Search Publications
The Energetics of Molecular Gas in NGC 891 from H2 and Far-infrared Spectroscopy
Boulanger, F.; Charmandaris, V.; Combes, F. +5 more
We have studied the molecular hydrogen energetics of the edge-on spiral galaxy NGC 891, using a 34 position map in the lowest three pure rotational H2 lines observed with the Spitzer Infrared Spectrograph. The S(0), S(1), and S(2) lines are bright with an extinction-corrected total luminosity of ~2.8 × 107 L sun, o…
Astrometric study of the relative motion of three stars with possible invisible companions based on homogeneous series obtained at Pulkovo with a 26-inch refractor
Kiyaeva, O. V.; Izmailov, I. S.; Gorynya, N. A.
We investigate the relative motion of three stars, ADS 7446, 9346, and 9701, based on long-term observations with the Pulkovo 26-inch refractor. The relative motion of all three stars shows a perturbation that could be produced by the gravitational influence of an invisible companion. For ADS 7446, we have determined the orbit of the photocenter w…
Saturn: Atmosphere, Ionosphere, and Magnetosphere
Ingersoll, Andrew P.; Gombosi, Tamas I.
The Cassini spacecraft has been in orbit around Saturn since 30 June 2004, yielding a wealth of data about the Saturn system. This review focuses on the atmosphere and magnetosphere and briefly outlines the state of our knowledge after the Cassini prime mission. The mission has addressed a host of fundamental questions: What processes control the …
Analyzing the Low State of EF Eridani with Hubble Space Telescope Ultraviolet Spectra
Holtzman, Jon; Walter, Frederick M.; Harrison, Thomas E. +10 more
Time-resolved spectra throughout the orbit of EF Eri during its low accretion state were obtained with the solar blind channel on the Advanced Camera for Surveys on board the Hubble Space Telescope. The overall spectral distribution exhibits peaks at 1500 and 1700 Å, while the UV light curves display a quasi-sinusoidal modulation over the binary o…
Linear radio structures in selected Seyfert galaxies
Richards, A. M. S.; Thean, A. H. C.; Pedlar, A. +1 more
High-resolution Multi-Element Radio Linked Interferometer Network 5-GHz observations of seven Seyfert galaxies, selected as the ones previously showing evidence of collimated ejection, have been compared with high-resolution Hubble Space Telescope data. A radio and optical/near-ultraviolet emission correlation is apparent in all the sources. The r…
The first Rosetta asteroid flyby
Ferri, Paolo; Accomazzo, Andrea; Hubault, Armelle +3 more
The International Rosetta Mission, a cornerstone mission of the European Space Agency Scientific Programme, was launched on 2 March 2004 on its 10 years journey towards a rendezvous with comet Churyumov-Gerasimenko. Once reached the comet nucleus in summer 2014, Rosetta will orbit it for about 1.5 years down to distances of a few kilometres and de…
Whistler propagation and modulation in the presence of nonlinear Alfvén waves
Goldstein, M. L.; Sharma, R. P.; Dwivedi, Navin Kumar +1 more
This paper presents the modulation of whistler waves due to linear interactions between a weak whistler signal and a pump kinetic Alfvén wave (KAW) in intermediate-β(me/mi ≪ β ≪ 1) plasmas (where β is the ratio of the ion sound speed to the Alfvén speed). As a consequence of ponderomotive nonlinearity, the pump KAW becomes fi…
Type-II Bursts in Meter and Deca - Hectometer Wavelengths and Their Relation to Flares and CMEs: II
Prakash, O.; Shanmugaraju, A.; Vršnak, Bojan +2 more
A study of the relationship between 38 type-II bursts recorded in meter and deca-hectometer (hereinafter m and DH) wavelength range and the associated flares and CMEs observed during the years 2000 - 2005 was carried out by Prakash et al. (2009). These events were divided into two classes: i) Class I, representing events where DH-type-II bursts ar…
Geology and Surface Processes on Titan
Sotin, Christophe; Tomasko, Martin G.; Keller, Horst Uwe +8 more
The surface of Titan has been revealed globally, if incompletely, by Cassini observations at infrared and radar wavelengths as well as locally by the instruments on the Huygens probe. Extended dune fields, lakes, mountainous terrain, dendritic erosion patterns and erosional remnants indicate dynamic surface processes. Valleys, small-scale gullies …
Kinematics and velocity ellipsoid of the F giants
Branham, Richard L., Jr.
To study the kinematics of the F giant stars (luminosity class III), proper motions taken from van Leeuwen's new reduction of the Hipparcos catalogue are used. 591 stars, of which 222 have radial velocities, were used in the final study. Semi-definite programming solves for the kinematical parameters such as the Oort constants and simultaneously f…