Long term monitoring of the BHC 1E 1740.7-2942

TL;DR

This paper presents a long-term observational study of the microquasar 1E 1740.7-2942, analyzing its temporal behavior and spectral states over two years using INTEGRAL and RXTE data.

Contribution

It provides the first detailed long-term monitoring of 1E 1740.7-2942, including detection of quiescent states and potential spectral transitions.

Findings

Detected quiescent-like state in 2004

Observed possible spectral transitions

Analyzed long-term temporal behavior

Abstract

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.