Search Publications
The ACS Fornax Cluster Survey. VIII. The Luminosity Function of Globular Clusters in Virgo and Fornax Early-type Galaxies and Its Use as a Distance Indicator
Jordán, Andrés; Infante, Leopoldo; Tonry, John L. +8 more
We use a highly homogeneous set of data from 132 early-type galaxies in the Virgo and Fornax clusters in order to study the properties of the globular cluster luminosity function (GCLF). The globular cluster system of each galaxy was studied using a maximum likelihood approach to model the intrinsic GCLF after accounting for contamination and comp…
A Deep Hubble Space Telescope Search for Escaping Lyman Continuum Flux at z ~ 1.3: Evidence for an Evolving Ionizing Emissivity
Dickinson, Mark; Ferguson, Henry C.; Giavalisco, Mauro +10 more
We have obtained deep Hubble Space Telescope far-UV images of 15 starburst galaxies at z ~ 1.3 in the GOODS fields to search for escaping Lyman continuum (LyC) photons. These are the deepest far-UV images (m AB = 28.7, 3σ, 1'' diameter) over this large an area (4.83 arcmin2) and provide some of the best escape fraction constr…
Eight γ-ray Pulsars Discovered in Blind Frequency Searches of Fermi LAT Data
Caraveo, P. A.; de Luca, A.; Abdo, A. A. +34 more
We report the discovery of eight γ-ray pulsars in blind frequency searches of ~650 source positions using the Large Area Telescope (LAT), on board the Fermi Gamma-ray Space Telescope. We present the timing models, light curves, and detailed spectral parameters of the new pulsars. PSRs J1023-5746, J1044-5737, J1413-5205, J1429-5911, and J1954+2836 …
The NGC 404 Nucleus: Star Cluster and Possible Intermediate-mass Black Hole
Caldwell, Nelson; Neumayer, Nadine; Olsen, Knut +8 more
We examine the nuclear morphology, kinematics, and stellar populations in nearby S0 galaxy NGC 404 using a combination of adaptive optics assisted near-IR integral-field spectroscopy, optical spectroscopy, and Hubble Space Telescope imaging. These observations enable study of the NGC 404 nucleus at a level of detail possible only in the nearest ga…
The ACS LCID Project. III. The Star Formation History of the Cetus dSph Galaxy: A Post-reionization Fossil
Dolphin, A. E.; Hidalgo, S. L.; Mayer, L. +12 more
We use deep HST/ACS observations to calculate the star formation history (SFH) of the Cetus dwarf spheroidal (dSph) galaxy. Our photometry reaches below the oldest main-sequence turnoffs, which allows us to estimate the age and duration of the main episode of star formation in Cetus. This is well approximated by a single episode that peaked roughl…
Coexisting Flux Rope and Dipped Arcade Sections Along One Solar Filament
Aulanier, G.; Bommier, V.; Schmieder, B. +4 more
We compute the three-dimensional magnetic field of an active region in order to study the magnetic configuration of active region filaments. The nonlinear force-free field model is adopted to compute the magnetic field above the photosphere, where the vector magnetic field was observed by THEMIS/MTR on 2005 May 27. We propose a new method to remov…
Spectacular X-ray Tails, Intracluster Star Formation, and ULXs in A3627
Forman, W.; Sun, M.; Nulsen, P. E. J. +5 more
We present the discovery of spectacular double X-ray tails associated with ESO 137-001 and a possibly heated X-ray tail associated with ESO 137-002, both late-type galaxies in the closest rich cluster Abell 3627. A deep Chandra observation of ESO 137-001 allows us for the first time to examine the spatial and spectral properties of such X-ray tail…
The Lack of Intense Lyα in Ultradeep Spectra of z = 7 Candidates in GOODS-S: Imprint of Reionization?
Maiolino, R.; Dickinson, M.; Giavalisco, M. +10 more
We present ultradeep optical spectroscopy obtained with FORS2 on the Very Large Telescope (VLT) of seven Lyman-break galaxy (LBG) candidates at z>6.5 selected in the GOODS-S field from Hawk-I/VLT and WFC3/HST imaging. For one galaxy we detect a low significance emission line (S/N <= 7), located at λ = 9691.5 ± 0.5 Å and with flux 3.4 × 10
A Multi-color Optical Survey of the Orion Nebula Cluster. II. The H-R Diagram
Panagia, N.; Robberto, M.; Da Rio, N. +4 more
We present a new analysis of the stellar population of the Orion Nebula Cluster (ONC) based on multi-band optical photometry and spectroscopy. We study the color-color diagrams in BVI, plus a narrowband filter centered at 6200 Å, finding evidence that intrinsic color scales valid for main-sequence dwarfs are incompatible with the ONC in the M spec…
The Great Observatories Origins Deep Survey: Constraints on the Lyman Continuum Escape Fraction Distribution of Lyman-break Galaxies at 3.4 < z < 4.5
Stern, D.; Dickinson, M.; Giavalisco, M. +14 more
We use ultra-deep ultraviolet VLT/VIMOS intermediate-band and VLT/FORS1 narrowband imaging in the GOODS Southern field to derive limits on the distribution of the escape fraction (f esc) of ionizing radiation for L >= L* z=3 Lyman-break galaxies (LBGs) at redshift 3.4-4.5. Only one LBG, at redshift z = 3.795, is detected i…