Search Publications
The Evolution of Rotation and Magnetic Activity in 94 Aqr Aa from Asteroseismology with TESS
Chaplin, William J.; Stassun, Keivan G.; Metcalfe, Travis S. +29 more
Most previous efforts to calibrate how rotation and magnetic activity depend on stellar age and mass have relied on observations of clusters, where isochrones from stellar evolution models are used to determine the properties of the ensemble. Asteroseismology employs similar models to measure the properties of an individual star by matching its no…
Discovery of a Giant Radio Fossil in the Ophiuchus Galaxy Cluster
Wik, D. R.; Giacintucci, S.; Markevitch, M. +3 more
The Ophiuchus galaxy cluster exhibits a curious concave gas density discontinuity at the edge of its cool core. It was discovered in the Chandra X-ray image by Werner and collaborators, who considered the possibility of it being a boundary of an active galactic nucleus (AGN)-inflated bubble located outside the core, but discounted this possibility…
Three-dimensional Kinematic Reconstruction of the Optically Emitting, High-velocity, Oxygen-rich Ejecta of Supernova Remnant N132D
Law, Charles J.; Orlando, Salvatore; Gladders, Michael D. +9 more
We present a three-dimensional kinematic reconstruction of the optically emitting, oxygen-rich ejecta of supernova remnant N132D in the Large Magellanic Cloud (LMC). Data were obtained with the 6.5 m Magellan telescope in combination with the IMACS+GISMO instrument and survey [O III] λλ4959, 5007 line emission in a ∼3' × 3' region centered on N132…
WISE 2150-7520AB: A Very Low-mass, Wide Comoving Brown Dwarf System Discovered through the Citizen Science Project Backyard Worlds: Planet 9
Gonzales, Eileen C.; Meisner, Aaron M.; Burgasser, Adam J. +10 more
We report the discovery of WISE 2150-7520AB (W2150AB): a widely separated (∼341 au) very low-mass L1 + T8 co-moving system. The system consists of the previously known L1 primary 2MASS J21501592-7520367 and a newly discovered T8 secondary found at position 21:50:18.99-75:20:54.6 (MJD = 57947) using Wide-field Infrared Survey Explorer data via the …
The Evolution of the Inner Regions of Protoplanetary Disks
Calvet, Nuria; Lizano, Susana; Miller, Christopher J. +6 more
We present a study of the evolution of the inner few astronomical units of protoplanetary disks around low-mass stars. We consider nearby stellar groups with ages spanning from 1 to 11 Myr, distributed into four age bins. Combining PANSTARSS photometry with spectral types, we derive the reddening consistently for each star, which we use (1) to mea…
Solar Flare Arcade Modeling: Bridging the Gap from 1D to 3D Simulations of Optically Thin Radiation
Polito, Vanessa; Kerr, Graham S.; Allred, Joel C.
Solar flares are 3D phenomena, but modeling a flare in 3D, including many of the important processes in the chromosphere, is a computational challenge. Accurately modeling the chromosphere is important, even if the transition region and corona are the areas of interest, due to the flow of energy, mass, and radiation through the interconnected laye…
A Word to the WISE: Confusion is Unavoidable for WISE-selected Infrared Excesses
Debes, John H.; Gentile Fusillo, Nicola Pietro; Farihi, Jay +1 more
Stars with excess infrared radiation from circumstellar dust are invaluable for studies of exoplanetary systems, informing our understanding of processes of planet formation and destruction alike. All-sky photometric surveys have made the identification of dusty infrared excess candidates trivial, however, samples that rely on data from Wise Infra…
Discovery of a Large Population of Nitrogen-enhanced Stars in the Magellanic Clouds
Beers, Timothy C.; Placco, Vinicius M.; Minniti, Dante +7 more
We report the APOGEE-2S+ discovery of a unique collection of nitrogen-enhanced mildly metal-poor giant stars, peaking at [Fe/H] ∼ -0.89 with no carbon enrichment, toward the Small and Large Magellanic Clouds (SMC and LMC), with abundances of light- (C, N), odd-Z (Al, K), and α-elements (O, Mg, Si) that are typically found in Galactic globular clus…
Fast Outflows in Hot Dust-obscured Galaxies Detected with Keck/NIRES
Tsai, Chao-Wei; Moon, Dae-Sik; Jun, Hyunsung D. +10 more
We present rest-frame optical spectroscopic observations of 24 Hot Dust-Obscured Galaxies (Hot DOGs) at redshifts 1.7-4.6 with KECK/NIRES. Our targets are selected, based on their extreme red colors, to be the highest-luminosity sources from the WISE infrared survey. In 20 sources with well-detected emission, we fit the key [O III], Hβ, Hα, [N II]…
Real-time Flare Prediction Based on Distinctions between Flaring and Non-flaring Active Region Spectra
Kleint, Lucia; Panos, Brandon
With machine learning entering into the awareness of the heliophysics community, solar flare prediction has become a topic of increased interest. Although machine-learning models have advanced with each successive publication, the input data has remained largely fixed on magnetic features. Despite this increased model complexity, results seem to i…