Search Publications
Discovery of 1323 s pulsations from RX J0103.6-7201: The longest period X-ray pulsar in the SMC
Pietsch, W.; Haberl, F.
XMM-Newton archival observations of the Be/X-ray binary candidate revealed pulsations with a period of ~1323 s. This makes the X-ray pulsar with the longest period known in the Small Magellanic Cloud (SMC). More than 150 X-ray observations of by ROSAT, Chandra and XMM-Newton show flux variations by a factor of 50 on time scales of days to years. U…
Thermal evolution model of 67P/Churyumov-Gerasimenko, the new Rosetta target
Coradini, A.; Capria, M. T.; de Sanctis, M. C.
Rosetta, the ESA mission dedicated to the detailed study of a comet nucleus before and after the onset of activity, will arrive at comet 67P/Churyumov-Gerasimenko in 2014. At the moment, little is known about this comet, but the successful design of the ROSETTA mission requires some preliminary knowledge of the comet physical parameters. These qua…
Velocity field and star formation in the Horsehead nebula
Teyssier, D.; Güsten, R.; Hily-Blant, P. +1 more
Using large scale maps in C18O(2-1) and in the continuum at 1.2 mm obtained at the IRAM-30 m antenna with the Heterodyne Receiver Array (HERA) and MAMBO2, we investigated the morphology and the velocity field probed in the inner layers of the Horsehead nebula. The data reveal a non-self-gravitating (m/m_vir≈ 0.3) filament of dust and ga…
XMM-Newton spectroscopy of an X-ray selected sample of RL AGNs
Page, M. J.; Braito, V.; Caccianiga, A. +6 more
This paper presents the X-ray spectroscopy of an X-ray selected sample of 25 radio-loud (RL) AGNs extracted from the XMM-Newton Bright Serendipitous Survey (XBSS). The main goal of the work is to assess and study the origin of the X-ray spectral differences usually observed between radio-loud and radio-quiet (RQ) AGNs. To this end, a comparison sa…
Using the ROSAT Bright Source Catalogue to find counterparts for IBIS/ISGRI survey sources
Walter, R.; Bird, A. J.; Ubertini, P. +8 more
The IBIS/ISGRI first year galactic plane survey has produced a catalogue containing 123 hard X-ray sources visible down to a flux limit of a few milliCrabs. The point source location accuracy of typically 1-3 arcmin has allowed the counterparts for 95 of these sources to be found at other wavelengths. In order to identify the remaining 28 objects,…
3D continuum radiative transfer in complex dust configurations. II. 3D structure of the dense molecular cloud core ρ Oph D
Henning, Th.; Bacmann, A.; Stickel, M. +2 more
Constraints on the density and thermal 3D structure of the dense molecular cloud core ρ Oph D are derived from a detailed 3D radiative transfer modeling. Two ISOCAM images at 7 and 15 µm are fitted simultaneously by representing the dust distribution in the core with a series of 3D Gaussian density profiles. Size, total density and position …
Mid-IR observations of circumstellar disks. I. Pre-main sequence objects
Sterzik, M. F.; Meeus, G.; Schütz, O.
We present new N-band photometry and spectroscopy for a sample of eight pre-main sequence stars including T Tauri, Herbig Ae/Be stars and FU Ori objects using the ESO TIMMI2 camera at the La Silla observatory (Chile). For some objects this is their first N-band spectroscopic observation ever. The FU Ori stars V 346 Nor, V 883 Ori and Z CMa show a …
Extreme helium stars: non-LTE matters. Helium and hydrogen spectra of the unique objects V652 Her and HD 144941
Butler, K.; Heber, U.; Przybilla, N. +1 more
Quantitative analyses of low-mass hydrogen-deficient (super-)giant stars - so-called extreme helium stars - to date face two major difficulties. First, theory fails to reproduce the observed helium lines in their entirety, wings and line cores. Second, a general mismatch exists for effective temperatures derived from ionization equilibria and from…
W Hya through the eye of Odin. Satellite observations of circumstellar submillimetre H2O line emission
Olofsson, H.; Justtanont, K.; Larsson, B. +10 more
We present Odin observations of the AGB star W Hya in the ground-state transition of ortho-H{2}O, 1{10}-101, at 557 GHz. The line is clearly of circumstellar origin. Radiative transfer modelling of the water lines observed by Odin and ISO results in a mass-loss rate of (2.5±0.5)×10-7 M⊙ yr-1, and a circu…
To see or not to see a bow shock. Identifying bow shocks with Hα allsky surveys
Brown, D.; Bomans, D. J.
OB-stars have the highest luminosities and strongest stellar winds of all stars, which enables them to interact strongly with their surrounding ISM, thus creating bow shocks. These offer us an ideal opportunity to learn more about the ISM. They were first detected and analysed around runaway OB-stars using the IRAS allsky survey by van Buren et al…