Search Publications
The Absence of Adiabatic Contraction of the Radial Dark Matter Profile in the Galaxy Cluster A2589
Humphrey, Philip J.; Buote, David A.; Brighenti, Fabrizio +4 more
We present an X-ray analysis of the radial mass profile of the radio-quiet galaxy cluster A2589 between 0.015 and 0.25rvir, using an XMM-Newton observation. Except for a ~16 kpc shift of the X-ray center of the R=45-60 kpc annulus, A2589 possesses a remarkably symmetrical X-ray image and is therefore an exceptional candidate for precisi…
The Effects of Space Weathering at UV Wavelengths: S-Class Asteroids
Vilas, Faith; Hendrix, Amanda R.
We present evidence that space weathering manifests itself at near-UV wavelengths as a bluing of the spectrum, in contrast with the spectral reddening that has been seen at visible-near-IR wavelengths. Furthermore, the effects of space weathering at UV wavelengths tend to appear with less weathering than do the longer wavelength effects, suggestin…
GRB 060121: Implications of a Short-/Intermediate-Duration γ-Ray Burst at High Redshift
Sakamoto, T.; McBreen, S.; Pandey, S. B. +23 more
Since the discovery of the first short-population γ-ray burst (GRB) afterglows in 2005, the handful of observed events have been found to be embedded in nearby (z < 1), bright underlying galaxies. We present multiwavelength observations of GRB 060121, the first short burst observed to clearly outshine its host galaxy (by a factor >102
Cassini imaging of Saturn: Southern hemisphere winds and vortices
West, R. A.; Kennedy, M. R.; Porco, C. C. +4 more
High-resolution images of Saturn's southern hemisphere acquired by the Cassini Imaging Science Subsystem between February and October 2004 are used to create maps of cloud morphology at several wavelengths, to derive zonal winds, and to characterize the distribution, frequency, size, morphology, color, behavior, and lifetime of vortices. Nonequato…
An Optical Study of Stellar and Interstellar Environments of Seven Luminous and Ultraluminous X-Ray Sources
Chu, You-Hua; Wang, Q. Daniel; Gruendl, Robert A. +3 more
We have studied the stellar and interstellar environments of two luminous X-ray sources and five ultraluminous X-ray sources (ULXs) in order to gain insight into their nature. Archival Hubble Space Telescope images were used to identify the optical counterparts of the ULXs Ho IX X-1 and NGC 1313 X-2, and to make photometric measurements of the loc…
Companion Event and Precursor of the X17 Flare on 28 October 2003
Mandrini, C. H.; Schmieder, B.; Pariat, E. +3 more
A major two-ribbon X17 flare occurred on 28 October 2003, starting at 11:01 UT in active region NOAA 10486. This flare was accompanied by the eruption of a filament and by one of the fastest halo coronal mass ejections registered during the October-November 2003 strong activity period. We focus on the analysis of magnetic field (SOHO/MDI), chromos…
Planetary nebulae abundances and stellar evolution
Pottasch, S. R.; Bernard-Salas, J.
A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted f…
The Huygens-Hellas giant dike system on Mars: Implications for Late Noachian Early Hesperian volcanic resurfacing and climatic evolution
Head, J. W.; Neukum, G.; Wilson, L. +1 more
Two narrow, broadly arcuate, low ridges extend for 600 700 km in western Terra Tyrrhena, Mars, crosscut ancient Noachian terrain, and are associated with Early Hesperian plains, which cover ∼30% of Mars. Geological relationships suggest that the ridges represent near-surface erosional remnants of subsurface dikes, solidified magma-filled cracks th…
Petschek-Type Reconnection Exhausts in the Solar Wind Well beyond 1 AU: Ulysses
McComas, D. J.; Forsyth, R. J.; Gosling, J. T. +2 more
We have identified 91 Petschek-type exhausts associated with local, quasi-stationary magnetic reconnection in the solar wind in plasma and magnetic field data from the Ulysses spacecraft obtained over a wide range of heliocentric distances (1.4-5.4 AU) and latitudes (S79°-N65°). The characteristic signature of an exhaust was a brief (minutes) inte…
Multiplicity and Optical Excess across the Substellar Boundary in Taurus
Kraus, Adam L.; Hillenbrand, Lynne A.; White, Russel J.
We present the results of a high-resolution imaging survey of 22 brown dwarfs and very low mass stars in the nearby (~145 pc) young (~1-2 Myr) low-density star-forming region Taurus-Auriga. We obtained images with the Advanced Camera for Surveys High Resolution Channel on HST through the F555W (V), F775W (i'), and F850LP (z') filters. This survey …