Search Publications
The Ice Chemistry in Comets and Planet-forming Disks: Statistical Comparison of CH3OH, H2CO, and NH3 Abundance Ratios
Ceccarelli, Cecilia; Codella, Claudio; Villanueva, Geronimo L. +5 more
Comets are frozen remnants of our solar system's formation, and comparing their chemical composition to that of planet-forming systems can reveal crucial insights about our origins, potentially answering one of the most challenging questions in planetary science, i.e., whether cometary material was mainly inherited from the protosolar nebula or re…
GRB 240529A: A Tale of Two Shocks
Fang, Min; Liu, Hao; Liu, Wei +66 more
Thanks to the rapidly increasing time-domain facilities, we are entering a golden era of research on gamma-ray bursts (GRBs). In this Letter, we report our observations of GRB 240529A with the Burst Optical Observer and Transient Exploring System, the 1.5 m telescope at Observatorio de Sierra Nevada, the 2.5 m Wide Field Survey Telescope of China,…
New Insights into the Internal Structure of GJ 1214 b Informed by JWST
Eastman, Jason D.; Bean, Jacob L.; Zhang, Michael +7 more
Recent JWST observations of the sub-Neptune GJ 1214 b suggest that it hosts a high-metallicity (≳100× solar), hazy atmosphere. Emission spectra of the planet show molecular absorption features, most likely due to atmospheric H2O. In light of this new information, we conduct a thorough reevaluation of the planet's internal structure. We …
Stellar Evolution in Real Time. II. R Hydrae and an Open-Source Grid of >3000 Seismic TP-AGB Models Computed with MESA
Tayar, Jamie; Joyce, Meridith; Molnár, László +3 more
We present a comprehensive characterization of the evolved thermally pulsing asymptotic giant branch (TP-AGB) star R Hydrae (R Hya), building on the techniques applied in Stellar Evolution in Real Time I (Molnár et al.) to T Ursae Minoris. We compute over 3000 theoretical TP-AGB pulse spectra using MESA and the corresponding oscillation spectra wi…
Methods for Incorporating Model Uncertainty into Exoplanet Atmospheric Analysis
McGill, Peter; Kempton, Eliza M. -R.; Nixon, Matthew C. +1 more
A key goal of exoplanet spectroscopy is to measure atmospheric properties, such as abundances of chemical species, in order to connect them to our understanding of atmospheric physics and planet formation. In this new era of high-quality JWST data, it is paramount that these measurement methods are robust. When comparing atmospheric models to obse…
Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-mass Star-forming Region NGC 2264: Global Properties and Local Magnetogravitational Configurations
Zhang, Yapeng; Pattle, Kate; Karoly, Janik +154 more
We report 850 µm continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of the B-fields In STar forming Regions Observations large program on the James Clerk Maxwell Telescope. These data reveal a well-structured nonuniform magnetic field in the NGC 2264C and 2264D regions with a prev…
Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. VIII. Mapping the Kinematics of the Galactic Disk Using Mono-age and Mono-abundance Stellar Populations
Huang, Yang; Jiang, Biwei; Zhang, Huawei +5 more
We present a comprehensive study of the kinematic properties of the different Galactic disk populations, as defined by the chemical abundance ratios and stellar ages, across a large disk volume (4.5 ≤ R ≤ 15.0 kpc and ∣Z∣ ≤ 3.0 kpc), by using the LAMOST-Gaia red clump sample stars. We determine the median velocities for various spatial and populat…
J-PLUS: Beyond Spectroscopy. III. Stellar Parameters and Elemental-abundance Ratios for Five Million Stars from DR3
Fan, Zhou; Huang, Yang; Liu, Jifeng +24 more
We present a catalog of stellar parameters (effective temperature T eff, surface gravity
Reading between the (Spectral) Lines: Magellan/IMACS Spectroscopy of the Ultrafaint Dwarf Galaxies Eridanus IV and Centaurus I
James, D. J.; Li, T. S.; Carlin, J. L. +18 more
We present a spectroscopic analysis of Eridanus IV (Eri IV) and Centaurus I (Cen I), two ultrafaint dwarf galaxies of the Milky Way. Using IMACS/Magellan spectroscopy, we identify 28 member stars of Eri IV and 34 member stars of Cen I. For Eri IV, we measure a systemic velocity of ${v}_{\mathrm{sys}}=-{31.5}_{-1.2}^{+1.3}\ \mathrm{km}\,{{\rm{s}}}^…
What is the Reynolds Number of the Solar Wind?
Wrench, Daniel; Parashar, Tulasi N.; Oughton, Sean +2 more
The Reynolds number, Re, is an important quantity for describing a turbulent flow. It tells us about the bandwidth over which energy can cascade from large scales to smaller ones, prior to the onset of dissipation. However, calculating it for nearly collisionless plasmas like the solar wind is challenging. Previous studies have used formulations o…