Search Publications
The First Y Dwarf Data from JWST Show that Dynamic and Diabatic Processes Regulate Cold Brown Dwarf Atmospheres
Leggett, S. K.; Tremblin, Pascal
The James Webb Space Telescope (JWST) is now observing Y dwarfs, the coldest known brown dwarfs, with effective temperatures T eff ≲ 475 K. The first published observations provide important information: not only is the atmospheric chemistry out of equilibrium, as previously known, but the pressure-temperature profile is not in the stan…
The First Weak-lensing Analysis with the James Webb Space Telescope: SMACS J0723.3-7327
Faisst, Andreas; Chary, Ranga-Ram; Jee, M. James +1 more
Utilizing the James Webb Space Telescope Early Release NIRCam Observations, we perform a weak-lensing analysis of the massive galaxy cluster SMACS J0723.3-7327 (z = 0.39). We investigate the spatial variation of the point-spread function (PSF) from the stars in the mosaic image. Our measurements show that the PSF for both modules has very small sp…
Enhanced Size Uniformity for Near-resonant Planets
Dai, Fei; Wang, Songhu; Goyal, Armaan V.
Super-Earths within the same close-in, compact planetary system tend to exhibit a striking degree of uniformity in their radius, mass, and orbital spacing, and this "peas-in-a-pod" phenomenon itself serves to provide one of the strongest constrains on planet formation at large. While it has been recently demonstrated from independent samples that …
Effective Temperature Estimations from Line Depth Ratios in the H- and K-band Spectra of IGRINS
Jaffe, Daniel T.; Mace, Gregory N.; Afşar, Melike +5 more
Determining accurate effective temperatures of stars buried in the dust-obscured Galactic regions is extremely difficult from photometry. Fortunately, high-resolution infrared spectroscopy is a powerful tool for determining the temperatures of stars with no dependence on interstellar extinction. It has long been known that the depth ratios of temp…
An APEX Study of Molecular Outflows in FUor-type Stars
Henning, Thomas; Ábrahám, Péter; Kóspál, Ágnes +4 more
The FU Orionis-type objects (FUors) are low-mass pre-main-sequence objects that go through a short-lived phase (~100 yr) of increased mass accretion rate (from 10-8 to 10-4 M ⊙ yr-1). These eruptive young stars are in the early stages of stellar evolution and thus still deeply embedded in a massive envel…
The Spin-Orbit Misalignment of TOI-1842b: The First Measurement of the Rossiter-McLaughlin Effect for a Warm Sub-Saturn around a Massive Star
Rice, Malena; Wang, Songhu; Hixenbaugh, Kyle +1 more
The mechanisms responsible for generating spin-orbit misalignments in exoplanetary systems are still not fully understood. It is unclear whether these misalignments are related to the migration of hot Jupiters or are a consequence of general star and planet formation processes. One promising method to address this question is to constrain the dist…
As Simple as Possible but No Simpler: Optimizing the Performance of Neural Net Emulators for Galaxy SED Fitting
Johnson, Benjamin D.; Tacchella, Sandro; Suess, Katherine A. +7 more
Artificial neural network emulators have been demonstrated to be a very computationally efficient method to rapidly generate galaxy spectral energy distributions, for parameter inference or otherwise. Using a highly flexible and fast mathematical structure, they can learn the nontrivial relationship between input galaxy parameters and output obser…
What Are the Radial Distributions of Density, Outflow Rates, and Cloud Structures in the M82 Wind?
Henry, Alaina; Heckman, Timothy; Xu, Xinfeng +2 more
Galactic winds play essential roles in the evolution of galaxies through the feedback they provide. Despite intensive studies of winds, the radial distributions of their properties and feedback are rarely observable. Here we present such measurements for the prototypical starburst galaxy, M82, based on observations by the Subaru Telescope. We dete…
An Ultradeep Multiband Very Large Array Survey of the Faint Radio Sky (COSMOS-XS): New Constraints on the Optically Dark Population
Smolčić, V.; Walter, F.; Riechers, D. A. +6 more
Attempts to trace star formation with rest-frame UV/optical observations at redshifts z > 2 are affected by the presence of potentially substantial, yet uncertain, dust attenuation. Recent studies have demonstrated the existence of a population of galaxies that are virtually invisible in the observed optical/near-infrared (NIR) due to dust obsc…
Evidence for Misalignment between Debris Disks and Their Host Stars
MacGregor, Meredith A.; Hurt, Spencer A.
We place lower limits on the obliquities between debris disks and their host stars for 31 systems by comparing their disk and stellar inclinations. While previous studies did not find evidence for misalignment, we identify six systems with minimum obliquities falling between ~30°and 60°, indicating that debris disks can be significantly misaligned…