Search Publications
Observational evidence of the primary role played by photospheric motions in magnetic helicity transport before a filament eruption
Romano, P.; Contarino, L.; Zuccarello, F.
Many filament eruptions can be suitably described in the framework of the kink instability model, although it is not always easy to discriminate whether the helical flux rope writhes due to new emerging flux or to photospheric horizontal motions. In this paper we provide observational evidence of the important role which can be played by horizonta…
Flows in the solar atmosphere due to the eruptions on the 15th July, 2002
Mandrini, C. H.; van Driel-Gesztelyi, L.; Culhane, J. L. +4 more
Which kind of flows are present during flares? Are they compatible with the present understanding of energy release and which model best describes the observations? We analyze successive flare events in order to answer these questions. The flares were observed in the magnetically complex NOAA active region (AR) 10030 on 15 July 2002. One of them i…
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…