Search Publications
The Sand Seas of Titan: Cassini RADAR Observations of Longitudinal Dunes
Lorenz, R. D.; Stiles, B.; Kelleher, K. +37 more
The most recent Cassini RADAR images of Titan show widespread regions (up to 1500 kilometers by 200 kilometers) of near-parallel radar-dark linear features that appear to be seas of longitudinal dunes similar to those seen in the Namib desert on Earth. The Ku-band (2.17-centimeter wavelength) images show ~100-meter ridges consistent with duneforms…
Spitzer Observations of Massive, Red Galaxies at High Redshift
Daddi, E.; Elbaz, D.; Le Floc'h, E. +18 more
We study massive galaxies at z~1-3.5 using HST optical imaging, ground-based near-IR imaging, and Spitzer observations at 3-24 µm. From Ks-selected galaxies in the ~=130 arcmin2 GOODS-S field, we identify 153 distant red galaxies (DRGs) with (J-Ks)Vega>=2.3. This sample is approximately complete…
The GOODS-MUSIC sample: a multicolour catalog of near-IR selected galaxies in the GOODS-South field
Fontana, A.; Vanzella, E.; Grazian, A. +6 more
Aims. We present a high quality multiwavelength (from 0.3 to 8.0 µm) catalog of the large and deep area in the GOODS Southern Field covered by the deep near-IR observations obtained with the ESO VLT. Methods. The catalog is entirely based on public data: in our analysis, we have included the F435W, F606W, F775W and F850LP ACS images, the JHK…
Identification of a Dynamic Atmosphere at Enceladus with the Cassini Magnetometer
Russell, C. T.; Dougherty, M. K.; Khurana, K. K. +4 more
The Cassini magnetometer has detected the interaction of the magnetospheric plasma of Saturn with an atmospheric plume at the icy moon Enceladus. This unanticipated finding, made on a distant flyby, was subsequently confirmed during two follow-on flybys, one very close to Enceladus. The magnetometer data are consistent with local outgassing activi…
The Proper Motion of the Large Magellanic Cloud Using HST
Drake, A. J.; Geha, M.; van der Marel, Roeland P. +4 more
We present a measurement of the systemic proper motion of the Large Magellanic Cloud (LMC) from astrometry with the High Resolution Camera (HRC) of the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST). We observed LMC fields centered on 21 background QSOs that were discovered from their optical variability in the MACHO databas…
Dry Mergers in GEMS: The Dynamical Evolution of Massive Early-Type Galaxies
Bell, Eric F.; Somerville, Rachel S.; Wisotzki, Lutz +16 more
We have used the 28'×28' Hubble Space Telescope image mosaic from the GEMS (Galaxy Evolution from Morphology and SEDs) survey in conjunction with the COMBO-17 photometric redshift survey to constrain the incidence of major mergers between spheroid-dominated galaxies with little cold gas (dry mergers) since z=0.7. A set of N-b…
On the X-ray, optical emission line and black hole mass properties of local Seyfert galaxies
Cappi, M.; Iwasawa, K.; Barcons, X. +5 more
We investigate the relation between X-ray nuclear emission, optical emission line luminosities and black hole masses for a sample of 47 Seyfert galaxies. The sample, which has been selected from the Palomar optical spectroscopic survey of nearby galaxies (Ho et al. 1997a, ApJS, 112, 315), covers a wide range of nuclear powers, from L2-10 keV<…
The Direct Detection of Lyman Continuum Emission from Star-forming Galaxies at z~3
Pettini, Max; Erb, Dawn K.; Shapley, Alice E. +2 more
We present the results of rest-frame UV spectroscopic observations of a sample of 14 z~3 star-forming galaxies in the SSA 22a field. These spectra are characterized by unprecedented depth in the Lyman continuum region. For the first time, we have detected escaping ionizing radiation from individual galaxies at high redshift, with 2 of the 14 objec…
ISM properties in low-metallicity environments
Madden, S. C.; Galliano, F.; Sauvage, M. +1 more
We present new ISOCAM mid-infrared spectra of three starbursting nearby dwarf galaxies, NGC 1569, NGC 1140 and II Zw 40 and the 30 Dor region of the LMC and explore the properties of the ISM in low-metallicity environments, also using additional sources from the literature. We analyse the various components of the ISM probed by the mid-infrared ob…
Strong and Weak Lensing United. III. Measuring the Mass Distribution of the Merging Galaxy Cluster 1ES 0657-558
Bradač, Maruša; Schrabback, Tim; Jones, Christine +7 more
The galaxy cluster 1ES 0657-558 (z=0.296) is remarkably well suited for addressing outstanding issues in both galaxy evolution and fundamental physics. We present a reconstruction of the mass distribution from both strong and weak gravitational lensing data. Multicolor, high-resolution HST ACS images allow detection of many more arc candidates tha…