Search Publications
Ages of "Singles" versus "Multis": Predictions for Dynamical Sculpting over Gyr in the Kepler Sample
Ballard, Sarah; Lam, Christopher
The sample of host stars with multiple transiting planets has illuminated the orbital architectures of exoplanetary systems. These architectures may be shaped mostly by formation conditions, be continually sculpted by ongoing dynamical processes, or both. As more studies have placed planet occurrence within a galactic context, evidence has emerged…
An Imaging and Spectroscopic Exploration of the Dusty Compact Obscured Nucleus Galaxy Zw 049.057
Gallagher, J. S.; Evans, A.; Privon, G. C. +9 more
Zw 049.057 is a moderate-mass, dusty, early-type galaxy that hosts a powerful compact obscured nucleus (CON, L FIR,CON ≥ 1011 L ⊙). The resolution of the Hubble Space Telescope enabled measurements of the stellar light distribution and characterization of dust features. Zw 049.057 is inclined with a prominent three…
Fermi-bubble Bulk and Edge Analysis Reveals Dust, Cooling Breaks, and Cosmic-Ray Diffusion, Facilitating a Self-consistent Model
Keshet, Uri; Gurwich, Ilya; Lavi, Assaf +2 more
The full, radio to γ-ray spectrum of the Fermi bubbles is shown to be consistent with standard strong-shock electron acceleration at the bubble edge, without the unnatural energy cutoffs and unrealistic electron cooling of previous studies, if the ambient interstellar radiation is strong; the γ-ray cooling break should then have a microwave counte…
Hunting for Hydrated Minerals on Trans-Neptunian Objects
Fraser, Wesley C.; Puzia, Thomas H.; Seccull, Tom +1 more
We present new optical reflectance spectra of three potentially silicate-rich trans-Neptunian objects (TNOs). These spectra were obtained with the aim of confirming past hints and detections of λ ∼ 0.7 µm absorption features associated with the presence of iron-bearing phyllosilicates. Our new spectrum of 120216 (2004 EW95) presen…
The Cluster Spacecrafts' View Of The Motion Of The High-Latitude Magnetopause
Darrouzet, Fabien; Plaschke, Ferdinand; Grimmich, Niklas +10 more
The magnetopause is the boundary between the interplanetary magnetic field and the terrestrial magnetic field. It is influenced by different solar-wind conditions, which lead to a change in the shape and location of the magnetopause. The interaction between the solar wind and the magnetosphere can be studied from in situ spacecraft observations. M…
Determining the Origin of Very-high-energy Gamma Rays from Galactic Sources by Future Neutrino Observations
Wang, Kai; Song, Bo-Heng; Huang, Tian-Qi
Recently, the Large High Altitude Air Shower Observatory (LHAASO) identified 12 gamma-ray sources emitting gamma rays with energies above 100 TeV, making them potential PeV cosmic-ray accelerators (PeVatrons). Neutrino observations are crucial in determining whether the gamma-ray radiation process is of hadronic or leptonic origin. In this paper, …
Benchmarking the spectroscopic masses of 249 evolved stars using asteroseismology with TESS
Huber, Daniel; Bedding, Timothy R.; Stello, Dennis +5 more
One way to understand planet formation is through studying the correlations between planet occurrence rates and stellar mass. However, measuring stellar mass in the red giant regime is very difficult. In particular, the spectroscopic masses of certain evolved stars, often referred to as 'retired A-stars', have been questioned in the literature. Ef…
Detection of the Temperature Dependence of the White Dwarf Mass–Radius Relation with Gravitational Redshifts
Hermes, J. J.; Zakamska, Nadia L.; Gänsicke, Boris T. +8 more
Models predict that the well-studied mass–radius relation of white dwarf stars depends on the temperature of the star, with hotter white dwarfs having larger masses at a given radius than cooler stars. In this paper, we use a catalog of 26,041 DA white dwarfs observed in Sloan Digital Sky Survey Data Releases 1–19. We measure the radial velocity, …
Light curves for 10 R Coronae Borealis stars for longer than a century: secular evolution, dip statistics, and a general model for the shape of isolated light-curve dips
Schaefer, Bradley E.
R Coronae Borealis stars (RCBs) are cool supergiants that display non-periodic deep dips in brightness. Recently, a group of 'Hot RCB stars' has been discovered to be fast evolving across the HR (Hertzsprung-Russell) diagram, as these stars leave the RCB region, with brightness changes at the rate of ~1 mag per century. Perhaps cool RCB stars can …
Orbits and dynamical masses for the active Hyades multiple system HD 284163
Torres, Guillermo; Latham, David W.; Monnier, John D. +16 more
We report near-infrared long-baseline interferometric observations of the Hyades multiple system HD 284163, made with the Center for High Angular Resolution Astronomy array, as well as almost 43 yr of high-resolution spectroscopic monitoring at the Center for Astrophysics. Both types of observations resolve the 2.39 d inner binary, and also an out…