Search Publications
The BOSS Emission-Line Lens Survey. II. Investigating Mass-density Profile Evolution in the SLACS+BELLS Strong Gravitational Lens Sample
Brownstein, Joel R.; Schlegel, David J.; Weaver, Benjamin A. +8 more
We present an analysis of the evolution of the central mass-density profile of massive elliptical galaxies from the SLACS and BELLS strong gravitational lens samples over the redshift interval z ≈ 0.1-0.6, based on the combination of strong-lensing aperture mass and stellar velocity-dispersion constraints. We find a significant trend toward steepe…
The nature of the Compton-thick X-ray reprocessor in NGC 4945
Yaqoob, Tahir
We present an exhaustive methodology for fitting Compton-thick X-ray reprocessor models to obscured active galactic nuclei (AGNs) and for interpreting the results. We focus on the MYTORUS model but also include some analysis from other models. The models are applied specifically to Suzaku, BeppoSAX and Swift Burst Alert Telescope spectra of the Se…
An HST/WFC3-IR Morphological Survey of Galaxies at z = 1.5-3.6. I. Survey Description and Morphological Properties of Star-forming Galaxies
Erb, Dawn K.; Shapley, Alice E.; Steidel, Charles C. +3 more
We present the results of a 42-orbit Hubble Space Telescope Wide-Field Camera 3 (HST/WFC3) survey of the rest-frame optical morphologies of star-forming galaxies with spectroscopic redshifts in the range z = 1.5-3.6. The survey consists of 42 orbits of F160W imaging covering ~65 arcmin2 distributed widely across the sky and reaching a d…
The Structures and Total (Minor + Major) Merger Histories of Massive Galaxies up to z ~ 3 in the HST GOODS NICMOS Survey: A Possible Solution to the Size Evolution Problem
Conselice, Christopher J.; Bluck, Asa F. L.; Mortlock, Alice +4 more
We investigate the total major (>1:4 by stellar mass) and minor (>1:100 by stellar mass) merger history of a population of 80 massive (M * > 1011 M ⊙) galaxies at high redshifts (z = 1.7-3). We utilize extremely deep and high-resolution Hubble Space Telescope H-band imaging from the GOODS NICMOS Survey, wh…
Multi-wavelength Observations of the Enduring Type IIn Supernovae 2005ip and 2006jd
Morrell, Nidia; Fransson, Claes; Hjorth, Jens +19 more
We present an observational study of the Type IIn supernovae (SNe IIn) 2005ip and 2006jd. Broadband UV, optical, and near-IR photometry, and visual-wavelength spectroscopy of SN 2005ip complement and extend upon published observations to 6.5 years past discovery. Our observations of SN 2006jd extend from UV to mid-infrared wavelengths, and like SN…
The properties of the star-forming interstellar medium at z = 0.84-2.23 from HiZELS: mapping the internal dynamics and metallicity gradients in high-redshift disc galaxies
Smail, Ian; Swinbank, A. M.; Geach, J. E. +5 more
We present adaptive optics assisted, spatially resolved spectroscopy of a sample of nine Hα-selected galaxies at z = 0.84-2.23 drawn from the HiZELS narrow-band survey. These galaxies have star formation rates of 1-27 M⊙ yr-1 and are therefore representative of the typical high-redshift star-forming population. Our ∼kpc-scale…
Feedback from Mass Outflows in Nearby Active Galactic Nuclei. I. Ultraviolet and X-Ray Absorbers
Kraemer, S. B.; Crenshaw, D. M.
We present an investigation into the impact of feedback from outflowing UV and X-ray absorbers in nearby (z < 0.04) active galactic nuclei (AGNs). From studies of the kinematics, physical conditions, and variability of the absorbers in the literature, we calculate the possible ranges in the total mass outflow rate (\dot{M}_{out}) and kinetic lu…
A critical analysis of the ultraviolet continuum slopes (β) of high-redshift galaxies: no evidence (yet) for extreme stellar populations at z > 6
McLure, R. J.; Dunlop, J. S.; Cirasuolo, M. +4 more
Following the discovery of the first significant samples of galaxies at z > 6.5 with Wide Field Camera 3/Infra-Red (WFC3/IR) on board Hubble Space Telescope (HST), it has been claimed that the faintest high-redshift galaxies display extremely blue ultraviolet (UV) continuum slopes, with a UV power-law index β≃-3 (where fλ∝λβ
Persistent Doppler Shift Oscillations Observed with Hinode/EIS in the Solar Corona: Spectroscopic Signatures of Alfvénic Waves and Recurring Upflows
De Pontieu, Bart; McIntosh, Scott W.; Tian, Hui +4 more
Using data obtained by the EUV Imaging Spectrometer on board Hinode, we have performed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of oscillations from February to April in 2007. One type is found at loop footpoint regions, with a dominant period around 1…
Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members. II. Age dependencies and new insights
Grundahl, F.; Milone, A. P.; Stello, D. +11 more
Context. Models of stellar structure and evolution can be constrained by measuring accurate parameters of detached eclipsing binaries in open clusters. Multiple binary stars provide the means to determine helium abundances in these old stellar systems, and in turn, to improve estimates of their age.
Aims: In the first paper of this series, we…