. Specific processing and validation of all-sky RR Lyrae and Cepheid stars: The RR Lyrae sample
Szabados, L.; Audard, M.; Andrae, R. +18 more
Context. RR Lyrae stars are excellent tracers of the oldest stars (ages ≳ 9-10 Gyr) and standard candles for measuring the distance to stellar systems that are mainly composed of an old stellar population. The Gaia Third Data Release (DR3) publishes a catalogue of full-sky RR Lyrae stars observed during the initial 34 months of science operations.…
Early Results from GLASS-JWST. XIV. A Spectroscopically Confirmed Protocluster 650 Million Years after the Big Bang
Santini, Paola; Calabrò, Antonello; Castellano, Marco +39 more
We present the spectroscopic confirmation of a protocluster at z = 7.88 behind the galaxy cluster Abell 2744 (hereafter A2744-z7p9OD). Using JWST NIRSpec, we find seven galaxies within a projected radius of 60 kpc. Although the galaxies reside in an overdensity around ≳20× greater than a random volume, they do not show strong Lyα emission. We plac…
Momentum transfer from the DART mission kinetic impact on asteroid Dimorphos
Zinzi, Angelo; Cheng, Andrew F.; Dall'Ora, Massimo +66 more
The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of the binary asteroid (65803) Didymos, at 23:14 UTC on 26 September 2022 as a planetary defence test1. DART was the first hypervelocity impact experiment on an asteroid at size and velocity scales relevant to planeta…
Excitation and Ionization Properties of Star-forming Galaxies at z = 2.0-9.3 with JWST/NIRSpec
Shapley, Alice E.; Reddy, Naveen A.; Sanders, Ryan L. +2 more
We utilize medium-resolution JWST/NIRSpec observations of 164 galaxies at z = 2.0-9.3 from the Cosmic Evolution Early Release Science (CEERS) survey to investigate the evolution of the excitation and ionization properties of galaxies at high redshifts. Our results represent the first statistical constraints on the evolution of the [O III]/Hβ versu…
The MillenniumTNG project: the galaxy population at z ≥ 8
Springel, Volker; Hernquist, Lars; Pakmor, Rüdiger +11 more
The early release science results from JWST have yielded an unexpected abundance of high-redshift luminous galaxies that seems to be in tension with current theories of galaxy formation. However, it is currently difficult to draw definitive conclusions form these results as the sources have not yet been spectroscopically confirmed. It is in any ca…
The Target-selection Pipeline for the Dark Energy Spectroscopic Instrument
Myers, Adam D.; Bailey, Stephen; Palanque-Delabrouille, Nathalie +51 more
In 2021 May, the Dark Energy Spectroscopic Instrument (DESI) began a 5 yr survey of approximately 50 million total extragalactic and Galactic targets. The primary DESI dark-time targets are emission line galaxies, luminous red galaxies, and quasars. In bright time, DESI will focus on two surveys known as the Bright Galaxy Survey and the Milky Way …
A magnified compact galaxy at redshift 9.51 with strong nebular emission lines
Koekemoer, Anton M.; Treu, Tommaso; Broadhurst, Tom +21 more
Ultraviolet light from early galaxies is thought to have ionized gas in the intergalactic medium. However, there are few observational constraints on this epoch because of the faintness of those galaxies and the redshift of their optical light into the infrared. We report the observation, in JWST imaging, of a distant galaxy that is magnified by g…