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Spectral behaviour of an INTEGRAL sample of black hole candidates: Initial results
Capitanio, F.; Bazzano, A.; Cadolle Bel, M. +13 more
In this paper, we present the spectral characteristics of a sample of Black Hole Candidates observed with the IBIS, SPI and JEM-X instruments on board the INTEGRAL Gamma-ray Observatory. This work is part of the long term, systematic, spectral study programme of intermediate intensity BHC (<500 mCrab) within the INTEGRAL Core Programme observat…
Unveiling hidden AGN by IR observations
Haas, Martin
AGN can be dust-hidden by two ways and this talk considers how to unveil them in the infrared: firstly, the powerful 3CR radio galaxies, i.e., type-2 AGN which suffer from anisotropic obscuration of the nuclear region by the dust torus, and secondly, type-1 quasars, which seem to be isotropically reddened by dust, so that they escape detection via…
X-ray emission from PTT stars
Mason, H. E.; Bromage, G. E.; Landini, M. +4 more
We present preliminary results on an XMM-Newton observation dedicated to Post-T-Tauri (PTT) stars. We observed the visual binary 2RE J0241-53 of the Horologium association of nearby PTT stars. The XMM observations have been complemented with ground-based optical spectroscopy and photometry. Several flares have been observed. The X-ray spectrum of …
A highly-ionized absorber as a new explanation for the spectral changes during dips from X-ray binaries
Kaastra, J. S.; Díaz Trigo, M.; Parmar, A. N. +2 more
We report the XMM-Newton detection of narrow Fe XXV and Fe XXVI X-ray absorption lines at 7 keV in the persistent emission of the dipping low-mass X-ray binary (LMXB) 4U 1323-62. Such features have now been reported in a growing number of LMXBs seen almost edge-on, indicating that the highly-ionized plasma probably originates in an accretion disk …
Effects of the photo-ionized absorber on the continuum spectra of EXO 0748 676
Asai, Kazumi; Dotani, Tadayasu
We report on the analysis of XMM-Newton archival data of EXO 0748-676. We studied changes of the continuum spectra due to the presence of photo-ionized plasma on the line of sight. We show that the ionization degree of the plasma could change largely during the X-ray bursts and the dips. These changes can significantly modify the soft-band spectru…
Microquasars: What do radio and X-ray observations tell us?
Wu, Kinwah; Rodriguez, Jérôme; Vilhu, Osmi +4 more
Microquasars, or X-ray binaries exhibiting radio jets, have been observed extensively at all wavelengths for the past decade or so. Primarily, they have been observed in the X-ray regimes and the radio. In this paper we review the radio and the X-ray behavior of the first two superluminal microquasars, GRS 1915+105 and GRO J1655-40. We show how GR…
Pulsation Modes and Fundamental Parameters of Mira Stars
Barthes, D.
Linear pulsation models are generated using the absolute magnitudes of long period variables (LPVs) in the Large Magellanic Cloud (LMC) and in the solar neighborhood (HIPPARCOS parallaxes), as well as effective temperature estimates. The results support the hypothesis that linear modeling may be used provided that a lower mixing length (possibly e…
Discovery of ADC absorption in the LMXB XB 1323-619 with XMM-Newton
Church, M. J.; Reed, D.; Dotani, T. +2 more
In our observation of the LMXB XB 1323-619 made with XMM-Newton in January 2003, a number of absorption lines were discovered, notably at 6.70 and 6.98 keV which we identify with scattering by high ionization state ions Fe XXV and Fe XXVI. Curve of growth analysis provided a consistent solution for collisional ionization for a plasma temperature k…
Flare diagnostics from loop modeling of a stellar flare observed with XMM-Newton
Reale, Fabio
XMM-Newton data of an X-ray flare observed on Proxima Centauri provide detailed and challenging constraints for flare modeling. The comparison of the data with the results of time-dependent hydrodynamic loop modeling of this flare allows us to constrain not only the loop morphology, but also the details of the heating function. The results show th…
INTEGRAL observation of the Crab pulsar
Cusumano, G.; Foschini, L.; Di Cocco, G. +5 more
In this paper, we present the timing and spectral analysis of several observations of the Crab pulsar with INTEGRAL. All these observations, when summed together provide an high-statistics data set which can be used for accurate phase resolved spectroscopy of the pulsed emission over the energy range 3 350 keV. In particular, we present the light …