Search Publications
Dust-plasma interaction through magnetosphere-ionosphere coupling in Saturn's plasma disk
Gurnett, Donald A.; Kurth, William S.; Wahlund, Jan-Erik +4 more
The ion bulk speeds in the equatorial region of Saturn's inner magnetosphere, according to data from the Langmuir Probe (LP) on board the Cassini spacecraft, are about 60% of the ideal co-rotation speed; the ion speeds are between the co-rotation and Keplerian speeds (Holmberg et al., Ion densities and velocities in the inner plasma torus of Satur…
Dichromatic dark matter
Su, Meng; Zhao, Yue; Bai, Yang
Both the robust INTEGRAL 511 keV gamma-ray line and the recent tentative hint of the 135 GeV gamma-ray line from Fermi-LAT have similar signal morphologies, and may be produced from the same dark matter annihilation. Motivated by this observation, we construct a dark matter model to explain both signals and to accommodate the two required annihila…
Evidence for a short period of hydrologic activity in Newton crater, Mars, near the Hesperian-Amazonian transition
Howard, A. D.; Moore, J. M.; Parsons, R. A.
Hesperian/Amazonian-aged valleys and alluvial fans distributed in regional clusters throughout the southern middle- to low-latitudes were formed during a period of fluvial runoff and erosion which acted over a smaller spatial and temporal scale than the older, "classical" Martian valley networks dated to the Noachian-Hesperian boundary. In order t…
Comparison of general circulation model atmospheric wave simulations with wind observations of venusian mesosphere
Aoki, Shohei; Kasaba, Yasumasa; Nakagawa, Hiromu +5 more
Simulations from our venusian general circulation model (GCM) forcing the presence of planetary-scale waves and mesoscale gravity waves were compared with infrared (IR) heterodyne observations of Doppler wind velocities in the venusian mesospheric altitude region (110 km). Observations confirmed the strong short-term variations in the venusian mes…
Radiative transfer modelling of dust in IRAS 18333-2357: the only planetary nebula in the metal-poor globular cluster M22
Parthasarathy, M.; Ita, Y.; Muthumariappan, C.
We report results from our 1D radiative transfer modelling of dust in the hydrogen-deficient planetary nebula IRAS 18333-2357 located in the globular cluster M22. A spectral energy distribution was constructed from archival UV, optical and IR data including Akari photometry at its 18, 65, 90, 140 and 160 µm bands. An archival Spitzer spectru…
Witnessing the Differential Evolution of Disk Galaxies in Luminosity and Size via Gravitational Lensing
Crampton, David; Simard, Luc; Peng, Chien +1 more
We take advantage of the magnification in size and flux of a galaxy provided by gravitational lensing to analyze the properties of 62 strongly lensed galaxies from the Sloan Lens ACS (SLACS) Survey. The sample of lensed galaxies spans a redshift range of 0.20 <= z <= 1.20 with a median redshift of z = 0.61. We use the lens modeling code LENS…
Joint Suzaku and XMM-Newton Spectral Analysis of the Southwest Cygnus Loop
Leahy, Denis; Hassan, Mohammed
We carry out a joint spectral analysis of the Cygnus Loop using data from all six detectors combined from Suzaku and XMM-Newton. This had not been done before, but if a spectral model is physically realistic, it is required that it be consistent with data from different instruments. Thus, our results are an important verification of spectral model…
Formation of a penumbra in a decaying sunspot
Puschmann, K. G.; Mathew, S. K.; Beck, C. +2 more
Context. Penumbrae are an important characteristic of sunspots, whose formation is intricately related to the nature of sub-photospheric magnetic fields.
Aims: We study the formation of a penumbra in a decaying sunspot and compare its properties with those seen during the development of a proto-spot.
Methods: High-resolution spectropolar…
Strong Temporal Variation Over One Saturnian Year: From Voyager to Cassini
West, Robert A.; Baines, Kevin H.; Nixon, Conor A. +14 more
Here we report the combined spacecraft observations of Saturn acquired over one Saturnian year (~29.5 Earth years), from the Voyager encounters (1980-81) to the new Cassini reconnaissance (2009-10). The combined observations reveal a strong temporal increase of tropic temperature (~10 Kelvins) around the tropopause of Saturn (i.e., 50 mbar), which…
A submillimetre-bright z ~ 3 overdensity behind a z ~ 1 supercluster revealed by SCUBA-2 and Herschel.
Gladders, M. D.; Ivison, R. J.; Yee, H. K. C. +8 more
We present a wide-field (30 arcmin diameter) 850 µm Submillimetre Common-User Bolometer Array-2 map of the spectacular three-component merging supercluster, RCS 231953+00, at z = 0.9. The brightest submillimetre galaxy (SMG) in the field (S850 ≈ 12 mJy) is within 30 arcsec of one of the cluster cores (RCS 2319-C), and is likely to…