Search Publications
Energetic particle sounding of the magnetopause: A contribution by Cluster/RAPID
Zong, Q. -G.; Daly, P. W.; Korth, A. +4 more
In this paper we present new results using Cluster/Research with Adaptive Particle Imaging Detectors (RAPID) energetic particle observations to remotely sound the high-latitude magnetopause in three dimensions. We demonstrate that energetic particle flux variations in the vicinity of the magnetopause (inside the magnetosphere) are mainly modulated…
XMM-Newton observations of warm absorbers in PG quasars
Page, M. J.; Branduardi-Raymont, G.; Córdova, F. A. +5 more
We present XMM-Newton European Photon Imaging Camera observations of warm absorbers in the quasars PG 1114+445 and PG 1309+355, both of which exhibit evidence for absorption by warm material in the line of sight. We find the absorption in PG 1114+445 to be in two phases, a `hot' phase with a log ionization parameter, ξ, of 2.57, and a `cooler' pha…
Intermediate-age globular clusters in early-type galaxies: Better age determinations by adding U-band observations to the V, I, K datasets
Kissler-Patig, M.; Hempel, M.
This paper represents an extension to a series of publications on combined optical and near-infrared photometry of globular cluster systems in early-type galaxies. Based on color-color diagrams the cumulative age distributions of their globular cluster systems have been derived and revealed intermediate age clusters in two galaxies, namely NGC 436…
XMM-Newton observation of the Seyfert 1 ESO 198-G24
Kaastra, J. S.; O'Brien, P. T.; Porquet, D. +3 more
We present the results from an XMM-Newton observation (January 24, 2001) of the bright Seyfert 1 galaxy
Observations of cosmic ray electrons and positrons during the early stages of the A- magnetic polarity epoch
Clem, John; Evenson, Paul
As part of our ongoing investigation of the charge sign dependence in solar modulation, we measured the cosmic ray positron abundance (0.8 GeV to 4.5 GeV) and electron flux (20 MeV to 4.5 GeV) on balloon flights from Lynn Lake, Manitoba during August 2002. We find that the decrease in the positron abundance observed in 2000 persists in 2002. The l…
Comparison OF Noise Properties Of GONG And MDI Time-Distance Helioseismic Data
Thompson, M. J.; Rajaguru, S. P.; Hughes, S. J.
The recently upgraded system of the ground-based Global Oscillation Network Group (GONG) network of helioseismic observatories has started to provide higher-resolution solar oscillation measurements suitable for local helioseismic studies. Selecting simultaneously observed regions on the Sun by both GONG and the space-borne Michelson Doppler Image…
Cumulants and symmetries in a trivariate normal mixture. A qualitative study of the local velocity distribution
Cubarsi, R.; Alcobé, S.
An alternative parameterization of a trivariate normal mixture for the stellar velocity distribution provides a set of constraint equations between global cumulants that are used to estimate characteristic constants of the mixture and population parameters. Under particular distribution symmetries these relationships become simpler and easy to eva…
Discovery of a new INTEGRAL source: IGR J19140+0951
Rodriguez, J.; Henri, G.; Petrucci, P. O. +5 more
IGR J19140+0951 (formerly known as IGR J19140+098) was discovered with the INTEGRAL satellite in March 2003. We report the details of the discovery, using an improved position for the analysis. We have performed a simultaneous study of the 5-100 keV JEM-X and ISGRI spectra from which we can distinguish two different states. From the results of our…
The Counterstreaming Instability in Dwarf Elliptical Galaxies with Off-Center Nuclei
Debattista, Victor P.; De Rijcke, Sven
In many nucleated dwarf elliptical galaxies (dE,N's), the nucleus is offset by a significant fraction of the scale radius with respect to the center of the outer isophotes. Using a high-resolution N-body simulation, we demonstrate that the nucleus can be driven off-center by the m=1 counterstreaming instability, which is strong in flattened stella…
Wolf-Rayet stars in M33 - I. Optical spectroscopy using CFHT-MOS
Drissen, Laurent; Crowther, Paul A.; Dessart, Luc +3 more
We have obtained spectroscopy of a large sample of Wolf-Rayet stars in M33 with the Canada-France-Hawaii Telescope Multi-Object Spectrograph (CFHT-MOS), including 26 WC stars, 15 WN stars and a WN/C star. In general, spectral types are merely refined, although the spectral type of X9 from Massey & Johnson is revised from WNL?+abs to WC4+abs, w…