Search Publications
CATS: The Hubble Constant from Standardized TRGB and Type Ia Supernova Measurements
Li, S.; Dhawan, S.; Anderson, R. I. +7 more
The tip of the red giant branch (TRGB) provides a luminous standard candle for constructing distance ladders to measure the Hubble constant. In practice, its measurements via edge-detection response (EDR) are complicated by the apparent fuzziness of the tip and the multipeak landscape of the EDR. Previously, we optimized an unsupervised algorithm,…
Precision Modeling of JWST's First Cluster Lens SMACS J0723.3-7327
Mahler, Guillaume; Richard, Johan; Kneib, Jean-Paul +12 more
Exploiting the fundamentally achromatic nature of gravitational lensing, we present a lens model for the massive galaxy cluster SMACS J0723.3-7323 (SMACS J0723; z = 0.388) that significantly improves upon earlier work. Building on strong-lensing constraints identified in prior Hubble Space Telescope (HST) observations, the mass model utilizes 21 m…
Sizes and Mass Profiles of Candidate Massive Galaxies Discovered by JWST at 7 < z < 9: Evidence for Very Early Formation of the Central 100 pc of Present-day Ellipticals
Labbé, Ivo; van Dokkum, Pieter; Bezanson, Rachel +8 more
The first JWST data revealed an unexpected population of red galaxies that appear to have redshifts of z ~ 7-9 and high masses of M * ≳ 1010 M ☉. Here we fit Sérsic profiles to the F200W NIRCam images of the 13 massive galaxy candidates of Labbé et al., to determine their structural parameters. Satisfactory fits we…
Far-ultraviolet to Near-infrared Observations of SN 2023ixf: A High-energy Explosion Engulfed in Complex Circumstellar Material
Kawabata, Koji S.; Pathak, Utkarsh; Kumar, Brajesh +13 more
We present early-phase panchromatic photometric and spectroscopic coverage spanning the far-ultraviolet to near-infrared regime of the nearest hydrogen-rich core-collapse supernova (SN) in the last 25 yr, SN 2023ixf. We observe early "flash" features in the optical spectra due to confined dense circumstellar material (CSM). We observe high-ionizat…
Early Results From GLASS-JWST. XII. The Morphology of Galaxies at the Epoch of Reionization
Vulcani, B.; Treu, T.; Castellano, M. +23 more
Star-forming galaxies can exhibit strong morphological differences between the rest-frame far-UV and optical, reflecting inhomogeneities in star formation and dust attenuation. We exploit deep, high-resolution, NIRCAM seven-band observations to take a first look at the morphology of galaxies in the epoch of reionization (z > 7), and its variati…
JWST Reveals Excess Cool Water near the Snow Line in Compact Disks, Consistent with Pebble Drift
Zhang, Ke; Pascucci, Ilaria; Banzatti, Andrea +19 more
Previous analyses of mid-infrared water spectra from young protoplanetary disks observed with the Spitzer-IRS found an anticorrelation between water luminosity and the millimeter dust disk radius observed with ALMA. This trend was suggested to be evidence for a fundamental process of inner disk water enrichment proposed decades ago to explain some…
Crowded No More: The Accuracy of the Hubble Constant Tested with High-resolution Observations of Cepheids by JWST
Casertano, Stefano; Dolphin, Andrew; Riess, Adam G. +7 more
High-resolution James Webb Space Telescope (JWST) observations can test confusion-limited Hubble Space Telescope (HST) observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWST NIRCAM observations in two epochs and three filters of >320 Cepheids in NGC 4258 (which …
JWST Reveals a Possible z ∼ 11 Galaxy Merger in Triply Lensed MACS0647–JD
Finkelstein, Steven L.; Hutchison, Taylor A.; Larson, Rebecca L. +63 more
MACS0647–JD is a triply lensed z ∼ 11 galaxy originally discovered with the Hubble Space Telescope. The three lensed images are magnified by factors of ∼8, 5, and 2 to AB mag 25.1, 25.6, and 26.6 at 3.5 µm. The brightest is over a magnitude brighter than other galaxies recently discovered at similar redshifts z > 10 with JWST. Here, we re…
A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): A First Look at the Rest-frame Optical Spectra of z > 6.5 Quasars Using JWST
Hennawi, Joseph F.; Shen, Yue; Strauss, Michael A. +53 more
Studies of rest-frame optical emission in quasars at z > 6 have historically been limited by the wavelengths accessible by ground-based telescopes. The James Webb Space Telescope (JWST) now offers the opportunity to probe this emission deep into the reionization epoch. We report the observations of eight quasars at z > 6.5 using the JWST/NIR…
Double Trouble: Two Transits of the Super-Earth GJ 1132 b Observed with JWST NIRSpec G395H
Sing, David K.; Lustig-Yaeger, Jacob; Fu, Guangwei +19 more
The search for rocky planet atmospheres with JWST has focused on planets transiting M dwarfs. Such planets have favorable planet-to-star size ratios, enhancing the amplitude of atmospheric features. Since the expected signal strength of atmospheric features is similar to the single-transit performance of JWST, multiple observations are required to…