Search Publications
An Atmospheric Retrieval of the Brown Dwarf Gliese 229B
Faherty, Jacqueline K.; Calamari, Emily; Burningham, Ben +6 more
We present results from an atmospheric retrieval analysis of Gl 229B using the Brewster retrieval code. We find the best fit model to be cloud-free, consistent with the T dwarf retrieval work of Line et al.; Zalesky et al. and Gonzales et al. Fundamental parameters (mass, radius, log(L Bol /L Sun), log(g)) determined from our…
Cleaning Our Hazy Lens: Exploring Trends in Transmission Spectra of Warm Exoplanets
Fortney, Jonathan J.; Zhang, Xi; Thorngren, Daniel +4 more
Relatively little is understood about the atmospheric composition of temperate to warm exoplanets (equilibrium temperature T eq < 1000 K), as many of them are found to have uncharacteristically flat transmission spectra. Their flattened spectra are likely due to atmospheric opacity sources such as planet-wide photochemical hazes and …
From Naked Spheroids to Disky Galaxies: How Do Massive Disk Galaxies Shape Their Morphology?
Barro, Guillermo; Pérez-González, Pablo G.; Costantin, Luca +9 more
We investigate the assembly history of massive disk galaxies and describe how they shape their morphology through cosmic time. Using SHARDS and HST data, we modeled the surface brightness distribution of 91 massive galaxies at redshift 0.14 < z ≤ 1 in the wavelength range 0.5-1.6 µm, deriving the uncontaminated spectral energy distributio…
About Metallicity Variations in the Local Galactic Interstellar Medium
Méndez-Delgado, J. E.; Arellano-Córdova, K. Z.; García-Rojas, J. +1 more
In this paper we discuss and confront recent results on metallicity variations in the local interstellar medium, obtained from observations of H II regions and neutral clouds of the Galactic thin disk, and compare them with recent high-quality metallicity determinations of other tracers of the chemical composition of the interstellar medium as B-t…
Measurements of the Hubble Constant with a Two-rung Distance Ladder: Two Out of Three Ain't Bad
Casertano, Stefano; Jones, David O.; Riess, Adam G. +7 more
The three-rung distance ladder, which calibrates Type Ia supernovae (SNe Ia) through stellar distances linked to geometric measurements, provides the highest precision direct measurement of the Hubble constant. In light of the Hubble tension, it is important to test the individual components of the distance ladder. For this purpose, we report a me…
Early Results from GLASS-JWST. VIII. An Extremely Magnified Blue Supergiant Star at Redshift 2.65 in the A2744 Cluster Field
Castellano, Marco; Treu, Tommaso; Frye, Brenda L. +18 more
We report the discovery of an extremely magnified star at redshift z = 2.65 in the James Webb Space Telescope (JWST) NIRISS pre-imaging of the A2744 galaxy-cluster field. The star's background host galaxy lies on a fold caustic of the foreground lens, and the cluster creates a pair of images of the region close to the lensed star. We identified th…
The Local Group Mass in the Light of Gaia
Vasiliev, Eugene; Evans, N. Wyn; Strigari, Louis E. +3 more
High-accuracy proper motions (PMs) of M31 and other Local Group (LG) satellites have now been provided by the Gaia satellite. We revisit the timing argument to compute the total mass M of the LG from the orbit of the Milky Way and M31, allowing for the cosmological constant. We rectify a systematic effect caused by the presence of the Large Magell…
Mapping the Complex Kinematic Substructure in the TW Hya Disk
Andrews, Sean M.; Bae, Jaehan; Bergin, Edwin A. +6 more
We present ALMA observations of CO J = 2 - 1 and CS J = 5 - 4 emission from the disk around TW Hydrae. Both molecules trace a predominantly Keplerian velocity structure, although a slowing of the rotation velocity is detected at the outer edge of the disk beyond ≈140 au in CO emission. This was attributed to the enhanced pressure support from the …
Dynamically Tagged Groups of Metal-poor Stars from the Best and Brightest Survey
Huang, Yang; Casey, Andrew R.; Beers, Timothy C. +9 more
Orbital characteristics based on Gaia Early Data Release 3 astrometric parameters are analyzed for ~4000 metal-poor stars ([Fe/H] ≤ -0.8) compiled from the Best and Brightest survey. Selected as metal-poor candidates based on broadband near- and far-IR photometry, 43% of these stars had medium-resolution (1200 ≲ R ≲ 2000) validation spectra obtain…
Still Brighter than Pre-explosion, SN 2012Z Did Not Disappear: Comparing Hubble Space Telescope Observations a Decade Apart
Foley, Ryan J.; Riess, Adam G.; Kirshner, Robert P. +10 more
Type Iax supernovae (SNe Iax) represent the largest class of peculiar white dwarf supernovae. The type Iax SN 2012Z in NGC 1309 is the only white dwarf supernova with a detected progenitor system in pre-explosion observations. Deep Hubble Space Telescope (HST) images taken before SN 2012Z show a luminous, blue source that we have interpreted as a …