Search Publications
Anomalies in Time Delays of Lensed Gravitational Waves and Dark Matter Substructures
Ding, Xuheng; Biesiada, Marek; Zhu, Zong-Hong +2 more
Cold dark matter scenarios of hierarchical large-scale structure formation predict the existence of abundant subhalos around large galaxies. However, the number of observed dwarf galaxies is far from this theoretical prediction, suggesting that most of the subhalos could be dark or quite faint. Gravitational lensing is a powerful tool to probe the…
Five New Globular Clusters Discovered in the Galactic Bulge
Camargo, Denilso
This Letter reports the discovery of five new globular clusters (GCs) in the Galactic bulge (Camargo 1102, 1103, 1104, 1105, and 1106) using Wide-field Infrared Survey Explorer (WISE) images. Their natures are established by using 2MASS and Gaia second data release (DR2) photometry. The new findings are old and metal-poor GCs located less than 4 k…
Chemical Inhomogeneities in the Pleiades: Signatures of Rocky-forming Material in Stellar Atmospheres
Casey, Andrew R.; Meléndez, Jorge; Spina, Lorenzo +2 more
The aim of Galactic archaeology is to recover the history of our Galaxy through the information encoded in stars. An unprobed assumption of this field is that the chemical composition of a star is an immutable marker of the gas from which it formed. It is vital to test this assumption on open clusters, a group of stars formed from the same gas. Pr…
The Distance to and the Near-infrared Extinction of the Monoceros Supernova Remnant
Jiang, Biwei; Zhao, He; Li, Jun +2 more
Supernova remnants (SNRs) contain information on the influence of supernova explosions on dust properties. Based on the color indices from the Two Micron All Sky Survey and the stellar parameters from the SDSS-DR12/Apache Point Observatory Galactic Evolution Experiment and LAMOST-DR2/LAMOST Experiment for Galactic Understanding and Exploration spe…
Observations of the Kelvin-Helmholtz Instability Driven by Dynamic Motions in a Solar Prominence
Polito, Vanessa; Hillier, Andrew
Prominences are incredibly dynamic across the whole range of their observable spatial scales, with observations revealing gravity-driven fluid instabilities, waves, and turbulence. With all of these complex motions, it would be expected that instabilities driven by shear in the internal fluid motions would develop. However, evidence of these have …
Prediction of Supernova Rates in Known Galaxy-Galaxy Strong-lens Systems
Kang, Xi; Mao, Shude; Bolton, Adam S. +3 more
We propose a new strategy of finding strongly lensed supernovae (SNe) by monitoring known galaxy-scale strong-lens systems. Strongly lensed SNe are potentially powerful tools for the study of cosmology, galaxy evolution, and stellar populations, but they are extremely rare. By targeting known strongly lensed star-forming galaxies, our strategy sig…
Physical Properties of II Zw 40's Super Star Cluster and Nebula: New Insights and Puzzles from UV Spectroscopy
Leitherer, Claus; Lee, Janice C.; Levesque, Emily M. +1 more
We analyze far-ultraviolet spectra and ancillary data of the super star cluster SSC-N and its surrounding H II region in the nearby dwarf galaxy II Zw 40. From the ultraviolet spectrum, we derive a low internal reddening of E(B - V) = 0.07 ± 0.03, a mass of (9.1 ± 1.0) × 105 M ⊙, a bolometric luminosity of (1.1 ± 0.1) × 10
Chemically Dissected Rotation Curves of the Galactic Bulge from Main-sequence Proper Motions
Brown, Thomas M.; Gennaro, Mario; Clarkson, William I. +9 more
We report results from an exploratory study implementing a new probe of Galactic evolution using archival Hubble Space Telescope imaging observations. Precise proper motions are combined with photometric relative metallicity and temperature indices, to produce the proper-motion rotation curves of the Galactic bulge separately for metal-poor and me…
Electron Acceleration and Jet-facilitated Escape in an M-class Solar Flare on 2002 August 19
Fleishman, Gregory D.; Glesener, Lindsay
Sudden jets of collimated plasma arise from many locations on the Sun, including active regions. The magnetic field along which a jet emerges is often open to interplanetary space, offering a clear “escape route” for any flare-accelerated electrons, making jets lucrative targets for studying particle acceleration and the solar sources of transient…
The Formation and Evolution of Galactic Disks with APOGEE and the Gaia Survey
Zhao, Gang; Li, Chengdong; Zhai, Meng +1 more
We explore the structure and evolutionary history of Galactic disks with Apache Point Observatory Galactic Evolution Experiment data release 13 (DR13 hereafter) and Gaia Tycho-Gaia Astrometric Solution data. We use the [α/M] ratio to allocate stars into particular Galactic components to elucidate the chemical and dynamical properties of the thin a…