Search Publications
A Revised Age for Upper Scorpius and the Star Formation History among the F-type Members of the Scorpius-Centaurus OB Association
Mamajek, Eric E.; Pecaut, Mark J.; Bubar, Eric J.
We present an analysis of the ages and star formation history of the F-type stars in the Upper Scorpius (US), Upper Centaurus-Lupus (UCL), and Lower Centaurus-Crux (LCC) subgroups of Scorpius-Centaurus (Sco-Cen), the nearest OB association. Our parent sample is the kinematically selected Hipparcos sample of de Zeeuw et al., restricted to the 138 F…
The Evolving Interstellar Medium of Star-forming Galaxies since z = 2 as Probed by Their Infrared Spectral Energy Distributions
Daddi, E.; Elbaz, D.; Béthermin, M. +11 more
Using data from the mid-infrared to millimeter wavelengths for individual galaxies and for stacked ensembles at 0.5 < z < 2, we derive robust estimates of dust masses (M dust) for main-sequence (MS) galaxies, which obey a tight correlation between star formation rate (SFR) and stellar mass (M *), and for starbursting ga…
UV-continuum Slopes at z ~ 4-7 from the HUDF09+ERS+CANDELS Observations: Discovery of a Well-defined UV Color-Magnitude Relationship for z >= 4 Star-forming Galaxies
Trenti, M.; Oesch, P. A.; Carollo, C. M. +8 more
Ultra-deep Advanced Camera for Surveys (ACS) and WFC3/IR HUDF+HUDF09 data, along with the wide-area GOODS+ERS+CANDELS data over the CDF-S GOODS field, are used to measure UV colors, expressed as the UV-continuum slope β, of star-forming galaxies over a wide range of luminosity (0.1L* z = 3 to 2L* z = 3) at high redshift (z ~ …
Can Minor Merging Account for the Size Growth of Quiescent Galaxies? New Results from the CANDELS Survey
Treu, Tommaso; Ellis, Richard S.; Newman, Andrew B. +1 more
The presence of extremely compact galaxies at z ~ 2 and their subsequent growth in physical size has been the cause of much puzzlement. We revisit the question using deep infrared Wide Field Camera 3 data to probe the rest-frame optical structure of 935 galaxies selected with 0.4 < z < 2.5 and stellar masses M * > 1010.7
Spectroscopic Confirmation of Three z-dropout Galaxies at z = 6.844-7.213: Demographics of Lyα Emission in z ~ 7 Galaxies
Ono, Yoshiaki; Ouchi, Masami; Dickinson, Mark +10 more
We present the results of our ultra-deep Keck/DEIMOS spectroscopy of z-dropout galaxies in the Subaru Deep Field and Great Observatories Origins Deep Survey's northern field. For 3 out of 11 objects, we detect an emission line at ~1 µm with a signal-to-noise ratio of ~10. The lines show asymmetric profiles with high weighted skewness values,…
CANDELS: Constraining the AGN-Merger Connection with Host Morphologies at z ~ 2
Bell, Eric F.; Giavalisco, Mauro; Grogin, Norman A. +35 more
Using Hubble Space Telescope/WFC3 imaging taken as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, we examine the role that major galaxy mergers play in triggering active galactic nucleus (AGN) activity at z ~ 2. Our sample consists of 72 moderate-luminosity (L X ~ 1042-44 erg s-1) AGNs …
Smooth(er) Stellar Mass Maps in CANDELS: Constraints on the Longevity of Clumps in High-redshift Star-forming Galaxies
Barro, Guillermo; Bell, Eric F.; Ferguson, Henry C. +22 more
We perform a detailed analysis of the resolved colors and stellar populations of a complete sample of 323 star-forming galaxies (SFGs) at 0.5 < z < 1.5 and 326 SFGs at 1.5 < z < 2.5 in the ERS and CANDELS-Deep region of GOODS-South. Galaxies were selected to be more massive than 1010 M ⊙ and have specific star for…
Evolution of Magnetic Field and Energy in a Major Eruptive Active Region Based on SDO/HMI Observation
Liu, Yang; Hayashi, Keiji; Sun, Xudong +4 more
We report the evolution of the magnetic field and its energy in NOAA active region 11158 over five days based on a vector magnetogram series from the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO). Fast flux emergence and strong shearing motion led to a quadrupolar sunspot complex that produced several major er…
Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function
Cushing, Michael C.; Kirkpatrick, J. Davy; Gelino, Christopher R. +12 more
We present the discovery of another seven Y dwarfs from the Wide-field Infrared Survey Explorer (WISE). Using these objects, as well as the first six WISE Y dwarf discoveries from Cushing et al., we further explore the transition between spectral types T and Y. We find that the T/Y boundary roughly coincides with the spot where the J - H colors of…
The Flat Transmission Spectrum of the Super-Earth GJ1214b from Wide Field Camera 3 on the Hubble Space Telescope
Fortney, Jonathan J.; Désert, Jean-Michel; Charbonneau, David +7 more
Capitalizing on the observational advantage offered by its tiny M dwarf host, we present Hubble Space Telescope/Wide Field Camera 3 (WFC3) grism measurements of the transmission spectrum of the super-Earth exoplanet GJ1214b. These are the first published WFC3 observations of a transiting exoplanet atmosphere. After correcting for a ramp-like instr…