We propose to observe either a new or a known black-hole transient for 680 ks (about 4 INTEGRAL orbits) when thesource is showing a bright hard state (above 200 mCrab). Our main goals are: to detect the soft gamma-ray tail observed in the spectra above 200 keV (mainly with SPI), to measure a SED from radio to gamma-rays using the multi-wavelength observations that we will trigger, to follow the high-energy cutoff variation of hard X-ray spectral component (mainly with IBIS). The above will allow us to improve our understanding of the accretion-ejection connection in black-hole transients. The INTEGRAL TAC approved this proposal for the last AO19. However, the observations have been not triggered yet, due to the lack of a suitable target.
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, Del Santo, 2025, 'Focussing onto the gamma-ray emission of Black Hole Transients in the bright hard state', 1.0, European Space Agency, https://doi.org/10.57780/esa-pwrehx2
