Search Publications
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 …
On the light echo in V838 Mon
Tylenda, R.
We present a theoretical outline of the light echo phenomenon and results of simple numerical simulations and we study the available images of the light echo in V838 Mon obtained with HST. An investigation of the observed expansion of the light echo leads us to conclude that the distance to V838 Mon is ⪆5 kpc. From an analysis of the inner bright …
XMM-Newton observations of the INTEGRAL X-ray transient IGR J17544-2619
Parmar, A. N.; Kuulkers, E.; González-Riestra, R. +2 more
On September 17, 2003 INTEGRAL discovered a bright transient source 3° from the Galactic Center,
UV-photoprocessing of interstellar ice analogs: Detection of hexamethylenetetramine-based species
Schutte, W. A.; Greenberg, J. M.; Muñoz Caro, G. M. +2 more
The physical conditions governing the dense cloud environment are reproduced in a high vacuum experimental setup at low temperature T ≈ 12 K. The accretion and photoprocessing of ices on grain surfaces is simulated by depositing an ice layer on a cold finger, while it is irradiated by ultraviolet (UV) photons. After irradiation the sample is slowl…