Search Publications
Reionization and the ISM/Stellar Origins with JWST and ALMA (RIOJA): The Core of the Highest-redshift Galaxy Overdensity at z = 7.88 Confirmed by NIRSpec/JWST
Marques-Chaves, R.; Colina, L.; Fudamoto, Y. +20 more
The protoclusters in the epoch of reionization, traced by galaxy overdensity regions, are ideal laboratories for studying the process of stellar assembly and cosmic reionization. We present the spectroscopic confirmation of the core of the most distant protocluster at z = 7.88, A2744-z7p9OD, with the James Webb Space Telescope NIRSpec integral fie…
The origin and fate of the Gaia phase-space snail
Bovy, Jo; Tremaine, Scott; Frankel, Neige
The Gaia snail is a spiral feature in the distribution of solar-neighbourhood stars in position and velocity normal to the Galactic midplane. The snail probably arises from phase mixing of gravitational disturbances that perturbed the disc in the distant past. The most common hypothesis is that the primary disturbance resulted from a passage of th…
On the Sizes of Ionized Bubbles Around Galaxies During the Reionization Epoch. The Spectral Shapes of the Lyα Emission from Galaxies
Scarlata, Claudia; Hayes, Matthew J.
We develop a new method to determine the distance between a high-redshift galaxy and a foreground screen of atomic hydrogen. In a partially neutral universe, and assuming spherical symmetry, this equates to the radius of an ionized "bubble" (R B) surrounding the galaxy. The method requires an observed Lyα equivalent width, its velocity …
CO or no CO? Narrowing the CO abundance constraint and recovering the H2O detection in the atmosphere of WASP-127 b using SPIRou
Vinatier, Sandrine; Gaidos, Eric; Cowan, Nicolas B. +24 more
Precise measurements of chemical abundances in planetary atmospheres are necessary to constrain the formation histories of exoplanets. A recent study of WASP-127 b, a close-in puffy sub-Saturn orbiting its solar-type host star in 4.2 d, using Hubble Space Telescope (HST) and Spitzer revealed a feature-rich transmission spectrum with strong excess …
Gaia Data Release 3. Validating the classification of variable young stellar object candidates
Gavras, Panagiotis; Ábrahám, Péter; Kóspál, Ágnes +14 more
Context. The Gaia third Data Release (DR3) presents the first catalogue of full-sky variable young stellar object (YSO) candidates observed by the Gaia space telescope during the initial 34 months of science operations.
Aims: Numerous types of variable stars were classified using photometric data collected by Gaia. One of the new classes pres…
JWST CEERS probes the role of stellar mass and morphology in obscuring galaxies
Papovich, Casey; Finkelstein, Steven L.; Buat, Véronique +38 more
In recent years, observations have uncovered a population of massive galaxies that are invisible or very faint in deep optical/near-infrared (near-IR) surveys but brighter at longer wavelengths. However, the nature of these optically dark or faint galaxies (OFGs; one of several names given to these objects) is highly uncertain. In this work, we in…
Distant Echoes of the Milky Way's Last Major Merger
Conroy, Charlie; Ting, Yuan-Sen; Cargile, Phillip A. +9 more
The majority of the Milky Way's stellar halo consists of debris from our galaxy's last major merger, the Gaia-Sausage-Enceladus (GSE). In the past few years, stars from the GSE have been kinematically and chemically studied in the inner 30 kpc of our galaxy. However, simulations predict that accreted debris could lie at greater distances, forming …
JWST's PEARLS: A JWST/NIRCam View of ALMA Sources
Grogin, Norman A.; Hathi, Nimish P.; Holwerda, Benne W. +33 more
We report the results of James Webb Space Telescope/NIRCam observations of 19 (sub)millimeter sources detected by the Atacama Large Millimeter Array (ALMA). The accurate ALMA positions allowed unambiguous identifications of their NIRCam counterparts. Taking gravitational lensing into account, these represent 16 distinct galaxies in three fields an…
Massive dark matter haloes at high redshift: implications for observations in the JWST era
Wang, Kai; Chen, Yangyao; Mo, H. J.
The presence of massive galaxies at high z as recently observed by JWST appears to contradict the current ΛCDM cosmology. Here, we aim to alleviate this tension by incorporating uncertainties from three sources in counting galaxies: cosmic variance, error in stellar mass estimation, and backsplash enhancement. Each of these factors significantly i…
Spectroscopic Time Series Performance of the Mid-infrared Instrument on the JWST
Espinoza, Néstor; Bell, Taylor J.; Bouwman, Jeroen +21 more
We present here the first ever mid-infrared spectroscopic time series observation of the transiting exoplanet L 168-9 b with the Mid-Infrared Instrument (MIRI) on the James Webb Space Telescope. The data were obtained as part of the MIRI commissioning activities, to characterize the performance of the Low Resolution Spectroscopy (LRS) mode for the…