Search Publications
Candels: The Evolution of Galaxy Rest-frame Ultraviolet Colors from z = 8 to 4
Papovich, Casey; Finkelstein, Steven L.; Dickinson, Mark +18 more
We study the evolution of galaxy rest-frame ultraviolet (UV) colors in the epoch 4 <~ z <~ 8. We use new wide-field near-infrared data in the Great Observatories Origins Deep Survey-South field from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble Ultra Deep Field (HUDF) 2009, and Early Release Science programs to s…
Keck Spectroscopy of Faint 3 < z < 8 Lyman Break Galaxies: Evidence for a Declining Fraction of Emission Line Sources in the Redshift Range 6 < z < 8
Richard, Johan; Stark, Daniel P.; Ellis, Richard S. +5 more
Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with the Wide Field Camera 3 on board the Hubble Space Telescope, we present new evidence for a reversal in the redshift-dependent fraction of star-forming galaxies with detectable Lyman alpha (Lyα) emission in the redshift range 6.3 < z < 8.8. Our…
What Turns Galaxies Off? The Different Morphologies of Star-forming and Quiescent Galaxies since z ~ 2 from CANDELS
Papovich, Casey; Bell, Eric F.; Giavalisco, Mauro +21 more
We use HST/WFC3 imaging from the CANDELS Multi-Cycle Treasury Survey, in conjunction with the Sloan Digital Sky Survey, to explore the evolution of galactic structure for galaxies with stellar masses >3 × 1010 M ⊙ from z = 2.2 to the present epoch, a time span of 10 Gyr. We explore the relationship between rest-frame optic…
The Characteristic Star Formation Histories of Galaxies at Redshifts z ~ 2-7
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +3 more
A large sample of spectroscopically confirmed star-forming galaxies at redshifts 1.4 <= z spec <= 3.7, with complementary imaging in the near- and mid-IR from the ground and from the Hubble Space Telescope and Spitzer Space Telescope, is used to infer the average star formation histories (SFHs) of typical galaxies from z ~ 2 to 7.…
Lower-luminosity Galaxies Could Reionize the Universe: Very Steep Faint-end Slopes to the UV Luminosity Functions at z >= 5-8 from the HUDF09 WFC3/IR Observations
Trenti, M.; Oesch, P. A.; Carollo, C. M. +7 more
The HUDF09 data are the deepest near-IR observations ever, reaching to 29.5 mag. Luminosity functions (LFs) from these new HUDF09 data for 132 z ~ 7 and z ~ 8 galaxies are combined with new LFs for z ~ 5-6 galaxies and the earlier z ~ 4 LF to reach to very faint limits (<0.05 L* z = 3). The faint-end slopes α are steep: -1.79 ± 0.12 …
Identification of Kinetic Alfvén Wave Turbulence in the Solar Wind
Bale, S. D.; Chen, C. H. K.; Mozer, F. S. +4 more
The nature of small-scale turbulent fluctuations in the solar wind is investigated using a comparison of Cluster magnetic and electric field measurements to predictions arising from models consisting of either kinetic Alfvén waves or whistler waves. The electric and magnetic field properties of these waves from linear theory are used to construct …
Multiple Stellar Populations in 47 Tucanae
Di Criscienzo, M.; Anderson, J.; Milone, A. P. +16 more
We use Hubble Space Telescope (HST) and ground-based imaging to study the multiple populations of 47 Tucanae (47 Tuc), combining high-precision photometry with calculations of synthetic spectra. Using filters covering a wide range of wavelengths, our HST photometry splits the main sequence into two branches, and we find that this duality is repeat…
The M31 Velocity Vector. II. Radial Orbit toward the Milky Way and Implied Local Group Mass
Anderson, Jay; van der Marel, Roeland P.; Beaton, Rachael L. +5 more
We determine the velocity vector of M31 with respect to the Milky Way and use this to constrain the mass of the Local Group, based on Hubble Space Telescope proper-motion measurements of three fields presented in Paper I. We construct N-body models for M31 to correct the measurements for the contributions from stellar motions internal to M31. This…
On the Cluster Physics of Sunyaev-Zel'dovich and X-Ray Surveys. I. The Influence of Feedback, Non-thermal Pressure, and Cluster Shapes on Y-M Scaling Relations
Bond, J. R.; Battaglia, N.; Sievers, J. L. +1 more
The utility of large Sunyaev-Zel'dovich (SZ) surveys for determining cosmological parameters from cluster abundances is limited by the theoretical uncertainties in the integrated SZ-flux-to-mass relation, Y-M. We explore how non-thermal pressure and the anisotropic shape of the gas distribution of the intracluster medium (ICM) impacts Y-M scaling …
The Dependence of Quenching upon the Inner Structure of Galaxies at 0.5 <= z < 0.8 in the DEEP2/AEGIS Survey
Bell, Eric F.; Kocevski, Dale D.; Koekemoer, Anton M. +25 more
The shutdown of star formation in galaxies is generally termed "quenching." Quenching may occur through a variety of processes, e.g., active galactic nucleus (AGN) feedback, stellar feedback, or the shock heating of gas in the dark matter halo. However, which mechanism(s) is, in fact, responsible for quenching is still in question. This paper addr…