Search Publications
JWST MIRI MRS Observations of T Cha: Discovery of a Spatially Resolved Disk Wind
Pascucci, Ilaria; Gorti, Uma; Xie, Chengyan +8 more
Understanding when and how circumstellar disks disperse is crucial to constrain planet formation and migration. Thermal winds powered by high-energy stellar photons have long been theorized to drive disk dispersal. However, evidence for these winds is currently based only on small (∼3–6 km s‑1) blueshifts in [Ne II] 12.81 µm lines…
Deep Hubble Space Telescope Photometry of Large Magellanic Cloud and Milky Way Ultrafaint Dwarfs: A Careful Look into the Magnitude–Size Relation
Choi, Yumi; van der Marel, Roeland P.; Torrey, Paul +16 more
We present deep Hubble Space Telescope photometry of 10 targets from Treasury Program GO-14734, including six confirmed ultrafaint dwarf (UFD) galaxies, three UFD candidates, and one likely globular cluster. Six of these targets are satellites of, or have interacted with, the Large Magellanic Cloud (LMC). We determine their structural parameters u…
The Size–Mass Relation at Rest-frame 1.5 µm from JWST/NIRCam in the COSMOS-WEB and PRIMER-COSMOS Fields
Bell, Eric F.; Franx, Marijn; van der Wel, Arjen +4 more
We present the galaxy stellar mass–size relation in the rest-frame near-IR (1.5 µm) and its evolution with redshift up to z = 2.5. Sérsic profiles are measured for ∼26,000 galaxies with stellar masses M ⋆ > 109 M ⊙ from JWST/NIRCam F277W and F444W imaging provided by the COSMOS-WEB and PRIMER surveys using…
TESS Cycle 2 observations of roAp stars with 2-min cadence data
Handler, G.; Derekas, A.; Niemczura, E. +47 more
We present the results of a systematic search of the Transiting Exoplanet Survey Satellite (TESS) 2-min cadence data for new rapidly oscillating Ap (roAp) stars observed during the Cycle 2 phase of its mission. We find seven new roAp stars previously unreported as such and present the analysis of a further 25 roAp stars that are already known. Thr…
Physical properties of extreme emission-line galaxies at z ∼ 4–9 from the JWST CEERS survey
Kartaltepe, J. S.; Dickinson, M.; Finkelstein, S. L. +22 more
Context. Extreme emission line galaxies (EELGs) are typically characterized by high equivalent widths (EWs) which are driven by elevated specific star formation rates (sSFRs) in low-mass galaxies with subsolar metallicities and little dust. Such extreme systems are exceedingly rare in the local universe, but the number density of EELGs increases w…
Science with a Small Two-Band UV-Photometry Mission I: Mission Description and Follow-up Observations of Stellar Transients
Behar, E.; Chang, Hsiang-Kuang; Merc, J. +33 more
This is the first in a collection of three papers introducing the science with an ultra-violet (UV) space telescope on an approximately 130 kg small satellite with a moderately fast re-pointing capability and a real-time alert communication system approved for a Czech national space mission. The mission, called Quick Ultra-Violet Kilonova surveyor…
Could very low-metallicity stars with rotation-dominated orbits have been driven by the bar?
Li, Chengdong; Sestito, Federico; Ibata, Rodrigo A. +12 more
The most metal-poor stars (e.g., [Fe/H] ≤ –2.5) are the ancient fossils from the early assembly epoch of our Galaxy. They very likely formed before the the thick disk. Recent studies have shown that a non-negligible fraction of them have prograde planar orbits, which means that their origin is a puzzle. It has been suggested that a later-formed ro…
Spectroscopic Distance, Mass, and Age Estimations for APOGEE DR17
Brownstein, Joel R.; Stassun, Keivan G.; Holtzman, Jon A. +3 more
We derive distances and masses of stars from the Sloan Digital Sky Survey (SDSS) Apache Point Observatory Galactic Evolution Experiment Data Release 17 using simple neural networks. Training data for distances comes from Gaia EDR3, supplemented by literature distances for star clusters. For masses, the network is trained using asteroseismic masses…
GHOST commissioning science results - II: a very metal-poor star witnessing the early galactic assembly
Hayes, Christian R.; Sestito, Federico; Jensen, Jaclyn +25 more
This study focuses on Pristine$\_180956.78$-294759.8 (hereafter P180956, [Fe/H] = -1.95 ± 0.02), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up with the recently commissioned Gemini High-resolution Optical SpecTrograph (GHOST) at the Gemini South telescope. The GHOST spectrograph's high efficiency in the blue spectra…
Probing the physics of star formation (ProPStar). I. First resolved maps of the electron fraction and cosmic-ray ionization rate in NGC 1333
Caselli, Paola; Chen, Mike; Neri, Roberto +11 more
Context. Electron fraction and cosmic-ray ionization rates in star-forming regions are important quantities in astrochemical modeling and are critical to the degree of coupling between neutrals, ions, and electrons, which regulates the dynamics of the magnetic field. However, these are difficult quantities to estimate.
Aims: We aim to derive …