Black hole X-ray binaries (BHXBs) cycle through different accretion states rapidly, providing a time- resolved view of how matter behaves in a strong gravity environment. Simultaneous multi-wavelength observations are the optimal tool that exposes this view. However, these campaigns (connecting the evolving accretion inflow and jet outflow) have been rarely achieved. We request a TOO consisting of two INTEGRAL revolutions (340ks) of a BHXB as it transitions from the hard to the soft state to complement our Astrosat accepted coverage. Our target list contains 15 candidates. We target the transition to reveal both the rapid orbit-to-orbit X-ray variability and the slower X-ray variability that characterize the significantly changing accretion disk (derived from X-ray spectra and timing), and directly measure the broad-band SED in connection with multi-wavelength coverage. The INTEGRAL data will be crucial to extend the coverage at high energies and obtain complete spectral information.
Publications
Hard X-rays and QPO in Swift J1727.8-1613: the rise and plateau of the 2023 outburst - Mereminskiy, I., Lutovinov, A.,Molkov, S.,Krivonos, R.,Semena, A.,Sazonov, S.,Tkachenko, A.,Sunyaev, R. (2024-07-01) http://ui.adsabs.harvard.edu/#abs/2024MNRAS.531.4893M
INTEGRAL/IBIS polarization detection in the hard and soft intermediate states of Swift J1727.8-1613 - Bouchet, T., Rodriguez, J.,Cangemi, F.,Thalhammer, P.,Laurent, P.,Grinberg, V.,Wilms, J.,Pottschmidt, K. (2024-08-01) http://ui.adsabs.harvard.edu/#abs/2024A&A...688L...5B
The INTEGRAL (International Gamma-Ray Astrophysics Laboratory) mission, launched by the European Space Agency (ESA) on October 17, 2002, was designed to study high-energy phenomena in the universe. INTEGRAL was operating until february 2025 and it was equipped with three high-energy instruments: the Imager on Board the INTEGRAL Satellite (IBIS), the Spectrometer on INTEGRAL (SPI), and the JEM-X (Joint European Monitor for X-rays). Its Optical Monitoring Camera (OMC) provided optical V-band magnitude measurements, complementing the high-energy observations.
European Space Agency, Motta, 2025, 'A multi-wavelength campaign to observe a bright black hole transient in transition', 1.0, European Space Agency, https://doi.org/10.57780/esa-0xc6o6f
