Search Publications
Numerical Magnetohydrodynamic (MHD) Modeling of Coronal Mass Ejections (CMEs)
Plunkett, S. P.; Wu, S. T.; Andrews, M. D.
The Coronal Mass Ejection (CME) is arguably the most important discovery of solar eruptive phenomena in the 20th century. It is now also recognized that CMEs have great impact on the Earth's environment by inducing geomagnetic storms. Thus, development of simulation models to understand the physical mechanisms of CME initiation and propagation has…
On the nature of the hard X-ray source 4U 2206+54
Reig, P.; Negueruela, I.
The recent discovery of a ~ 9.5\:d period in the X-ray lightcurve of the massive X-ray binary
First XMM-Newton observations of a cataclysmic variable I: Timing studies of OY Car
Priedhorsky, W.; Pandel, D.; Ramsay, G. +9 more
We present XMM-Newton observations of the eclipsing, disc accreting, cataclysmic variable OY Car which were obtained as part of the performance verification phase of the mission. The star was observed 4 days after an outburst and then again 5 weeks later when it was in a quiescent state. There is a quasi-stable modulation of the X-rays at ~ 2240 s…
SOHO/SUMER observations and analysis of the hydrogen Lyman spectrum in solar prominences
Heinzel, P.; Vial, J. -C.; Schmieder, B. +1 more
The complete hydrogen Lyman spectrum in several prominences has been observed with the UV spectrometer SUMER on-board the SOHO, during the Joint Observing Programme 107, together with other space and ground-based observatories. Based on these observations, we are able to demonstrate, for the first time, that there exists a large variety of intensi…
Multi-colour light variation of AGB stars observed with ISO
Lebzelter, T.; Kerschbaum, F.; Lazaro, C.
New visual light curves and infrared multi-epoch photometry are presented for a sample of AGB-stars spectroscopically observed with ISO. While the ISO work is or will be presented elsewhere, the aim of this paper is to give an overview of the properties of the light change of the objects. This information is crucial for the interpretation of the v…
XMM-Newton observation of the Seyfert 1 galaxy Fairall 9
Gondoin, P.; Guainazzi, M.; Schartel, N. +2 more
We report an X-ray observation of the Fairall 9 Seyfert 1 galaxy performed in July 2000 with the EPIC cameras and Reflection Grating Spectrometers (RGS) on board the XMM-Newton observatory. Above 2 keV, the high signal to noise ratio of the EPIC spectra shows an emission line at 6.38+/-0.03 keV with a measured equivalent width of 120 eV. An absorp…
A search for possible interactions between ejections from GRS 1915+105 and the surrounding interstellar medium
Chaty, S.; Fuchs, Y.; Mirabel, I. F. +5 more
We have observed an extended region surrounding the first discovered galactic superluminal source GRS 1915+105, seeking evidence of interaction between the relativistic ejecta of that object and the interstellar medium. We find two radio sources axisymmetrically aligned along the sub-arcsecond relativistic ejecta of GRS 1915+105 and roughly 17amin…
MACHO 96-LMC-2: Lensing of a Binary Source in the Large Magellanic Cloud and Constraints on the Lensing Object
Alcock, C.; Allsman, R. A.; Alves, D. R. +21 more
We present photometry and analysis of the microlensing alert MACHO 96-LMC-2 (event LMC-14 in an earlier paper). This event was initially detected by the MACHO Alert System and subsequently monitored by the Global Microlensing Alert Network (GMAN). The ~3% photometry provided by the GMAN follow-up effort reveals a periodic modulation in the light c…
Spatial Structure of Simple Spiky Bursts at Microwave/Millimeter Wavelengths
Kundu, M. R.; White, S. M.; Shibasaki, K. +2 more
We present the results of a study of spatial structure of sources of microwave and millimeter bursts with simple spiky time profiles at 17 and 34 GHz, similar to those found to be common at 3 mm wavelength. These bursts are of short duration, with fast 2-4 s rise time to peak, followed by a rapid exponential decay. When mapped at high spatial reso…
The geometry of stellar motions in the nucleus region of the Ursa Major kinematic group
Vereshchagin, S. V.; Reva, V. G.; Chupina, N. V.
The structure of the central part of the UMa stellar kinematic group was considered according to the data from Hipparcos, Tycho and ACT catalogues. We have shown that in the space occupied by the nucleus there are several populations of stars. The first includes ten stars which are very compactly located in the proper motion diagram and have a nor…