Search Publications
The SMART-1 lunar impact
Foing, B. H.; Burchell, M. J.; Robin-Williams, R.
The SMART-1 spacecraft impacted the Moon on 3rd September 2006 at a speed of 2 km s -1 and at a very shallow angle of incidence (∼1°). The resulting impact crater is too small to be viewed from the Earth; accordingly, the general crater size and shape have been determined here by laboratory impact experiments at the same speed and angle…
Spectroscopic identifications of SWIRE sources in ELAIS-N1
Valtchanov, I.; Morrison, G.; Georgakakis, A. +6 more
We present the largest spectroscopic follow-up performed in SWIRE ELAIS-N1. We were able to determine redshifts for 289 extragalactic sources. The values of spectroscopic redshifts of the latter have been compared with the estimated values from our photometric redshift code with very good agreement between the two for both galaxies and quasars. Si…
Watershed modeling in the Tyrrhena Terra region of Mars
Crown, David A.; Mest, Scott C.; Harbert, William
Watershed analyses from high-resolution image (Viking, Mars Orbiter Camera, and Thermal Emission Imaging System) and topographic (Mars Orbiter Laser Altimeter [MOLA]) data are used to qualitatively and quantitatively characterize highland fluvial systems and analyze the role of water in the evolution of Tyrrhena Terra (13°S-30°S, 265°W-280°W), Mar…
Discovery of water vapour in the carbon star V Cygni from observations with Herschel/HIFI
Waters, L. B. F. M.; Olofsson, H.; Marston, A. P. +25 more
We report the discovery of water vapour toward the carbon star V Cygni. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 111-000 para-water transition at 1113.3430 GHz in the upper sideband of the Band 4b receiver. The observed spectral line profile is nearly parabolic, but with a slight asymm…
Searching for Diffuse Nonthermal X-Rays from the Superbubbles N11 and N51D in the Large Magellanic Cloud
Yamaguchi, H.; Bamba, A.; Sawada, M.
We report on observations of the superbubbles (SBs) N11 and N51D in the Large Magellanic Cloud (LMC) with Suzaku and XMM-Newton. The interior of both SBs exhibits diffuse X-ray emission, which is well represented by thin thermal plasma models with a temperature of 0.2-0.3 keV. The presence of nonthermal emission, claimed in previous works, is much…
Modeling anomalous cosmic ray oxygen gradients over successive solar cycles
Potgieter, M. S.; Strauss, R. D.
Cosmic ray drift directions depend both on the charge of the particle population under consideration, as well as the heliospheric magnetic field polarity which oscillates within a ∼22 year cycle. The differences in the cosmic ray drift patterns between successive solar cycles manifest themselves in the sign of the latitudinal cosmic ray gradient. …
Infrared laboratory absorbance spectra of olivine: using classical dispersion analysis to extract peak parameters
Speck, A. K.; Dijkstra, C.; Pitman, K. M. +1 more
Laboratory measurements quantifying the effect of Fe substituting for Mg in olivine are needed to distinguish compositional from temperature, grain size and grain shape effects in observational data. To address this need, we study room temperature absorption spectra of a large suite of olivines evenly spaced across Mg and Fe compositions. We apply…
Mid-cycle Changes in Eta Carinae
Humphreys, Roberta M.; Davidson, Kris; Mehner, Andrea +1 more
In late 2006, ground-based photometry of η Car plus the Homunculus showed an unexpected decrease in its integrated apparent brightness, an apparent reversal of its long-term brightening. Subsequent Hubble Space Telescope (HST)/WFPC2 photometry of the central star in the near-UV showed that this was not a simple reversal. This multi-wavelength phot…
M31 Pixel Lensing Event OAB-N2: A Study of the Lens Proper Motion
Gould, A.; Nucita, A.; Mancini, L. +13 more
We present an updated analysis of the M31 pixel lensing candidate event OAB-N2 previously reported by Calchi Novati et al. Here we take advantage of new data both astrometrical and photometrical. For astrometry: using archival 4 m KPNO and Hubble Space Telescope/WFPC2 data we perform a detailed analysis of the event source whose result, although n…
Predicted colors and flux densities of protostars in the Herschel PACS and SPIRE filters
Megeath, S. T.; Osorio, M.; Furlan, E. +7 more
Upcoming surveys with the Herschel Space Observatory will yield far-IR photometry of large samples of young stellar objects, which will require careful interpretation. We investigate the color and luminosity diagnostics based on Herschel broad-band filters to identify and discern the properties of low-mass protostars. We compute a grid of 2016 pro…