A variable magnetic disc wind in the black hole X-ray binary GRS 1915+105?

Context. GRS 1915+105 being one of the brightest transient black hole binaries (BHBs) in X-rays offers a unique testbed for study connection between accretion and ejection mechanisms BHBs. In particular, this source can be used to disc wind its dependence on state changes Aims. Our aim is investigate origin geometry 1915+105. This will provide basis planning future observations with X-ray Imaging Spectroscopy Mission (XRISM), may also important parameters estimating polarimetric signal upcoming Polarimetry Explorer (IXPE). Methods. We analysed spectra soft ϕ hard χ classes using high-resolution spectroscopy offered by Chandra HETGS. state, we find series absorption lines that follow non-linear velocity width, shift, equivalent width respect ionisation, indicating multiple component or stratified outflow. only faint Fe XXVI line. model both states dedicated magneto-hydrodynamic (MHD) magnetic probe cause variability observed line flux two states. Conclusions. The MHD provides good fit states, possibility wind. ionisation components are well characterised as stratification same cannot explained photo-ionisation alone but most likely due large (three orders magnitude) increase density. mass outflow rate comparable rate, suggesting an intimate link processes lead