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Sulfur Dioxide and Other Molecular Species in the Atmosphere of the Sub-Neptune GJ 3470 b
DOI: 10.3847/2041-8213/ad55e9 Bibcode: 2024ApJ...970L..10B

Fortney, Jonathan J.; Henry, Gregory W.; Bell, Taylor J. +13 more

We report observations of the atmospheric transmission spectrum of the sub-Neptune exoplanet GJ 3470 b taken using the Near-Infrared Camera on JWST. Combined with two archival Hubble Space Telescope/Wide-Field Camera 3 transit observations and 15 archival Spitzer transit observations, we detect water, methane, sulfur dioxide, and carbon dioxide in…

2024 The Astrophysical Journal
Gaia eHST JWST 21
Uncovering a Massive z 7.7 Galaxy Hosting a Heavily Obscured Radio-loud Active Galactic Nucleus Candidate in COSMOS-Web
DOI: 10.3847/2041-8213/ad11ee Bibcode: 2024ApJ...961L..25L

Casey, Caitlin M.; Chworowsky, Katherine; Hutchison, Taylor A. +47 more

In this Letter, we report the discovery of the highest redshift, heavily obscured, radio-loud (RL) active galactic nucleus (AGN) candidate selected using JWST NIRCam/MIRI, mid-IR, submillimeter, and radio imaging in the COSMOS-Web field. Using multifrequency radio observations and mid-IR photometry, we identify a powerful, RL, growing supermassive…

2024 The Astrophysical Journal
eHST JWST 21
The On-axis Jetted Tidal Disruption Event AT2022cmc: X-Ray Observations and Broadband Spectral Modeling
DOI: 10.3847/1538-4357/ad2b6b Bibcode: 2024ApJ...965...39Y

Kulkarni, S. R.; Cenko, S. Bradley; Gezari, Suvi +5 more

AT2022cmc was recently reported as the first on-axis jetted tidal disruption event (TDE) discovered in the last decade, and the fourth on-axis jetted TDE candidate known so far. In this work, we present NuSTAR hard X-ray (3–30 keV) observations of AT2022cmc, as well as soft X-ray (0.3–6 keV) observations obtained by NICER, Swift, and XMM-Newton. O…

2024 The Astrophysical Journal
XMM-Newton 21
Apache Point Observatory (APO)/SMARTS Flare Star Campaign Observations. I. Blue Wing Asymmetries in Chromospheric Lines during Mid-M-Dwarf Flares from Simultaneous Spectroscopic and Photometric Observation Data
DOI: 10.3847/1538-4357/ad062f Bibcode: 2024ApJ...961..189N

Hamaguchi, Kenji; Notsu, Yuta; Kowalski, Adam F. +12 more

We conducted the time-resolved simultaneous optical spectroscopic and photometric observations of mid-M-dwarf flare stars YZ CMi, EV Lac, and AD Leo. Spectroscopic observations were obtained using Apache Point Observatory 3.5 m and Small and Moderate Aperture Research Telescope System 1.5 m telescopes during 31 nights. Among the 41 detected flares…

2024 The Astrophysical Journal
Gaia 21
Resolved Measurements of the CO-to-H2 Conversion Factor in 37 Nearby Galaxies
DOI: 10.3847/1538-4357/ad23ed Bibcode: 2024ApJ...964...18C

Sandstrom, Karin M.; Bolatto, Alberto D.; Leroy, Adam K. +6 more

We measure the CO-to-H2 conversion factor (α CO) in 37 galaxies at 2 kpc resolution, using the dust surface density inferred from far-infrared emission as a tracer of the gas surface density and assuming a constant dust-to-metal ratio. In total, we have ∼790 and ∼610 independent measurements of α CO for CO (2–1) an…

2024 The Astrophysical Journal
Herschel 21
Statistics for Galaxy Outflows at z ∼ 6–9 with Imaging and Spectroscopic Signatures Identified with JWST/NIRCam and NIRSpec Data
DOI: 10.3847/1538-4357/ad47f4 Bibcode: 2024ApJ...970...19Z

Ono, Yoshiaki; Ouchi, Masami; Harikane, Yuichi +5 more

We present statistics of z ∼ 6–9 galaxy outflows indicated by spatially extended gas emission and broad lines. With a total of 61 spectroscopically confirmed galaxies at z ∼ 6–9 in the JWST CEERS, GLASS, and ERO data, we find four galaxies with [O III] + Hβ ionized gas emission significantly extended beyond the kiloparsec-scale stellar components …

2024 The Astrophysical Journal
JWST 20
The JWST Resolved Stellar Populations Early Release Science Program. IV. The Star Formation History of the Local Group Galaxy WLM
DOI: 10.3847/1538-4357/ad1105 Bibcode: 2024ApJ...961...16M

Gennaro, Mario; Dolphin, Andrew E.; Skillman, Evan D. +23 more

We present the first star formation history (SFH) and age-metallicity relation (AMR) derived from resolved stellar populations imaged with the JWST NIRCam instrument. The target is the Local Group star-forming galaxy WLM at 970 kpc. The depth of the color-magnitude diagram (CMD) reaches below the oldest main sequence turnoff with a signal-to-noise…

2024 The Astrophysical Journal
eHST JWST 20
Discovery and Characterization of Two Ultrafaint Dwarfs outside the Halo of the Milky Way: Leo M and Leo K
DOI: 10.3847/1538-4357/ad429b Bibcode: 2024ApJ...967..161M

Dolphin, Andrew E.; Cohen, Roger E.; Buckley, Matthew R. +4 more

We report the discovery of two ultrafaint dwarf galaxies, Leo M and Leo K, that lie outside the halo of the Milky Way (MW). Using Hubble Space Telescope imaging of the resolved stars, we create color–magnitude diagrams reaching the oldest main-sequence turnoff of each system and (i) fit for structural parameters of the galaxies; (ii) measure their…

2024 The Astrophysical Journal
eHST 20
MINDS. JWST/MIRI Reveals a Dynamic Gas-rich Inner Disk inside the Cavity of SY Cha
DOI: 10.3847/1538-4357/ad1393 Bibcode: 2024ApJ...962....8S

Henning, Thomas; Waters, L. B. F. M.; Güdel, Manuel +23 more

SY Cha is a T Tauri star surrounded by a protoplanetary disk with a large cavity seen in the millimeter continuum but has the spectral energy distribution of a full disk. Here we report the first results from JWST/Mid-InfraRed Instrument (MIRI) Medium Resolution Spectrometer (MRS) observations taken as part of the MIRI mid-INfrared Disk Survey (MI…

2024 The Astrophysical Journal
JWST 20
A Robust Study of High-redshift Galaxies: Unsupervised Machine Learning for Characterizing Morphology with JWST up to z ∼ 8
DOI: 10.3847/1538-4357/ad17b8 Bibcode: 2024ApJ...962..164T

Bamford, S. P.; Conselice, C. J.; Tohill, C. +4 more

Galaxy morphologies provide valuable insights into their formation processes, tracing the spatial distribution of ongoing star formation and encoding signatures of dynamical interactions. While such information has been extensively investigated at low redshift, it is crucial to develop a robust system for characterizing galaxy morphologies at earl…

2024 The Astrophysical Journal
eHST JWST 20