Search Publications
Size Evolution of the Most Massive Galaxies at 1.7 < z < 3 from GOODS NICMOS Survey Imaging
Dickinson, Mark; Conselice, Christopher J.; Bouwens, Rychard J. +3 more
We measure the sizes of 82 massive (M >= 1011 M⊙) galaxies at 1.7 <= z <= 3 utilizing deep HST NICMOS data taken in the GOODS North and South fields. Our sample is almost an order of magnitude larger than previous studies at these redshifts, providing the first statistical study of massive galaxy sizes at z > 2, c…
Evolution of the Bar Fraction in COSMOS: Quantifying the Assembly of the Hubble Sequence
Mobasher, Bahram; Schinnerer, Eva; Ellis, Richard S. +13 more
We have analyzed the redshift-dependent fraction of galactic bars over 0.2 < z < 0.84 in 2157 luminous face-on spiral galaxies from the COSMOS 2 deg2 field. Our sample is an order of magnitude larger than that used in any previous investigation, and is based on substantially deeper imaging data than that available from earlier wid…
Bulge Formation by the Coalescence of Giant Clumps in Primordial Disk Galaxies
Elmegreen, Bruce G.; Elmegreen, Debra Meloy; Bournaud, Frédéric
Gas-rich disks in the early universe are highly turbulent and have giant star-forming clumps. Models suggest that the clumps form by gravitational instabilities, and if they resist disruption by star formation, then they interact, lose angular momentum, and migrate to the center to form a bulge. Here we study the properties of the bulges formed by…
Cosmic Variance and Its Effect on the Luminosity Function Determination in Deep High-z Surveys
Trenti, M.; Stiavelli, M.
We study cosmic variance in deep high-redshift surveys and its influence on the determination of the luminosity function for high-redshift galaxies. For several survey geometries relevant for Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) instruments, we characterize the distribution of the galaxy number counts. This is obtaine…
The c2d Spitzer Spectroscopic Survey of Ices around Low-Mass Young Stellar Objects. I. H2O and the 5-8 µm Bands
Augereau, J. -C.; Stapelfeldt, K. R.; van Dishoeck, E. F. +23 more
To study the physical and chemical evolution of ices in solar-mass systems, a spectral survey is conducted of a sample of 41 low-luminosity YSOs (L ~ 0.1-10 L⊙) using 3-38 µm Spitzer and ground-based spectra. The sample is complemented with previously published Spitzer spectra of background stars and with ISO spectra of well-studi…
The ACS Virgo Cluster Survey. XV. The Formation Efficiencies of Globular Clusters in Early-Type Galaxies: The Effects of Mass and Environment
Jordán, Andrés; Tonry, John L.; Côté, Patrick +8 more
The fraction of stellar mass contained in globular clusters (GCs), also measured by number as the specific frequency, is a fundamental quantity that reflects both a galaxy's early star formation and its entire merging history. We present specific frequencies, luminosities, and mass fractions for the globular cluster systems of 100 early-type galax…
UV Excess Measures of Accretion onto Young Very Low Mass Stars and Brown Dwarfs
Herczeg, Gregory J.; Hillenbrand, Lynne A.
Low-resolution spectra from 3000 to 9000 Å of young low-mass stars and brown dwarfs were obtained with LRIS on Keck I. The excess UV and optical emission arising in the Balmer and Paschen continua yields mass accretion rates ranging from 2 × 10-12 to 10-8 M⊙ yr-1. These results are compared with HST STIS…
The Initial-Final Mass Relation: Direct Constraints at the Low-Mass End
Kelson, Daniel D.; Rich, R. Michael; Hansen, Brad M. S. +3 more
The initial-final mass relation represents a mapping between the mass of a white dwarf remnant and the mass that the hydrogen-burning main-sequence star that created it once had. The empirical relation thus far has been constrained using a sample of ~40 stars in young open clusters, ranging in initial mass from ~2.75 to 7 M⊙, and shows …
The Structure of the Local Interstellar Medium. IV. Dynamics, Morphology, Physical Properties, and Implications of Cloud-Cloud Interactions
Redfield, Seth; Linsky, Jeffrey L.
We present an empirical dynamical model of the LISM based on 270 radial velocity measurements for 157 sight lines toward nearby stars. Physical parameter measurements (i.e., temperature, turbulent velocity, depletions) are available for 90 components, or one-third of the sample, enabling initial characterizations of the physical properties of LISM…
FIREWORKS U38-to-24 µm Photometry of the GOODS Chandra Deep Field-South: Multiwavelength Catalog and Total Infrared Properties of Distant Ks-selected Galaxies
van Dokkum, Pieter G.; Franx, Marijn; Labbé, Ivo +4 more
We present a Ks-selected catalog, dubbed FIREWORKS, for the Chandra Deep Field-South (CDF-S) containing photometry in the U38, B435, B, V, V606, R, i775, I, z850, J, H, Ks, [3.6 µm], [4.5 µm], [5.8 µm], [8.0 µm], and MIPS [24 µm] bands. The i…