Search Publications
Monte Carlo simulations of the halo white dwarf population
Burkert, A.; Torres, S.; Isern, J. +1 more
The interpretation of microlensing results towards the Large Magellanic Cloud (LMC) still remains controversial. While white dwarfs have been proposed to explain these results and, hence, to contribute significantly to the mass budget of our Galaxy, there are also several constraints on the role played by white dwarfs. In this paper we analyze sel…
EUVE observations of the helium glow: Interstellar and solar parameters
Lallement, R.; Lemoine, M.; Vallerga, J. +2 more
We present new observations of the diffuse He I 58.4 nm background recorded in 1998 and 2000 by the Extreme Ultraviolet Explorer (EUVE). This emission is due to resonant scattering of the solar EUV radiation by interstellar and geocoronal helium. Depending on the geometry and relative velocity, a fraction of the interstellar helium glow can be abs…
Arrival time of halo coronal mass ejections in the vicinity of the Earth
Gopalswamy, N.; Lara, A.; Manoharan, P. K. +1 more
We describe an empirical model to predict the 1-AU arrival time of halo CMEs. This model is based on the effective acceleration described by Gopalswamy et al. (\cite{Gopalswamy00}a, Geophys. Res. Lett., 27, 145). We verify the Helios/Pioneer Venus Orbiter(PVO) estimation of the effective acceleration profile (Gopalswamy et al. \cite{Gopalswamy01}a…
Spectral types and masses of white dwarfs in globular clusters
Heber, U.; Zoccali, M.; Koester, D. +4 more
White dwarfs in globular clusters offer additional possibilities to determine distances and ages of globular clusters, provided their spectral types and masses are known. We therefore started a project to obtain spectra of white dwarfs in the globular clusters NGC 6397 and NGC 6752. All observed white dwarfs show hydrogen-rich spectra and are ther…
XMM-Newton observation of the Seyfert 1.8 ESO 113-G010: Discovery of a highly redshifted iron line at 5.4 keV
Turner, T. J.; Uttley, P.; Porquet, D. +1 more
We present a spectral analysis of the Seyfert 1.8
L183 (L134N) Revisited. II. The dust content
Miville-Deschênes, M. -A.; Lagache, G.; Pagani, L. +6 more
We present here a complete dust map of
The nuclei of comets 126P/IRAS and 103P/Hartley 2
Jorda, L.; Lamy, P.; Groussin, O. +1 more
We report the detection of the nucleus of 126P/IRAS and 103P/Hartley 2 with the Infrared Camera of the Infrared Space Observatory (ISOCAM). 126P/IRAS was observed on 12 November 1996, when it was at r_h=1.71 AU from the Sun and Δ=1.32 AU from the Earth. 103P/Hartley 2 was observed on 5 February 1998, when it was at r_h=1.21 AU from the Sun and Δ=0…
Long-term variability in the X-ray emission of RX J0720.4-3125
de Vries, C. P.; Vink, J.; Verbunt, F. +1 more
We detect a gradual, long-term change in the shape of the X-ray spectrum of the isolated neutron star RX J0720.4-3125, such that the spectrum of the source can no longer be described as a blackbody spectrum. The change is accompanied by an energy-dependent change in the pulse profile. If the X-ray emission is influenced by the magnetic field of th…
Properties of the background of EPIC-pn onboard XMM-Newton
Freyberg, M. J.; Matsushita, K.; Takahashi, I. +2 more
We have investigated the background properties of EPIC-pn onboard XMM-Newton to establish the background subtraction method. Count rates of the background vary violently by two orders of magnitude at the maximum, while during the most quiet period, these are stable within 8% at a 1σ level. The overall spectrum is dominated by particle events above…
The dust environment of comet 67P/Churyumov-Gerasimenko
Rauer, H.; Fulle, M.; Barbieri, C. +4 more
The new target of the ESA Rosetta Mission is comet 67P/Churyumov-Gerasimenko, which passed its last perihelion on 18 August 2002 and was well observed from fall 2002 to spring 2003. Its most prominent feature was a thin dust tail, which is best fitted by the Neck-Line model. Fits of the whole tail provide the dust environment of 67P during a year …