Search Publications
The Evolution of Solar Flux from 0.1 nm to 160 µm: Quantitative Estimates for Planetary Studies
Meadows, Victoria S.; Cohen, Martin; Catling, David C. +3 more
Understanding changes in the solar flux over geologic time is vital for understanding the evolution of planetary atmospheres because it affects atmospheric escape and chemistry, as well as climate. We describe a numerical parameterization for wavelength-dependent changes to the non-attenuated solar flux appropriate for most times and places in the…
Sizes and Surface Brightness Profiles of Quiescent Galaxies at z ~ 2
van Dokkum, Pieter G.; Franx, Marijn; Szomoru, Daniel
We use deep Hubble Space Telescope Wide Field Camera 3 near-infrared imaging obtained of the GOODS-South field as part of the CANDELS survey to investigate a stellar mass-limited sample of quiescent galaxies at 1.5 < z < 2.5. We measure surface brightness profiles for these galaxies using a method that properly measures low surface brightnes…
Dissipationless Formation and Evolution of the Milky Way Nuclear Star Cluster
Mastrobuono-Battisti, Alessandra; Merritt, David; Antonini, Fabio +1 more
In one widely discussed model for the formation of nuclear star clusters (NSCs), massive globular clusters spiral into the center of a galaxy and merge to form the nucleus. It is now known that at least some NSCs coexist with supermassive black holes (SMBHs); this is the case, for instance, in the Milky Way. In this paper, we investigate how the p…
The 4 Ms Chandra Deep Field-South Number Counts Apportioned by Source Class: Pervasive Active Galactic Nuclei and the Ascent of Normal Galaxies
Lehmer, B. D.; Hornschemeier, A. E.; Ptak, A. +13 more
We present 0.5-2 keV, 2-8 keV, 4-8 keV, and 0.5-8 keV (hereafter soft, hard, ultra-hard, and full bands, respectively) cumulative and differential number-count (log N-log S) measurements for the recently completed ≈4 Ms Chandra Deep Field-South (CDF-S) survey, the deepest X-ray survey to date. We implement a new Bayesian approach, which allows rel…
GOODS-Herschel and CANDELS: The Morphologies of Ultraluminous Infrared Galaxies at z ~ 2
Bell, Eric F.; Dickinson, Mark; Ferguson, Henry C. +40 more
Using deep 100 and 160 µm observations in GOODS-South from GOODS-Herschel, combined with high-resolution HST/WFC3 near-infrared imaging from CANDELS, we present the first detailed morphological analysis of a complete, far-infrared (FIR) selected sample of 52 ultraluminous infrared galaxies (ULIRGs; L IR > 1012 L
A Cool Dust Factory in the Crab Nebula: A Herschel Study of the Filaments
Ivison, R. J.; Henning, Th.; Krause, O. +13 more
Whether supernovae are major sources of dust in galaxies is a long-standing debate. We present infrared and submillimeter photometry and spectroscopy from the Herschel Space Observatory of the Crab Nebula between 51 and 670 µm as part of the Mass Loss from Evolved StarS program. We compare the emission detected with Herschel with multiwavele…
Composition of the Solar Corona, Solar Wind, and Solar Energetic Particles
Schmelz, J. T.; Reames, D. V.; von Steiger, R. +1 more
Along with temperature and density, the elemental abundance is a basic parameter required by astronomers to understand and model any physical system. The abundances of the solar corona are known to differ from those of the solar photosphere via a mechanism related to the first ionization potential of the element, but the normalization of these val…
Strong Tidal Dissipation in Saturn and Constraints on Enceladus' Thermal State from Astrometry
Charnoz, Sébastien; Mathis, Stéphane; Tobie, Gabriel +8 more
Tidal interactions between Saturn and its satellites play a crucial role in both the orbital migration of the satellites and the heating of their interiors. Therefore, constraining the tidal dissipation of Saturn (here the ratio k 2/Q) opens the door to the past evolution of the whole system. If Saturn's tidal ratio can be determined at…
EVLA Observations Constrain the Environment and Progenitor System of Type Ia Supernova 2011fe
Fransson, Claes; Chevalier, Roger A.; Chomiuk, Laura +7 more
We report unique Expanded Very Large Array observations of SN 2011fe representing the most sensitive radio study of a Type Ia supernova to date. Our data place direct constraints on the density of the surrounding medium at radii ~1015-1016 cm, implying an upper limit on the mass loss rate from the progenitor system of \dot{M}…
Near-ultraviolet Absorption, Chromospheric Activity, and Star-Planet Interactions in the WASP-12 system
Burwitz, V.; France, K.; Fossati, L. +15 more
Extended gas clouds have been previously detected surrounding the brightest known close-in transiting hot Jupiter exoplanets, HD 209458 b and HD 189733 b we observed the distant but more extreme close-in hot Jupiter system, WASP-12, with Hubble Space Telescope (HST). Near-UV (NUV) transits up to three times deeper than the optical transit of WASP-…