Search Publications
Magnetic field measurements and wind-line variability of OB-type stars
Rygl, K. L. J.; Neiner, C.; Wiersema, K. +8 more
Context: The first magnetic fields in O- and B-type stars that do not belong to the Bp-star class, have been discovered. The cyclic UV wind-line variability, which has been observed in a significant fraction of early-type stars, is likely to be related to such magnetic fields.
Aims: We attempt to improve our understanding of massive-star magne…
The secrets of T Pyxidis. II. A recurrent nova that will not become a SN Ia
Selvelli, P.; González-Riestra, R.; Gilmozzi, R. +1 more
Aims: We compare the observed and theoretical parameters for the quiescent and outburst phases of the recurring nova T Pyx.
Methods: IUE data were used to derive the disk luminosity and the mass accretion rate, and to exclude the presence of quasi-steady burning at the WD surface. XMM-NEWTON data were used to verify this conclusion.
Result…
New XMM-Newton observations of supernova remnants in the Small Magellanic Cloud
Pietsch, W.; Haberl, F.; Filipović, M. D. +6 more
Context: A complete overview of the supernova remnant (SNR) population is required to investigate their evolution and interaction with the surrounding interstellar medium in the Small Magellanic Cloud (SMC).
Aims: Recent XMM-Newton observations of the SMC cover three known SNRs (DEM S5, SNR B0050-72.8, and SNR B0058-71.8), which are poorly stu…
Observations of Hα surges and ultraviolet jets above satellite sunspots
Jiang, Y. C.; Chen, H. D.; Ma, S. L.
Aims:To know more about the physical origin of surges and jets, we investigated seven successive surge events, which occurred above the satellite sunspots of active region NOAA 10720 on 2005 January 15.
Methods: Using data from the Transition Region and Coronal Explorer (TRACE), Big Bear Solar Observatory (BBSO) and Solar and Heliospheric Obse…
INTEGRAL discovery of non-thermal hard X-ray emission from the Ophiuchus cluster
Paltani, S.; Eckert, D.; Produit, N. +2 more
We present the results of deep observations of the Ophiuchus cluster of galaxies with INTEGRAL in the 3-80 keV band. We analyse 3 Ms of INTEGRAL data on the Ophiuchus cluster with the IBIS/ISGRI hard X-ray imager and the JEM-X X-ray monitor. In the X-ray band using JEM-X, we show that the source is extended, and that the morphology is compatible w…
INTEGRAL observations of the blazar Mrk 421 in outburst. Results of a multi-wavelength campaign
Lähteenmäki, A.; Ajello, M.; Horan, D. +15 more
Context: If one wants to understand the physics of blazars, better simultaneous observations are important at all wavelengths, so it was fortunate that a ToO observation of the TeV-emitting blazar Mrk 421 with INTEGRAL could be triggered in June 2006 by an increase in the RXTE count rate to more than 30 mCrab. The source was then observed with all…
Giant outburst of EXO 2030+375: pulse-phase resolved analysis of INTEGRAL data
Klochkov, D.; Santangelo, A.; Ferrigno, C. +1 more
In June-September 2006 the Be/X-ray binary EXO 2030+375 experienced the second giant outburst since its discovery. The source was shown to have a complicated pulse-averaged X-ray spectral continuum with possible evidence of cyclotron absorption features. In this paper we present the first pulse-phase resolved analysis of the broad band X-ray spect…
Molecular jets driven by high-mass protostars: a detailed study of the IRAS 20126+4104 jet
Eislöffel, J.; Nisini, B.; Giannini, T. +2 more
Context: Protostellar jets from intermediate- and high-mass protostars provide an excellent opportunity to understand the mechanisms responsible for intermediate- and high-mass star-formation. A crucial question is if they are scaled-up versions of their low-mass counterparts. Such high-mass jets are relatively rare and, usually, they are distant …
Absorption features in the spectra of X-ray bursting neutron stars
Rauch, T.; Werner, K.; Suleimanov, V.
Context: The discovery of photospheric absorption lines in XMM-Newton spectra of the X-ray bursting neutron star in
Mg II h+k emission lines as stellar activity indicators of main sequence F-K stars
Buccino, A. P.; Mauas, P. J. D.
Context: The largest dataset of stellar activity measurements available at present is the one obtained at the Mount Wilson Observatory, where high-precision Ca II H+K fluxes have been measured from 1966 for about 2200 stars. Since the Mg II h and k lines at λ2800 Å are formed in a similar way to the Ca II H+K emission lines, they are also good ind…