Search Publications
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…
Jet-powered Molecular Hydrogen Emission from Radio Galaxies
Appleton, P. N.; Ogle, Patrick; Antonucci, Robert +5 more
H2 pure-rotational emission lines are detected from warm (100-1500 K) molecular gas in 17/55 (31% of) radio galaxies at redshift z < 0.22 observed with the Spitzer IR Spectrograph. The summed H2 0-0 S(0)-S(3) line luminosities are L(H2) = 7 × 1038-2 × 1042 erg s-1, yielding warm …