Search Publications
A Population of Weak Metal-Line Absorbers Surrounding the Milky Way
Richter, Philipp; Charlton, Jane C.; Fangano, Alessio P. M. +2 more
We report on the detection of a population of weak metal-line absorbers in the halo or nearby intergalactic environment of the Milky Way. Using high-resolution ultraviolet absorption-line spectra of bright quasars (QSO) obtained with the Space Telescope Imaging Spectrograph (STIS), along six sight lines we have observed unsaturated, narrow absorpt…
Hubble Space Telescope Optical Imaging of the Eroding Debris Disk HD 61005
Scherer, K.; Graham, James R.; Schneider, G. +7 more
We present Hubble Space Telescope optical coronagraphic polarization imaging observations of the dusty debris disk HD 61005. The scattered light intensity image and polarization structure reveal a highly inclined disk with a clear asymmetric, swept back component, suggestive of significant interaction with the ambient interstellar medium (ISM). Th…
Early-Type Galaxies in the PEARS Survey: Probing the Stellar Populations at Moderate Redshift
Hathi, Nimish P.; Koekemoer, Anton M.; Pirzkal, Nor +10 more
Using Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) slitless grism spectra from the PEARS program, we study the stellar populations of morphologically selected early-type galaxies in the GOODS North and South fields. The sample—extracted from a visual classification of the (v2.0) HST/ACS images and restricted to redshifts z > 0…
A Spitzer Study of 21 and 30 µm Emission in Several Galactic Carbon-Rich Protoplanetary Nebulae
Volk, Kevin; Kwok, Sun; Hrivnak, Bruce J.
We have carried out mid-infrared spectroscopy of seven Galactic protoplanetary nebulae (PPNs) using the Spitzer Space Telescope. They were observed from 10 to 36 µm at relatively high spectral resolution, R ≈ 600. The sample was chosen because they all gave some evidence in the visible of a carbon-rich chemistry. All seven of the sources sho…
Ion and electron superdiffusive transport in the interplanetary space
Zimbardo, Gaetano; Perri, Silvia
We study the propagation of energetic particles, accelerated by interplanetary shock waves, upstream of the shock. By using the appropriate propagator, we show that in the case of superdiffusive transport, the time profile of particles accelerated at a traveling planar shock is a power-law with slope 0<γ<1, at variance with the exponential p…
Design and In-Orbit Performance of the Suzaku Wide-Band All-Sky Monitor
Enoto, Teruaki; Yamaoka, Kazutaka; Endo, Akira +38 more
The plasma interaction of Enceladus: 3D hybrid simulations and comparison with Cassini MAG data
Dougherty, M. K.; Saur, J.; Glassmeier, K. -H. +4 more
We study the interaction of Saturn's small, icy moon Enceladus and its plume with the corotating magnetospheric plasma by means of a 3D hybrid simulation model, which treats the ions as individual particles and the electrons as a massless, charge-neutralizing fluid. We analyze systematically how Enceladus' internal conductivity and plasma absorpti…
Non-dipolar solar wind structure observed in the cycle 23/24 minimum
Tokumaru, M.; Hayashi, K.; Kojima, M. +1 more
Interplanetary scintillation (IPS) observations made in the Cycle 23/24 minimum using the Solar-Terrestrial Environment Laboratory (STEL) multi-station system indicated that during intervals the solar wind had a significantly non-dipolar structure that consisted of fast wind components at the poles and the equator and slower wind components in bet…
Composition and chemistry of Titan's thermosphere and ionosphere
Yelle, R. V.; Lavvas, P.; Vuitton, V.
Suzaku Observations of Local Ultraluminous Infrared Galaxies
Sanders, D. B.; Nakagawa, Takao; Veilleux, Sylvain +7 more
We report the results from our analysis of Suzaku X-ray Imaging Spectrometer (XIS) (0.5-10 keV) and Hard X-ray Detector (HXD)/PIN (15-40 keV) observations of five well-known local ultraluminous infrared galaxies: IRAS F05189 - 2524, IRAS F08572 + 3915, Mrk 273, PKS 1345 + 12, and Arp 220. The XIS observations of F05189 - 2524 and Mrk 273 reveal st…