Search Publications
The ACS Nearby Galaxy Survey Treasury. X. Quantifying the Star Cluster Formation Efficiency of nearby Dwarf Galaxies
Johnson, L. Clifton; Fouesneau, Morgan; Seth, Anil C. +6 more
We study the relationship between the field star formation and cluster formation properties in a large sample of nearby dwarf galaxies. We use optical data from the Hubble Space Telescope and from ground-based telescopes to derive the ages and masses of the young (t age <~ 100 Myr) cluster sample. Our data provide the first constrain…
A Constant Limiting Mass Scale for Flat Early-type Galaxies from z ~ 1 to z = 0: Density Evolves but Shapes Do Not
Franx, Marijn; van der Wel, Arjen; Rix, Hans-Walter +1 more
We measure the evolution in the intrinsic shape distribution of early-type galaxies from z ~ 1 to z ~ 0 by analyzing their projected axis-ratio distributions. We extract a low-redshift sample (0.04 < z < 0.08) of early-type galaxies with very low star formation rates from the Sloan Digital Sky Survey, based on a color-color selection scheme …
Optical and Infrared Photometry of Globular Clusters in NGC 1399: Evidence for Color-Metallicity Nonlinearity
Jordán, Andrés; Peng, Eric W.; Ferrarese, Laura +3 more
We combine new Wide Field Camera 3 IR Channel (WFC3/IR) F160W (H 160) imaging data for NGC 1399, the central galaxy in the Fornax cluster, with archival F475W (g 475), F606W (V 606), F814W (I 814), and F850LP (z 850) optical data from the Advanced Camera for Surveys (ACS). The purely optical g…
Unveiling the Physical Properties and Kinematics of Molecular Gas in the Antennae Galaxies (NGC 4038/9) through High-resolution CO (J = 3-2) Observations
Tamura, Yoichi; Wilson, Christine D.; Yun, Min S. +12 more
We present a ~1'' (100 pc) resolution 12CO (3-2) map of the nearby intermediate-stage interacting galaxy pair NGC 4038/9 (the Antennae galaxies) obtained with the Submillimeter Array. We find that half the CO (3-2) emission originates in the overlap region where most of the tidally induced star formation had been previously found in sho…
Early-type Galaxies at z = 1.3. I. The Lynx Supercluster: Cluster and Groups at z = 1.3. Morphology and Color-Magnitude Relation
White, Richard L.; Illingworth, Garth D.; Koyama, Yusei +18 more
We confirm the detection of three groups in the Lynx supercluster, at z ≈ 1.3, through spectroscopic follow-up and X-ray imaging, and we give estimates for their redshifts and masses. We study the properties of the group galaxies compared to the two central clusters, RX J0849+4452 and RX J0848+4453. Using spectroscopic follow-up and multi-waveleng…
High-resolution XMM-Newton Spectroscopy of the Cooling Flow Cluster A3112
Loewenstein, Michael; Smith, Randall K.; Mushotzky, Richard +4 more
We examine high signal-to-noise XMM-Newton European Photon Imaging Camera (EPIC) and Reflection Grating Spectrometer (RGS) observations to determine the physical characteristics of the gas in the cool core and outskirts of the nearby rich cluster A3112. The XMM-Newton Extended Source Analysis Software data reduction and background modeling methods…
Titan's Bulk Composition Constrained by Cassini-Huygens: Implication for Internal Outgassing
Hersant, F.; Tobie, G.; Gautier, D.
In the present report, by using a series of data gathered by the Cassini-Huygens mission, we constrain the bulk content of Titan's interior for various gas species (CH4, CO2, CO, NH3, H2S, Ar, Ne, Xe), and we show that most of the gas compounds (except H2S and Xe) initially incorporated within…
Spitzer and Herschel Multiwavelength Characterization of the Dust Content of Evolved H II Regions
Bernard, J. -P.; Natoli, P.; Paladini, R. +8 more
We have analyzed a uniform sample of 16 evolved H II regions located in a 2° × 2° Galactic field centered at (l,b) = (30°, 0°) and observed as part of the Herschel Hi-GAL survey. The evolutionary stage of these H II regions was established using ancillary radio-continuum data. By combining Hi-GAL PACS (70 µm, 160 µm) and SPIRE (250 &mi…
A Stellar Dynamical Mass Measurement of the Black Hole in NGC 3998 from Keck Adaptive Optics Observations
Barth, Aaron J.; Sarzi, Marc; van den Bosch, Remco C. E. +1 more
We present a new stellar dynamical mass measurement of the black hole in the nearby, S0 galaxy NGC 3998. By combining laser guide star adaptive optics observations obtained with the OH-Suppressing Infrared Imaging Spectrograph on the Keck II telescope with long-slit spectroscopy from the Hubble Space Telescope and the Keck I telescope, we map out …
Herschel PACS and SPIRE Observations of Blazar PKS 1510-089: A Case for Two Blazar Zones
Szczerba, Ryszard; Nalewajko, Krzysztof; Madejski, Greg M. +5 more
We present the results of observations of blazar PKS 1510-089 with the Herschel Space Observatory PACS and SPIRE instruments, together with multiwavelength data from Fermi/LAT, Swift, SMARTS, and Submillimeter Array. The source was found in a quiet state, and its far-infrared spectrum is consistent with a power law with a spectral index of α ~= 0.…