Tell-Tale Spectral Signatures of MHD Disk-Winds at All Mass Scales with Microcalorimeter Spectroscopy

Despite our phenomenological understanding of X-ray disk-winds detected across black hole mass scales (i.e. AGNs and XRBs) owing to an intensive observational effort over the past decades, the underlying physical identity of disk-winds (e.g. location, geometry and driving mechanisms) is yet to be known. In this work we argue that it is plausible to realistically differentiate the leading launching processes (thermal, radiation and magnetic) with high S/N non-dispersive data such as microcalorimeter spectroscopy. In the context of MHD wind scenario, we show that MHD-driven winds are likely to imprint “on average” an extended blue tail of unique asymmetry in absorption line profiles. Such a characteristic line signature, being almost generic to MHD disk winds due to the intrinsic wind kinematics and absorption measure distribution (AMD), can be utilized as a diagnostic proxy independent of black hole mass. This tangible “magnetic sign” is also robustly immune to the contamination due to other spectral components such as non-magnetic absorbers and reflection features. We demonstrate a high fidelity of microcalorimeter observations in anticipation of the upcoming XRISM/Resolve data by performing spectral simulations. This diagnosis can in principle provide a long-awaited “smoking gun” to ultimately help settle the outstanding question in ionized disk-winds across different mass scales.