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تسجيل مستخدم جديدFlux and spectral variations of 1E${thinspace}$1740.7$-$2942 over the years 2003$-$2012
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The black hole system 1E${thinspace}$1740.7$-$2942 is usually the brightest hard X-ray source (above 20 keV) near the Galactic Center, but presents some epochs of low emission (below the INTEGRAL detection limit, for example). In this work, we present the results of studies on 1E${thinspace}$1740.7$-$2942 over 10 years, using the instruments ISGRI/IBIS and JEM-X, both on board the INTEGRAL observatory. We fit the spectra with both the compTT and cutoffpl models. According to the fits and taking the mean value over the 10 years, we have obtained a plasma temperature in the range $sim$20$,-,$90$thinspace$ keV, and an average powerlaw index of 1.41 ($sigma$=0.25). We have also made a Lomb$,-,$Scargle periodogram of the flux in the 50$,-,$20${thinspace}$keV band and found two tentative periods at 2.90 and 3.99${thinspace}$days. We present here the preliminary results of this ongoing work.
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We present results of the monitoring of the black hole candidate 1E 1740.7-2942 with INTEGRAL, in combination with simultaneous observations by RXTE. We concentrate on broad-band spectra from INTEGRAL/IBIS and RXTE/PCA instruments. During our observa
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Studies of the long-term spectral variations have been used to constrain the emission processes of black hole candidates. However, a common scenario which is able to explain the emission from soft to hard X-rays has been proposed only recently. Here,
we use XMM and INTEGRAL data on 1E 1740.7-2942 in order to demonstrate that Comptonization plays an important role in producing high energy photons, as predicted by the current modeling scenario.
The microquasar 1E 1740.7-2942 is one of the most appealing source of the Galactic Centre region. The high energy feature detected once by SIGMA has been searched in the last years by INTEGRAL, but never confirmed. Classified as a persistent source,
on 2004 it showed a quiescent-like state. In fact for few month 1E 1740.7-2942 was below the detector sensitivity level. We present the long term temporal behaviour of 1E 1740.7-2942 observed by INTEGRAL and RXTE in 2004 and 2005, as well as preliminary results on possible spectral transitions.
The brightest persistent Galactic black hole candidate close to the Galactic Centre, 1E 1740.7-2942, has long been observed with INTEGRAL. In this paper, we report on the long-term hard X-ray monitoring obtained during the first year of observations
as part of the Galactic Centre Deep Exposure. We discuss the temporal and spectral behaviours in different energy bands up to 250 keV, as well as the hardness-flux correlations.
The microquasar 1E 1740.7-2942 is observed with Integral since Spring 2003. Here, we report on the source high energy behaviour by using the first three years of data collected with SPI and IBIS telescopes, taking advantage of the instruments complem
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