Search Publications
Spectral Properties of Cool Stars: Extended Abundance Analysis of Kepler Objects of Interest
Fischer, Debra A.; Brewer, John M.
Accurate stellar parameters and precise elemental abundances are vital pieces to correctly characterize discovered planetary systems, better understand planet formation, and trace galactic chemical evolution. We have performed a uniform spectroscopic analysis for 1127 stars, yielding accurate gravity, temperature, and projected rotational velocity…
Planck Sunyaev-Zel'dovich cluster mass calibration using Hyper Suprime-Cam weak lensing
Sifón, Cristóbal; Battaglia, Nicholas; Miyatake, Hironao +9 more
Using ∼140 deg2 Subaru Hyper Suprime-Cam (HSC) survey data, we stack the weak lensing (WL) signal around five Planck clusters found within the footprint. This yields a 15σ detection of the mean Planck cluster mass density profile. The five Planck clusters span a relatively wide mass range, MWL,500c = (2-30) × 1014 …
Krypton isotopes and noble gas abundances in the coma of comet 67P/Churyumov-Gerasimenko
Mall, Urs; Bar-Nun, Akiva; De Keyser, Johan +24 more
The ROSINA mass spectrometer DFMS on board ESA's Rosetta spacecraft detected the major isotopes of the noble gases argon, krypton, and xenon in the coma of comet 67P/Churyumov-Gerasimenko. Earlier, it has been shown that xenon exhibits an isotopic composition distinct from anywhere else in the solar system. However, argon isotopes, within error, w…
Global Non-Potential Magnetic Models of the Solar Corona During the March 2015 Eclipse
Morgan, Huw; Feng, Xueshang; Downs, Cooper +17 more
Seven different models are applied to the same problem of simulating the Sun's coronal magnetic field during the solar eclipse on 2015 March 20. All of the models are non-potential, allowing for free magnetic energy, but the associated electric currents are developed in significantly different ways. This is not a direct comparison of the coronal m…
Mean winds at the cloud top of Venus obtained from two-wavelength UV imaging by Akatsuki
Imamura, Takeshi; Takagi, Masahiro; Yamazaki, Atsushi +9 more
Venus is covered with thick clouds. Ultraviolet (UV) images at 0.3–0.4 microns show detailed cloud features at the cloud-top level at about 70 km, which are created by an unknown UV-absorbing substance. Images acquired in this wavelength range have traditionally been used to measure winds at the cloud top. In this study, we report low-latitude win…
Abundances, Ionization States, Temperatures, and FIP in Solar Energetic Particles
Reames, Donald V.
The relative abundances of chemical elements and isotopes have been our most effective tool in identifying and understanding the physical processes that control populations of energetic particles. The early surprise in solar energetic particles (SEPs) was 1000-fold enhancements in {}3He/{}4He from resonant wave-particle inter…
The Local Bubble: a magnetic veil to our Galaxy
Boulanger, F.; Alves, M. I. R.; Montier, L. +1 more
The magnetic field in the local interstellar medium does not follow the large-scale Galactic magnetic field. The local magnetic field has probably been distorted by the Local Bubble, a cavity of hot ionized gas extending all around the Sun and surrounded by a shell of cold neutral gas and dust. However, so far no conclusive association between the…
HelMod in the Works: From Direct Observations to the Local Interstellar Spectrum of Cosmic-Ray Electrons
Jóhannesson, G.; Moskalenko, I. V.; Porter, T. A. +11 more
The local interstellar spectrum (LIS) of cosmic-ray (CR) electrons for the energy range 1 MeV to 1 TeV is derived using the most recent experimental results combined with the state-of-the-art models for CR propagation in the Galaxy and in the heliosphere. Two propagation packages, GALPROP and HELMOD, are combined to provide a single framework that…
The California-Kepler Survey. VI. Kepler Multis and Singles Have Similar Planet and Stellar Properties Indicating a Common Origin
Fulton, Benjamin J.; Isaacson, Howard T.; Howard, Andrew W. +8 more
The California-Kepler Survey (CKS) catalog contains precise stellar and planetary properties for the Kepler planet candidates, including systems with multiple detected transiting planets (“multis”) and systems with just one detected transiting planet (“singles”, although additional planets could exist). We compared the stellar and planetary proper…
MAGIICAT VI. The Mg II Intragroup Medium Is Kinematically Complex
Kacprzak, Glenn G.; Churchill, Christopher W.; Nielsen, Nikole M. +2 more
By comparing Mg II absorption in the circumgalactic medium (CGM) of group environments to isolated galaxies, we investigated the impact of environment on the CGM. An Mg II absorber is associated with a group if there are two or more galaxies at the absorption redshift within a projected distance of D = 200 kpc from a background quasar and a line-o…