We ask for two INTEGRAL ToO observations of 600 ks each coordinated with the Imaging X-ray PolarimetryExplorer (IXPE),a recently launched NASA mission devoted to X-ray polarimetry. The aim of this proposal is to studyin detail the geometry and the inclination of the transient black hole low mass X-ray binaries (BH-LMXB). The IXPEobservation plan foresees for the second year of operations 5 ToOs devoted to continue the study of transient blackhole X-ray binary target. The combined IXPE/INTEGRAL observations, in this case, will be a unique opportunityto provide a broad-band X-ray spectroscopy and a simultaneous measure of the X-ray polarization. This will resultin an unprecedented view of the system geometry and the role of jets and corona in X-ray binaries. This proposalhas already been accepted in AO18 and AO19. However, until the date of the submission of this proposal, there wereno LMXB outbursts suitable for IXPE observations.
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, Capitanio, 2025, 'Study of the corona geometry and system inclinaton in BH LMXB. A coordinated IXPE/INTEGRAL ToO observation', 1.0, European Space Agency, https://doi.org/10.57780/esa-ieajolf
