Search Publications
A Unified Empirical Model for Infrared Galaxy Counts Based on the Observed Physical Evolution of Distant Galaxies
Buat, Véronique; Daddi, Emanuele; Hezaveh, Yashar +10 more
We reproduce the mid-infrared to radio galaxy counts with a new empirical model based on our current understanding of the evolution of main-sequence (MS) and starburst (SB) galaxies. We rely on a simple spectral energy distribution (SED) library based on Herschel observations: a single SED for the MS and another one for SB, getting warmer with red…
CANDELS: The Contribution of the Observed Galaxy Population to Cosmic Reionization
Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +12 more
We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6 <~ z <~ 8. These galaxies were selected from new deep near-infrared Hubble Space Telescope imaging from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble UltraDeep Field 2009, and Wide Field Camera 3 Early Releas…
Modeling the Effects of Star Formation Histories on Hα and Ultraviolet Fluxes in nearby Dwarf Galaxies
Skillman, Evan D.; Williams, Benjamin F.; Johnson, L. Clifton +9 more
We consider the effects of non-constant star formation histories (SFHs) on Hα and GALEX far-ultraviolet (FUV) star formation rate (SFR) indicators. Under the assumption of a fully populated Chabrier initial mass function (IMF), we compare the distribution of Hα-to-FUV flux ratios from ~1500 simple, periodic model SFHs with observations of 185 gala…
Resolving the Electron Temperature Discrepancies in H II Regions and Planetary Nebulae: κ-distributed Electrons
Dopita, Michael A.; Nicholls, David C.; Sutherland, Ralph S.
The measurement of electron temperatures and metallicities in H II regions and planetary nebulae (PNe) has—for several decades—presented a problem: results obtained using different techniques disagree. What is worse, they disagree consistently. There have been numerous attempts to explain these discrepancies, but none has provided a satisfactory s…
Fundamental Properties of Stars Using Asteroseismology from Kepler and CoRoT and Interferometry from the CHARA Array
Kawaler, S. D.; Thompson, M. J.; Christensen-Dalsgaard, J. +37 more
We present results of a long-baseline interferometry campaign using the PAVO beam combiner at the CHARA Array to measure the angular sizes of five main-sequence stars, one subgiant and four red giant stars for which solar-like oscillations have been detected by either Kepler or CoRoT. By combining interferometric angular diameters, Hipparcos paral…
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