Synergistic ALMA and X-ray Views of AGN Structures from the Corona to the Torus and Beyond

Active galactic nuclei (AGNs) are not only key laboratories for understanding supermassive black hole (SMBH) accretion, but also essential for exploring the co-evolution of SMBHs and their host galaxies. AGNs are believed to harbor a central SMBH surrounded by a hot corona, an accretion disk, and a surrounding obscuring structure known as the torus. Utilizing ALMA and various X-ray observatories, including the high-spectral-resolution mission of XRISM, we have been conducting a series of studies to investigate AGN structures from the corona, through the torus, and beyond. Our analyses include the largest systematic continuum survey in the millimeter and X-ray bands, which provides insights into the formation and heating mechanisms of the AGN corona. Furthermore, by combining ALMA observations of molecular gas emission lines with X-ray mapping of the fluorescent Fe Kalpha line, we have assessed the impact of AGN X-ray radiation on the molecular gas on scales of a few hundreds of parsecs. This result offers a new insight into AGN feedback on the circumnuclear interstellar medium. Now, with the advent of XRISM, we spectrally reveal gas motion from the innermost accretion flow to the torus region. Comparison with ALMA observations is capable of unveiling the multi-layered AGN structure. In this presentation, we will highlight how the synergy between ALMA and X-ray observations is significant to advance our understanding of AGN structures.