Search Publications
Coronal Mass Ejection Dynamics Regarding Radial and Expansion Speeds
Dal Lago, Alisson; Rigozo, Nivaor R.; Nordeman, D. J. R.
A new technique for the detection of coronal mass ejection (CME) speeds using image processing was applied. This technique permits us to determine the CME dynamics: radial and expansion distances, velocities, and accelerations. The CME dynamics is determined by the selection of a radial direction in a given Large Angle and Spectroscopic Coronagrap…
The thermal structure of sunspots from ring diagram analysis
Basu, Sarbani; Baldner, Charles S.; Bogart, Richard S.
We present a large sample of 264 active regions from solar cycle 23, analysed using ring diagrams. The frequencies of these rings are inverted to determine the thermal structure (sound speed and adiabatic index) of these regions as a function of radius. The large sample allows us to describe in a statistically significant way how the thermal prope…
X-Ray Spectroscopy of AS1101 with Chandra, XMM-Newton, and ROSAT: Bandpass Dependence of the Temperature Profile and Soft Excess Emission
Bonamente, Massimiliano; Nevalainen, Jukka
We present spatially resolved spectroscopy of the galaxy cluster AS1101, also known as Sèrsic 159-03, with Chandra, XMM-Newton, and ROSAT, and investigate the presence of soft X-ray excess emission above the contribution from the hot intracluster medium. In earlier papers we reported an extremely bright soft excess component that reached 100% of t…
Nongravitational Forces on Comets: An Extension of the Standard Model
Mysen, E.; Aksnes, K.
The accuracy of comet orbit computations is limited by uncertain knowledge of the recoil force due to outgassing from the nuclei. The standard model assumes an exponential dependence of the force on distance from the Sun. This variable force times constants A 1, A 2, and A 3 represents the radial, transverse, and n…
Systematic differences in position and proper-motion between the PPMX and UCAC3 catalogs
Zhu, Zi; Liu, Jia-Cheng; Hu, Bo
Considered to be extensions of the Hipparcos reference system, PPMX and UCAC3 are two of the most important astrometric catalogs released in current years. Extensive analyses of these two large catalogs have been made in order to determine the local and overall systematic biases. The regional and magnitude dependent differences in stellar position…
XMM-Newton observation of the eclipsing binary Algol
Chen, Li; Aschenbach, Bernd; Lu, Fang-Jun +1 more
We present an XMM-Newton observation of the eclipsing binary Algol which contains an X-ray dark B8V primary and an X-ray bright K2IV secondary. The observation covered the optical secondary eclipse and captured an X-ray flare that was eclipsed by the B star. The XMM-Newton European Photon Imaging Camera and Reflection Grating Spectrometer spectra …
Implementation of the Earth-based planetary radio occultation inversion technique
Ping, JinSong; Zhang, SuJun; Han, TingTing +2 more
The planetary radio occultation technique is one of the earliest suggested and achieved methods to detect the planetary atmosphere, and has been conducted by almost every deep space planetary probe. The principles, modules, inversion results and primary analysis of the SHAO Planetary Occultation observation Processing system (SPOPs) are presented …
Pi 2 waves simultaneously observed by Cluster and CPMN ground-based magnetometers near the plasmapause
André, M.; Lucek, E. A.; Ohtani, S. +6 more
We have analyzed an event on 14 February 2003 in which Cluster satellites and the CPMN ground magnetometer chain made simultaneous observations of a Pi 2 pulsation along the same meridian. Three of the four Cluster satellites were located outside the plasmasphere, while the other one was located within the plasmasphere. By combining the multipoint…
A search for X-ray sources around WR 22 in the Carina region
Gosset, E.; Nazé, Y.; Rauw, G. +2 more
We present the results of a deep search for X-ray sources in a circular field of 30' in diameter situated around WR 22 in the Carina region and observed with the XMM-Newton observatory. This field is broadly located to the west of the main part of the Carina nebula. On the basis of six pointings (nominal exposure time: 10 ks each) centred on the W…
Flares Producing Well-organized Post-flare Arcades (Slinkies) Have Early Precursors
Berger, T.; Frank, Z.; Ryutova, M. P. +1 more
Exploding loop systems producing X-ray flares often, but not always, bifurcate into a long-living, well-organized system of multi-threaded loop arcades resembling solenoidal slinkies. The physical conditions that cause or prevent this process are not known. To address this problem, we examined most of the major (X-class) flares that occurred durin…