Search Publications
Accretion-driven Sources in Spatially Resolved Lyα Emitters
Hayes, Matthew; Östlin, Göran; Melinder, Jens +4 more
Lyα emission is a standard tracer of starburst galaxies at high redshift. However, a number of local Lyα emitters (LAEs) are X-ray sources, suggesting a possible origin of Lyα photons other than young, hot stars, and which may be active at much later ages relative to the parent starburst. Resolved, nearby LAEs offer the opportunity to discriminate…
Direct Imaging Discovery of a Young Brown Dwarf Companion to an A2V Star
Currie, Thayne; Wagner, Kevin; Apai, Dániel +3 more
We present the discovery and spectroscopy of HIP 75056Ab, a companion directly imaged at a very small separation of 0"125 to an A2V star in the Scorpius-Centaurus OB2 association. Our observations utilized Very Large Telescope/Spectro-Polarimetric High-contrast Exoplanet Research Experiment between 2015 and 2019, enabling low-resolution spectrosco…
Three Dusty Star-forming Galaxies at z ∼ 1.5: Mergers and Disks on the Main Sequence
Casey, Caitlin M.; Whitaker, Katherine E.; Cooray, Asantha +1 more
The main sequence of galaxies, a correlation between the star formation rates (SFRs) and stellar masses of galaxies, has been observed out to z ∼ 4. Galaxies within the scatter of the correlation are typically interpreted to be secularly evolving while galaxies with SFRs elevated above the main sequence are interpreted to be undergoing interaction…
Deviations from the Infrared-radio Correlation in Massive, Ultracompact Starburst Galaxies
Moustakas, John; Coil, Alison L.; Rudnick, Gregory H. +11 more
Feedback through energetic outflows has emerged as a key physical process responsible for transforming star-forming galaxies into the quiescent systems observed in the local universe. To explore this process, this paper focuses on a sample of massive and compact merger remnant galaxies hosting high-velocity gaseous outflows ( $| v| \gtrsim {10}^{3…
ROBO-AO Kepler Asteroseismic Survey. II. Do Stellar Companions Inhibit Stellar Oscillations?
Kulkarni, S. R.; Baranec, Christoph; Duev, Dmitry A. +7 more
The Kepler Space Telescope observed over 15,000 stars for asteroseismic studies. Of these, 75% of dwarfs (and 8% of giants) were found to show anomalous behavior, such as suppressed oscillations (low amplitude) or no oscillations at all. The lack of solar-like oscillations may be a consequence of multiplicity, due to physical interactions with spe…
Clustering of Fast Coronal Mass Ejections during Solar Cycles 23 and 24 and the Implications for CME-CME Interactions
Veronig, Astrid; Podladchikova, Tatiana; Feynman, Joan +3 more
We study the clustering properties of fast coronal mass ejections (CMEs) that occurred during solar cycles 23 and 24. We apply two methods: the Max Spectrum method can detect the predominant clusters, and the declustering threshold time method provides details on the typical clustering properties and timescales. Our analysis shows that during the …
Whether Small Flux Ropes and Magnetic Clouds Have the Same Origin: A Statistical Study of Small Flux Ropes in Different Types of Solar Wind
Wang, Yuming; Shen, Chenglong; Hu, Qiang +2 more
According to the duration and size, magnetic flux ropes can be divided into large-scale flux ropes, namely, magnetic clouds, and small-scale flux ropes (SFRs). Whether SFRs have the same origin as magnetic clouds has been a hot topic for a long time. Based on the SFR database developed by Hu et al. and Chen et al., this paper analyzes the properti…
The TRENDS High-contrast Imaging Survey. VIII. Compendium of Benchmark Objects
Howard, Andrew W.; Crepp, Justin R.; Montet, Benjamin T. +5 more
The physical properties of faint stellar and substellar objects often rely on indirect, model-dependent estimates. For example, the masses of brown dwarfs are usually inferred using evolutionary models, which are age dependent and have yet to be properly calibrated. With the goal of identifying new benchmark objects to test low-mass stellar and su…
Spatially Resolved UV Diagnostics of AGN Feedback: Radiation Pressure Dominates in a Prototypical Quasar-driven Superwind
Stern, Jonathan; Johnson, Sean D.; Chen, Hsiao-Wen +5 more
Galactic-scale winds driven by active galactic nuclei (AGN) are often invoked to suppress star formation in galaxy evolution models, but the mechanisms driving these outflows are hotly debated. Two key AGN feedback models are (1) radiation pressure accelerating cool gas and (2) a hot outflowing wind entraining the interstellar medium (ISM). Highly…
Modeling Photoionized Turbulent Material in the Circumgalactic Medium. II. Effect of Turbulence within a Stratified Medium
Safarzadeh, Mohammadtaher; Buie, Edward, II; Gray, William J. +1 more
The circumgalactic medium (CGM) of nearby star-forming galaxies shows clear indications of O VI absorption accompanied by little to no detectable N V absorption. This unusual spectral signature, accompanied by highly nonuniform absorption from lower-ionization-state species, indicates that the CGM must be viewed as a dynamic, multiphase medium, su…