Search Publications
Suppression of the Rhines effect and the location of vortices on Saturn
Showman, A. P.; Penny, A. B.; Choi, D. S.
Saturn's atmosphere contains numerous vortices that reside predominantly within specific localized latitude bands. Two-dimensional turbulence theory predicts that vortices which do form are readily destroyed as they interact with dispersive Rossby waves in a process called the “Rhines effect,” which acts to organize turbulent energy into alternati…
Jupiter’s South South Temperate Zone vortices: Observations and simulations
Dowling, Timothy E.; Morales-Juberías, Raúl; Brindle, Emily S.
The region in Jupiter's atmosphere with the highest density of anticyclonic spot-like vortices is the region known as the South South Temperate Zone (SSTZ), which is located between the eastward jet at ≈-42.9° latitude and the westward jet at ≈-39.2° latitude. We present a characterization of the spots found in this region based on ground-based an…
Photometric and Spectroscopic Study of the Delta Scuti Stars FH Cam, CU CVn and CC Lyn
Ogloza, W.; Conidis, G. J.; Gazeas, K. D. +1 more
Three short period (P ∼ 1 day) variable stars from the Hipparcos catalogue targets were observed after suspected misclassification as Beta Lyr eclipsing systems (Perryman et al. 1997), as no secondary component had been noticed in the inspection of their Broadening Functions (BFs) (Rucinski 2002). FH Cam is found to be a multiple star system with …
Acceleration of electrons in Titan's ionosphere
Khodachenko, M. L.; Rucker, H. O.; Panchenko, M. +2 more
A consideration of the acceleration mechanism which supplies the fast electrons to the source of Saturnian kilometric radiation (SKR) and an interpretation of the recently reported observational indications of the influence of Titan on the SKR are presented. The proposed mechanism operates by the effect of the different magnetization of the electr…
Multifrequency emission analysis of TeV blazars H 2356-309 and 1ES 1218+304
Zhang, Li; Tang, Yun-Yong; Dai, Zu-Cheng
The multiband nonthermal emissions in radio, X-ray, and very high-energy (VHE) γ-ray bands from two distant blazars, H 2356-309 and 1ES 1218+304, have been detected, and, especially from recent observations with the Suzaku, MAGIC and VERITAS telescopes, clearly reveal nonthermal power-law spectra. We study the broadband nonthermal spectra of the t…
Coronal Shocks Associated with Impulsive and Decaying Phases of Solar Flares
Shanmugaraju, A.; Vršnak, B.; Suresh, K. +1 more
We have analyzed a set of 147 metric Type II radio bursts observed by Culgoora radio spectrograph from November 1997 to December 2006. These events were divided into two sets: The first subset contains Type II events that started during the impulsive phase of the associated solar flares and the second subset contains those starting during the deca…
Quasistatic electric field structures and field-aligned currents in the polar cusp region
Jacobsen, K. S.; Moen, J. I.; Pedersen, A.
Cluster data have been examined for quasi-stationary electric field structures and field-aligned currents (FACs) in the vicinity of the dayside cusp region. We have related the measurements to the Region 1/Region 2 (R1/R2) current system and the cusp current system. It has been theoretically proposed that the dayside R1 current may be located on o…
V945 Centauri = HD 112409: a bright hot short-period binary in a triple system?
Aerts, C.; Prša, A.; Harmanec, P. +2 more
A detailed analysis of multicolour Geneva photometry and high-resolution echelle spectroscopy of the B8.5V star V945 Cen (HD 112409, V = 5.2 m) whose short-term periodic variability was first detected from the HIPPARCOS data, led to the finding that the object is an ellipsoidal variable and a close double-lined spectroscopic binary with a 0.6496° …
Using a global magnetohydrodynamic model to study the start of the substorm recovery phase
Baker, D. N.; Wiltberger, M.; Farr, N. L.
Magnetospheric substorms are a key manifestation of the transfer of energy from the solar wind to the Earth. Substorms consist of a loading of energy from the solar wind via magnetic reconnection and then a rapid release of that energy. One of the results of this energy release is the intense brightening of the aurora observed in the Earth's high-…
The X-ray Binary analogy to the first AGN QPO
Done, C.; Middleton, M.; Gierliński, M.
We examine the different QPOs seen in X-ray Binaries for an analogous signal to the first AGN QPO. Simple mass scaling rules out the low-frequency and standard high-frequency QPOs. However, the rather unique 67 Hz QPO of GRS 1915+105 scales to imply the source is accreting at around Eddington as supported by the SED. The 67 Hz QPO is seen when GRS…