Search Publications
Determining Titan's Spin State from Cassini RADAR Images
Iess, Luciano; Cassini RADAR Team; Stiles, Bryan W. +12 more
For some 19 areas of Titan's surface, the Cassini RADAR instrument has obtained synthetic aperture radar (SAR) images during two different flybys. The time interval between flybys varies from several weeks to two years. We have used the apparent misregistration (by 10-30 km) of features between separate flybys to construct a refined model of Titan…
The Extended HST Supernova Survey: The Rate of SNe Ia at z > 1.4 Remains Low
Riess, Adam G.; Strolger, Louis-Gregory; Dahlen, Tomas
We use the HST ACS imaging of the two GOODS fields during Cycles 11, 12, and 13 to derive the Type Ia supernova rate in four redshift intervals in the range 0.2 < z < 1.8. Compared to our previous results based on Cycle 11 observations only, we have increased the coverage of the search by a factor 2.7, making the total area searched equivale…
The Host Galaxy and Central Engine of the Dwarf Active Galactic Nucleus POX 52
Ho, Luis C.; Thornton, Carol E.; Barth, Aaron J. +2 more
We present new multiwavelength observations of the dwarf Seyfert 1 galaxy POX 52 in order to investigate the properties of the host galaxy and the active nucleus and to examine the mass of its black hole, previously estimated to be ~105 M⊙. HST ACS HRC images show that the host galaxy has a dwarf elliptical morphology (M…
Galaxy evolution in Hickson compact groups: the role of ram-pressure stripping and strangulation
Yun, Min S.; Ponman, Trevor J.; Verdes-Montenegro, Lourdes +2 more
Galaxies in compact groups tend to be deficient in neutral hydrogen compared to isolated galaxies of similar optical properties. In order to investigate the role played by a hot intragroup medium (IGM) for the removal and destruction of HI in these systems, we have performed a Chandra and XMM-Newton study of eight of the most HI deficient Hickson …
Simultaneous Multiwavelength Observations of the Blazar 1ES 1959+650 at a Low TeV Flux
Maraschi, L.; Tagliaferri, G.; Ghisellini, G. +144 more
We present the results from a multiwavelength campaign on the TeV blazar 1ES 1959+650, performed in 2006 May. Data from the optical, UV, soft- and hard-X-ray, and very high energy (VHE) gamma-ray (E > 100 GeV) bands were obtained with the Suzaku and Swift satellites, the MAGIC telescope, and other ground-based facilities. The source spectral en…
Hinode XRT observations of a long-lasting coronal sigmoid
Canfield, R. C.; McKenzie, D. E.
Aims:Coronal sigmoids are important sources of eruptions into interplanetary space, and a handful of models have been proposed to explain their characteristic S shape. However, the coronal X-ray images available to date have generally not had sufficient resolution to distinguish between these models. The goal of the present investigation is to det…
The VLA Survey of the Chandra Deep Field-South. I. Overview and the Radio Data
Tozzi, P.; Mainieri, V.; Rosati, P. +5 more
We report 20 and 6 cm VLA deep observations of the CDF-S including the Extended CDF-S. We discuss the radio properties of 266 cataloged radio sources, of which 198 are above a 20 cm completeness level reaching down to 43 µJy at the center of the field. Survey observations made at 6 cm over a more limited region cover the original CDF-S to a …
The Rotating Nuclear Star Cluster in NGC 4244
Caldwell, Nelson; Seth, Anil C.; Debattista, Victor P. +2 more
We present observations of the nuclear star cluster in the nearby edge-on spiral galaxy NGC 4244 using the Gemini Near-Infrared Integral Field Spectrograph (NIFS) with laser guide star adaptive optics. From a previous study of edge-on galaxies, this nuclear star cluster was found to be one of a sample of clusters that appear flattened along the pl…
Spitzer/MIPS 24 µm Observations of Galaxy Clusters: An Increasing Fraction of Obscured Star-forming Members from z = 0.02 to z = 0.83
Saintonge, Amélie; Tran, Kim-Vy H.; Holden, Bradford P.
We study the mid-infrared properties of 1315 spectroscopically confirmed members in eight massive (Mvirgtrsim 5 × 1014 M⊙) galaxy clusters covering the redshift range from 0.02 to 0.83. The selected clusters all have deep Spitzer/MIPS 24 µm observations, Hubble and ground-based photometry, and extensive redsh…
Hydrocarbons on Saturn's satellites Iapetus and Phoebe
Sotin, C.; Brown, R. H.; Baines, K. H. +24 more
Material of low geometric albedo ( p⩽0.1) is found on many objects in the outer Solar System, but its distribution in the saturnian satellite system is of special interest because of its juxtaposition with high-albedo ice. In the absence of clear, diagnostic spectral features, the composition of this low-albedo (or "dark") material is generally in…