Search Publications
Seasonal Changes in Titan's Surface Temperatures
Flasar, F. M.; Coustenis, A.; Jennings, D. E. +9 more
Seasonal changes in Titan's surface brightness temperatures have been observed by Cassini in the thermal infrared. The Composite Infrared Spectrometer measured surface radiances at 19 µm in two time periods: one in late northern winter (LNW; Ls = 335°) and another centered on northern spring equinox (NSE; Ls = 0°). In b…
Statistical characteristics of field-aligned currents in Saturn's nightside magnetosphere
Coates, A. J.; Dougherty, M. K.; Cowley, S. W. H. +3 more
During 2008, the Cassini spacecraft traversed Saturn's high-latitude field-aligned current systems on sequential north-south periapsis passes in the nightside magnetosphere. Two types of current systems have previously been identified, associated with antisymmetric azimuthal field signatures in the northern and southern hemispheres. The first exhi…
High ions towards white dwarfs: circumstellar line shifts and stellar temperature
Barstow, M. A.; Lallement, R.; Welsh, B. Y. +1 more
Aims: Our aim is to gain new insights into highly ionized gas towards nearby hot white dwarfs (WDs). The detection of absorption lines of highly ionized interstellar (IS) species in their spectra is the main diagnostic tool of the hot IS gas phase. This requires disentangling IS ions from photospheric or circumstellar (CS) ions, and thus thei…
Stream particles as the probe of the dust-plasma-magnetosphere interaction at Saturn
Kempf, S.; Postberg, F.; Srama, R. +5 more
We analyze the dynamics and composition of Saturnian stream particles measured by the Cosmic Dust Analyser (CDA) onboard the Cassini spacecraft. To reconstruct the dynamical properties of Saturnian stream particles, we adopt a backward tracing method with in situ solar wind measurements to filter out the influence of the interplanetary magnetic fi…
Ultraviolet Spectroscopy of Circumnuclear Star Clusters in M83
Leitherer, Claus; Chandar, Rupali; Wofford, Aida
We analyze archival HST/STIS/FUV-MAMA imaging and spectroscopy of 13 compact star clusters within the circumnuclear starburst region of M83, the closest such example. We compare the observed spectra with semi-empirical models, which are based on an empirical library of Galactic O and B stars observed with IUE, and with theoretical models, which ar…
A broad-band X-ray view of the warm absorber in radio-quiet quasar MR 2251-178
Turner, T. J.; Kraemer, S. B.; Fukazawa, Y. +6 more
We present the analysis of a new broad-band X-ray spectrum (0.6-180.0 keV) of the radio-quiet quasar MR 2251-178 which uses both Suzaku and Swift/Burst Alert Telescope data. In accordance with previous observations, we find that the general continuum can be well described by a power law with Γ= 1.6 and an apparent soft excess below 1 keV. Warm abs…
Plasmoid Releases in the Heliospheric Current Sheet and Associated Coronal Hole Boundary Layer Evolution
Sauvaud, J. -A.; Luhmann, J. G.; Farrugia, C. J. +10 more
As the heliospheric current sheet (HCS) is corotating past STEREO-B, near-Earth spacecraft ACE, Wind and Cluster, and STEREO-A over more than three days between 2008 January 10 and 14, we observe various sections of (near-pressure-balanced) flux-rope- and magnetic-island-type plasmoids in the associated heliospheric plasma sheet (HPS). The plasmoi…
Multiwavelength Observations of a Failed Flux Rope in the Eruption and Associated M-Class Flare from NOAA AR 11045
Filippov, B.; Erdélyi, R.; Kumar, Pankaj +2 more
We present the multiwavelength observations of a flux rope that was trying to erupt from NOAA AR 11045 and the associated M-class solar flare on 12 February 2010 using space-based and ground-based observations from TRACE, STEREO, SOHO/MDI, Hinode/XRT, and BBSO. While the flux rope was rising from the active region, an M1.1/2F class flare was trigg…
A comparison of space weather analysis techniques used to predict the arrival of the Earth-directed CME and its shockwave launched on 8 April 2010
Webb, D. F.; Möstl, C.; Farrugia, C. J. +10 more
The Earth-directed coronal mass ejection (CME) of 8 April 2010 provided an opportunity for space weather predictions from both established and developmental techniques to be made from near-real time data received from the SOHO and STEREO spacecraft; the STEREO spacecraft provide a unique view of Earth-directed events from outside the Sun-Earth lin…
The near-IR spectrum of Titan modeled with an improved methane line list
Bailey, Jeremy; Meadows, V. S.; Ahlsved, Linda
We have obtained spatially resolved spectra of Titan in the near-infrared J, H and K bands at a resolving power of ∼5000 using the near-infrared integral field spectrometer (NIFS) on the Gemini North 8 m telescope. Using recent data from the Cassini/Huygens mission on the atmospheric composition and surface and aerosol properties, we develop a mul…