Search Publications
Modeling the 2012 May 17 Solar Energetic Particle Event Using the AWSoM and iPATH Models
Lario, D.; Li, Gang; de Nolfo, G. A. +6 more
We model the 2012 May 17 solar energetic particle event by combining the AWSoM and iPATH codes. Using this combined approach, we investigate particle acceleration when the parent coronal mass ejection (CME) is still close to the Sun. We have obtained reasonable agreements between our simulation and observations made by multiple spacecraft. We foll…
Source Counts Spanning Eight Decades of Flux Density at 1.4 GHz
Mauch, T.; Condon, J. J.; Cotton, W. D. +1 more
Brightness-weighted differential source counts S2n(S) spanning the eight decades of flux density between 0.25 µJy and 25 Jy at 1.4 GHz were measured from (1) the confusion brightness distribution in the MeerKAT DEEP2 image below 10 µJy, (2) counts of DEEP2 sources between 10 µJy and 2.5 mJy, and (3) counts of NVSS sour…
Thermal and Turbulent Properties of the Warm Neutral Medium in the Solar Neighborhood
Miville-Deschênes, Marc-Antoine; Marchal, Antoine
The transition from the diffuse warm neutral medium (WNM) to the dense cold neutral medium (CNM) is what set the initial conditions to the formation of molecular clouds. The properties of the turbulent cascade in the WNM, essential to describe this radiative condensation process, have remained elusive in part due to the difficulty in mapping out t…
Cepheids with Giant Companions. I. Revealing a Numerous Population of Double-lined Binary Cepheids
Anderson, Richard I.; Gieren, Wolfgang; Pietrzyński, Grzegorz +5 more
Masses of classical Cepheids of 3-11 M⊙ are predicted by theory but those measured clump between 3.6-5 M⊙. As a result, their mass-luminosity relation is poorly constrained, impeding our understanding of basic stellar physics and the Leavitt Law. All Cepheid masses come from the analysis of 11 binary systems, including only f…
The Carnegie Chicago Hubble Program X: Tip of the Red Giant Branch Distances to NGC 5643 and NGC 1404
Madore, Barry F.; Freedman, Wendy L.; Beaton, Rachael L. +7 more
The primary goal of the Carnegie Chicago Hubble Program (CCHP) is to calibrate the zero-point of the Type Ia supernova (SN Ia) Hubble Diagram through the use of Population II standard candles. So far, the CCHP has measured direct distances to 11 SNe Ia, and here we increase that number to 15 with two new Tip of the Red Giant Branch (TRGB) distance…
Investigating the Relative Gas and Small Dust Grain Surface Heights in Protoplanetary Disks
Monnier, John D.; Adams, Fred C.; Teague, Richard +7 more
Dust evolution in protoplanetary disks from small dust grains to pebbles is key to the planet formation process. The gas in protoplanetary disks should influence the vertical distribution of small dust grains (∼1 µm) in the disk. Utilizing archival near-infrared polarized light and millimeter observations, we can measure the scale height and…
Threads, Ribbons, and Rings in the Radio Galaxy IC 4296
Camilo, F.; White, S. V.; Condon, J. J. +5 more
The nearby elliptical galaxy IC 4296 has produced a large (510 kpc) low-luminosity radio source with typical FR I core/jet/lobe morphology. The unprecedented combination of brightness sensitivity, dynamic range, and angular resolution of a new 1.28 GHz MeerKAT continuum image reveals striking new morphological features, which we call threads, ribb…
Radial Migration from the Metallicity Gradient of Open Clusters and Outliers
Zhao, Gang; Chen, Yuqin; Zhang, Haopeng
Radial migration is an important process in the evolution of the Galactic disk. The metallicity gradient of open clusters and its outliers provide an effective way to examine this process. In this work, we compile metallicity, age, and kinematic parameters for 225 open clusters and carry out a quantitative analysis of radial migration via the calc…
An Exploration of Model Degeneracies with a Unified Phase Curve Retrieval Analysis: The Light and Dark Sides of WASP-43 b
Waldmann, I. P.; Tinetti, G.; Edwards, B. +2 more
The analysis of exoplanetary atmospheres often relies upon the observation of transit or eclipse events. While very powerful, these snapshots provide mainly one-dimensional information on the planet structure and do not easily allow precise latitude-longitude characterizations. The phase curve technique, which consists of measuring the planet emis…
Uniform Forward-modeling Analysis of Ultracool Dwarfs. II. Atmospheric Properties of 55 Late-T Dwarfs
Line, Michael R.; Marley, Mark S.; Liu, Michael C. +2 more
We present a large uniform forward-modeling analysis for 55 late-T (T7-T9) dwarfs, using low-resolution (R ≈ 50-250) near-infrared (1.0-2.5 µm) spectra and cloudless Sonora-Bobcat model atmospheres. We derive the objects' effective temperatures, surface gravities, metallicities, radii, masses, and bolometric luminosities using our newly deve…