Search Publications
A Population of Massive, Luminous Galaxies Hosting Heavily Dust-obscured Gamma-Ray Bursts: Implications for the Use of GRBs as Tracers of Cosmic Star Formation
Cenko, S. B.; Bloom, J. S.; Filippenko, A. V. +13 more
We present observations and analysis of the host galaxies of 23 heavily dust-obscured gamma-ray bursts (GRBs) observed by the Swift satellite during the years 2005-2009, representing all GRBs with an unambiguous host-frame extinction of AV > 1 mag from this period. Deep observations with Keck, Gemini, Very Large Telescope, Hubble Spa…
Stellar Velocity Dispersion Measurements in High-luminosity Quasar Hosts and Implications for the AGN Black Hole Mass Scale
Ferrarese, L.; Martini, P.; Peterson, B. M. +7 more
We present new stellar velocity dispersion measurements for four luminous quasars with the Near-Infrared Integral Field Spectrometer instrument and the ALTAIR laser guide star adaptive optics system on the Gemini North 8 m telescope. Stellar velocity dispersion measurements and measurements of the supermassive black hole (BH) masses in luminous qu…
Gravitational Lens Models Based on Submillimeter Array Imaging of Herschel-selected Strongly Lensed Sub-millimeter Galaxies at z > 1.5
Maiolino, R.; Pérez-Fournon, I.; Ivison, R. J. +46 more
Strong gravitational lenses are now being routinely discovered in wide-field surveys at (sub-)millimeter wavelengths. We present Submillimeter Array (SMA) high-spatial resolution imaging and Gemini-South and Multiple Mirror Telescope optical spectroscopy of strong lens candidates discovered in the two widest extragalactic surveys conducted by the …
The Changing Lyα Optical Depth in the Range 6 < z < 9 from the MOSFIRE Spectroscopy of Y-dropouts
Stiavelli, Massimo; Schmidt, Kasper B.; Treu, Tommaso +2 more
We present the MOSFIRE spectroscopy of 13 candidate z ~ 8 galaxies selected as Y-dropouts as part of the Brightest of Reionization Galaxies pure parallel survey. We detect no significant Lyα emission (our median 1σ rest-frame equivalent width sensitivity is in the range 2-16 Å). Using the Bayesian framework derived in a previous paper, we perform …
The sizes, masses and specific star formation rates of massive galaxies at 1.3 < z < 1.5: strong evidence in favour of evolution via minor mergers
McLure, R. J.; Dunlop, J. S.; Jarvis, M. J. +12 more
We report the results of a comprehensive study of the relationship between galaxy size, stellar mass and specific star formation rate (sSFR) at redshifts 1.3 < z < 1.5. Based on a mass-complete (M⋆ ≥ 6 × 1010 M⊙), spectroscopic sample from the UK Infrared Deep Sky Survey (UKIDSS) Ultradeep Survey, with accura…
An Intensely Star-forming Galaxy at z ~ 7 with Low Dust and Metal Content Revealed by Deep ALMA and HST Observations
Ono, Yoshiaki; Ouchi, Masami; Kurono, Yasutaka +10 more
We report deep ALMA observations complemented by associated Hubble Space Telescope (HST) imaging for a luminous (m UV = 25) galaxy, "Himiko," at a redshift of z = 6.595. The galaxy is remarkable for its high star formation rate, 100 M ⊙ yr-1, which has been securely estimated from our deep HST and Spitzer photometr…
A Young Protoplanet Candidate Embedded in the Circumstellar Disk of HD 100546
Amara, Adam; Meyer, Michael R.; Girard, Julien H. +3 more
We present high-contrast observations of the circumstellar environment of the Herbig Ae/Be star HD 100546. The final 3.8 µm image reveals an emission source at a projected separation of 0.''48 ± 0.''04 (corresponding to ~47 ± 4 AU) at a position angle of 8.°9 ± 0.°9. The emission appears slightly extended with a point source component with a…
The UV continua and inferred stellar populations of galaxies at z ≃ 7-9 revealed by the Hubble Ultra-Deep Field 2012 campaign
Bowler, R. A. A.; McLure, R. J.; Dunlop, J. S. +16 more
We use the new ultra-deep, near-infrared imaging of the Hubble Ultra-Deep Field (HUDF) provided by our UDF12 Hubble Space Telescope (HST) Wide Field Camera 3/IR campaign to explore the rest-frame ultraviolet (UV) properties of galaxies at redshifts z > 6.5. We present the first unbiased measurement of the average UV power-law index, <β>, …
Direct Evidence for a Fast Coronal Mass Ejection Driven by the Prior Formation and Subsequent Destabilization of a Magnetic Flux Rope
Patsourakos, S.; Stenborg, G.; Vourlidas, A.
Magnetic flux ropes play a central role in the physics of coronal mass ejections (CMEs). Although a flux-rope topology is inferred for the majority of coronagraphic observations of CMEs, a heated debate rages on whether the flux ropes pre-exist or whether they are formed on-the-fly during the eruption. Here, we present a detailed analysis of extre…
The Stellar Initial Mass Function of Ultra-faint Dwarf Galaxies: Evidence for IMF Variations with Galactic Environment
Ferguson, Henry C.; Brown, Thomas M.; Geha, Marla +8 more
We present constraints on the stellar initial mass function (IMF) in two ultra-faint dwarf (UFD) galaxies, Hercules and Leo IV, based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. The Hercules and Leo IV galaxies are extremely low luminosity (MV = -6.2, -5.5), metal-poor (lang[Fe/H]rang = -2.4, -2.5) systems that h…