Search Publications
Validation of Elemental and Isotopic Abundances in Late-M Spectral Types with the Benchmark HIP 55507 AB System
Zhang, Yapeng; Do Ó, Clarissa R.; Fitzgerald, Michael P. +48 more
M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which share similar T eff ∼ 2300–2800 K. We present atmospheric analyses for the M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution (R …
Overmassive Black Holes at Cosmic Noon: Linking the Local and the High-redshift Universe
Natarajan, Priyamvada; Siudek, Malgorzata; Pacucci, Fabio +2 more
We report for the first time a sample of 12 supermassive black holes (SMBHs) hosted by low-mass galaxies at cosmic noon, i.e., in a redshift range consistent with the peak of star formation history: z ∼ 1–3. These black holes are 2 orders of magnitude too massive for the stellar content of their hosts when compared with the local relation for acti…
JWST Reveals a Surprisingly High Fraction of Galaxies Being Spiral-like at 0.5 ≤ z ≤ 4
Guo, Yicheng; Martin, Alec; Kuhn, Vicki +3 more
Spiral arms are one of the most important features used to classify the morphology of local galaxies. The cosmic epoch when spiral arms first appeared contains essential clues to the evolution of disk galaxies. In this Letter, we used James Webb Space Telescope images from the Cosmic Evolution Early Release Science Survey to visually identify spir…
JWST Photometric Time-delay and Magnification Measurements for the Triply Imaged Type Ia "SN H0pe" at z = 1.78
Pérez-Fournon, I.; Fox, O. D.; Ryan, R. E. +60 more
Supernova (SN) SN H0pe is a gravitationally lensed, triply imaged, Type Ia SN (SN Ia) discovered in James Webb Space Telescope imaging of the PLCK G165.7+67.0 cluster of galaxies. Well-observed multiply imaged SNe provide a rare opportunity to constrain the Hubble constant (H 0), by measuring the relative time delay between the images a…
JWST Transmission Spectroscopy of HD 209458b: A Supersolar Metallicity, a Very Low C/O, and No Evidence of CH4, HCN, or C2H2
Bean, Jacob L.; Zhang, Michael; Welbanks, Luis +3 more
We present the transmission spectrum of the original transiting hot Jupiter HD 209458b from 2.3 to 5.1 µm as observed with the NIRCam instrument on the James Webb Space Telescope (JWST). Previous studies of HD 209458b's atmosphere have given conflicting results on the abundance of H2O and the presence of carbon- and nitrogen-beari…
Identification of High-redshift Galaxy Overdensities in GOODS-N and GOODS-S
Bunker, Andrew J.; Maiolino, Roberto; Willott, Chris +18 more
We conduct a systematic search for high-redshift galaxy overdensities at 4.9 < z spec < 8.9 in both the Great Observatories Origins Deep Survey (GOODS)-N and GOODS-S fields using James Webb Space Telescope/Near-Infrared Camera (JWST/NIRCam) imaging from the JWST Advanced Deep Extragalactic Survey and JWST Extragalactic Medium-band…
JWST/NIRSpec Observations of Lyman α Emission in Star-forming Galaxies at 6.5 ≲ z ≲ 13
Tang, Mengtao; Stark, Daniel P.; Ellis, Richard S. +2 more
We present an analysis of JWST Lyα spectroscopy of z ≳ 6.5 galaxies, using observations in the public archive covering galaxies in four independent fields: Great Observatories Origins Deep Survey (GOODS)-N, GOODS-S, A2744, and the Extended Groth Strip (EGS). We measure the Lyα emission line properties for a sample of 210 z ≃ 6.5–13 galaxies, with …
The Structure and Morphology of Galaxies during the Epoch of Reionization Revealed by JWST
Ho, Luis C.; Zhuang, Ming-Yang; Li, Ruancun +3 more
We analyze 347 galaxies at redshift 4 < z < 9.5 using JWST observations from the Cosmic Evolution Early Release Science (CEERS) program by simultaneously fitting a two-dimensional parametric model to the seven-filter Near Infrared Camera images to measure the overall structural parameters and quantify the global properties of the galaxies in…
SMILES Initial Data Release: Unveiling the Obscured Universe with MIRI Multiband Imaging
Pérez-González, Pablo G.; Ji, Zhiyuan; Shivaei, Irene +12 more
The James Webb Space Telescope is revolutionizing our view of the Universe through unprecedented sensitivity and resolution in the infrared, with some of the largest gains realized at its longest wavelengths. We present the Systematic Mid-infrared Instrument (MIRI) Legacy Extragalactic Survey (SMILES), an eight-band MIRI survey with Near-Infrared …
JWST/NIRISS Reveals the Water-rich "Steam World" Atmosphere of GJ 9827 d
Fortney, Jonathan J.; MacDonald, Ryan J.; Knutson, Heather A. +30 more
With sizable volatile envelopes but smaller radii than the solar system ice giants, sub-Neptunes have been revealed as one of the most common types of planet in the galaxy. While the spectroscopic characterization of larger sub-Neptunes (2.5–4 R ⊕) has revealed hydrogen-dominated atmospheres, smaller sub-Neptunes (1.6–2.5 R ⊕…