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CEERS Key Paper. VIII. Emission-line Ratios from NIRSpec and NIRCam Wide-Field Slitless Spectroscopy at z > 2
DOI: 10.3847/1538-4357/ad1520 Bibcode: 2024ApJ...962..195B

Papovich, Casey; Yang, Guang; Finkelstein, Steven L. +37 more

We use James Webb Space Telescope Near-Infrared Camera Wide Field Slitless Spectroscopy (NIRCam WFSS) and the Near-Infrared spectrograph (NIRSpec) in the Cosmic Evolution Early Release survey to measure rest-frame optical emission-line ratios of 155 galaxies at z > 2. The blind NIRCam grism observations include a sample of galaxies with bright …

2024 The Astrophysical Journal
eHST JWST 25
Discovery of a Collimated Jet from the Low-luminosity Protostar IRAS 16253‑2429 in a Quiescent Accretion Phase with the JWST
DOI: 10.3847/2041-8213/ad1de3 Bibcode: 2024ApJ...962L..16N

Manoj, P.; Narang, Mayank; Bourke, Tyler L. +36 more

Investigating Protostellar Accretion (IPA) is a JWST Cycle 1 GO program that uses NIRSpec integral field units and MIRI Medium Resolution Spectrograph to obtain 2.9–28 µm spectral cubes of young, deeply embedded protostars with luminosities of 0.2–10,000 L and central masses of 0.15–12 M . In this Letter, we report t…

2024 The Astrophysical Journal
JWST 25
Modeling of Long-term Afterglow Counterparts to Gravitational Wave Events: The Full View of GRB 170817A
DOI: 10.3847/1538-4357/ad6a14 Bibcode: 2024ApJ...975..131R

Piro, Luigi; Ryan, Geoffrey; O'Connor, Brendan +3 more

The arrival of gravitational wave astronomy and a growing number of time-domain-focused observatories are set to lead to an increasing number of detections of short gamma-ray bursts (GRBs) launched with a moderate inclination to Earth. Being nearby events, these are also prime candidates for very long-term follow-up campaigns and very long-baselin…

2024 The Astrophysical Journal
eHST 25
CLASSY. VIII. Exploring the Source of Ionization with UV Interstellar Medium Diagnostics in Local High-z Analogs
DOI: 10.3847/1538-4357/ad1033 Bibcode: 2024ApJ...962...95M

Kewley, Lisa J.; Ravindranath, Swara; Wilkins, Stephen M. +27 more

In the current JWST era, rest-frame UV spectra play a crucial role in enhancing our understanding of the interstellar medium (ISM) and stellar properties of the first galaxies in the epoch of reionization (z > 6). Here, we compare well-known and reliable optical diagrams sensitive to the main ionization source (i.e., star formation, SF; active …

2024 The Astrophysical Journal
eHST 25
New Mass and Radius Constraints on the LHS 1140 Planets: LHS 1140 b Is either a Temperate Mini-Neptune or a Water World
DOI: 10.3847/2041-8213/ad1691 Bibcode: 2024ApJ...960L...3C

Wade, Gregg A.; Dang, Lisa; Cowan, Nicolas B. +43 more

The two-planet transiting system LHS 1140 has been extensively observed since its discovery in 2017, notably with Spitzer, HST, TESS, and ESPRESSO, placing strong constraints on the parameters of the M4.5 host star and its small temperate exoplanets, LHS 1140 b and c. Here, we reanalyze the ESPRESSO observations of LHS 1140 with the novel line-by-…

2024 The Astrophysical Journal
Gaia eHST 25
Muted Features in the JWST NIRISS Transmission Spectrum of Hot Neptune LTT 9779b
DOI: 10.3847/2041-8213/ad20e4 Bibcode: 2024ApJ...962L..20R

Johnstone, Doug; Dang, Lisa; Cowan, Nicolas B. +13 more

The hot Neptune desert is one of the most sparsely populated regions of the exoplanet parameter space, and atmosphere observations of its few residents can provide insights into how such planets have managed to survive in such an inhospitable environment. Here, we present transmission observations of LTT 9779 b, the only known hot Neptune to have …

2024 The Astrophysical Journal
JWST 25
Clouds and Clarity: Revisiting Atmospheric Feature Trends in Neptune-size Exoplanets
DOI: 10.3847/2041-8213/ad1b5c Bibcode: 2024ApJ...961L..23B

Fortney, Jonathan J.; Mikal-Evans, Thomas; Lothringer, Joshua D. +12 more

Over the last decade, precise exoplanet transmission spectroscopy has revealed the atmospheres of dozens of exoplanets, driven largely by observatories like the Hubble Space Telescope. One major discovery has been the ubiquity of atmospheric aerosols, often blocking access to exoplanet chemical inventories. Tentative trends have been identified, s…

2024 The Astrophysical Journal
eHST JWST 25
Multivariate Predictors of Lyman Continuum Escape. I. A Survival Analysis of the Low-redshift Lyman Continuum Survey
DOI: 10.3847/1538-4357/ad58b9 Bibcode: 2024ApJ...972...92J

Ferguson, Henry C.; Giavalisco, Mauro; Pentericci, Laura +19 more

To understand how galaxies reionized the Universe, we must determine how the escape fraction of Lyman continuum (LyC) photons (f esc) depends on galaxy properties. Using the z ∼ 0.3 Low-redshift Lyman Continuum Survey (LzLCS), we develop and analyze new multivariate predictors of f esc. These predictions use the Cox proportio…

2024 The Astrophysical Journal
eHST 23
LHS 1140 b Is a Potentially Habitable Water World
DOI: 10.3847/2041-8213/ad5204 Bibcode: 2024ApJ...968L..22D

Yang, Jeehyun; Hu, Renyu; Bello-Arufe, Aaron +1 more

LHS 1140 b is a small planet orbiting in the habitable zone of its M4.5V dwarf host. Recent mass and radius constraints have indicated that it has either a thick H2-rich atmosphere or substantial water by mass. Here we present a transmission spectrum of LHS 1140 b between 1.7 and 5.2 µm, obtained using the NIRSpec instrument on JW…

2024 The Astrophysical Journal
JWST 23
Multivariate Predictors of Lyman Continuum Escape. II. Predicting Lyman Continuum Escape Fractions for High-redshift Galaxies
DOI: 10.3847/1538-4357/ad5557 Bibcode: 2024ApJ...973..111J

Ferguson, Henry C.; Giavalisco, Mauro; Pentericci, Laura +19 more

JWST is uncovering the properties of ever-increasing numbers of galaxies at z > 6, during the epoch of reionization. Connecting these observed populations to the process of reionization requires understanding how efficiently they produce Lyman continuum (LyC) photons and what fraction (f esc) of these photons escape into the intergal…

2024 The Astrophysical Journal
eHST 23