Search Publications
The Three-dimensional Circumstellar Environment of SN 1987A
Crotts, Arlin P. S.; Lawrence, Stephen S.; Sugerman, Ben E. K. +2 more
Surrounding SN 1987A is a three-ring nebula attributed to interacting stellar winds, yet no model has successfully reproduced this system. Fortunately, the progenitor's mass-loss history can be reconstructed using light echoes, in which scattered light from the supernova traces the three-dimensional morphology of its circumstellar dust. In this pa…
Calculating the Thermal Structure of Solar Active Regions in Three Dimensions
Linker, Jon A.; Mikić, Zoran; Mok, Yung +1 more
We describe a technique to obtain the temperature and density distribution in an active region for a specified plasma heating model. The technique can be applied in general to determine the magnetic field and thermal structure self-consistently. For simplicity, we illustrate the application of this technique in the limit of small plasma β, in whic…
GEMS: Which Galaxies Dominate the z~0.7 Ultraviolet Luminosity Density?
Heymans, C.; Wolf, C.; Barden, M. +14 more
We combine high-resolution images from GEMS with redshifts and spectral energy distributions from COMBO-17 to explore the morphological types of galaxies that dominate the z~0.7 UV luminosity density. We analyzed rest-frame 280 nm and V-band luminosities of 1483 galaxies with 0.65<z<0.75, combining these with visual morphological classificat…
Asteroid target selection for the new Rosetta mission baseline. 21 Lutetia and 2867 Steins
Barbieri, C.; Barucci, M. A.; Fornasier, S. +8 more
The new Rosetta mission baseline to the comet 67P/Churyumov-Gerasimenko includes two asteroid fly-bys. To help in target selection we studied all the candidates of all the possible scenarios. Observations have been carried out at ESO-NTT (La Silla, Chile), TNG (Canaries), and NASA-IRTF (Hawaii) telescopes, in order to determine the taxonomy of all…
Star Formation Rates in Cooling Flow Clusters: A UV Pilot Study with Archival XMM-Newton Optical Monitor Data
Mushotzky, R.; Hicks, A. K.
We have analyzed XMM-Newton Optical Monitor UV (180-400 nm) data for a sample of 33 galaxies. Thirty are cluster member galaxies, and nine are central cluster galaxies (CCGs) in cooling flow clusters having mass deposition rates between 8 and 525 Msolar yr-1. By comparing the ratio of UV to 2MASS J-band fluxes, we find a sign…
Discovery of a flank caldera and very young glacial activity at Hecates Tholus, Mars
HRSC Co-Investigator Team; Head, James W.; Greeley, Ronald +8 more
The majority of volcanic products on Mars are thought to be mafic and effusive. Explosive eruptions of basic to ultrabasic chemistry are expected to be common, but evidence for them is rare and mostly confined to very old surface features. Here we present new image and topographic data from the High Resolution Stereo Camera that reveal previously …
Molecular Hydrogen in the Damped Lyα Absorber of Q1331+170
Ge, Jian; Meyer, David M.; Bechtold, Jill +1 more
We used HST STIS to obtain the spectrum of molecular hydrogen associated with the damped Lyα system at zabs=1.7765 toward the quasar Q1331+170 at zem=2.084. Strong H2 absorption was detected, with a total H2 column density of N(H2)=(4.45+/-0.36)×1019 cm-2. The molecular h…
In situ observations of a solar wind compression-induced hot plasma injection in Saturn's tail
Coates, A. J.; Krupp, N.; Dougherty, M. K. +5 more
During the Saturn orbit insertion (SOI) fly-through of the Cassini spacecraft, Saturn's magnetosphere underwent a significant corotating interaction region (CIR) related compression. Such compressions have recently been suggested to produce rapid bursts of tail reconnection, enhanced Saturn kilometric radiation (SKR), and consequent auroral dynami…
Detection of Radial Surface Brightness Fluctuations and Color Gradients in Elliptical Galaxies with the Advanced Camera for Surveys
Blakeslee, John P.; Mei, Simona; Cantiello, Michele +3 more
We study surface brightness fluctuations (SBFs) in a sample of eight elliptical galaxies using the Advanced Camera for Surveys (ACS) Wide Field Channel (WFC) data drawn from the Hubble Space Telescope archive. SBF magnitudes in the F814W bandpass and galaxy colors from F814W, F435W, and F606W images, when available, are presented. Galaxy surface b…
The XMM-Newton view of PG quasars. II. Properties of the Fe K_α line
Guainazzi, M.; Schartel, N.; Rodríguez-Pascual, P. M. +3 more
The properties of the fluorescence Fe Kα emission lines of a sample of 38 quasars (QSOs) observed with XMM-Newton are studied. These objects are included in the optically selected sample from the Palomar-Green (PG) Bright Quasar Survey with an X-ray luminosity 1.3 × 1043 < L2-10~keV < 5.1 × 1045 erg s-1<…