SAUNAS. II. Discovery of Cross-shaped X-Ray Emission and a Rotating Circumnuclear Disk in the Supermassive S0 Galaxy NGC 5084

Abstract

Combining Chandra, Atacama Large Millimeter/submillimeter Array, EVLA, and Hubble Space Telescope archival data and newly acquired data from the Apache Point Observatory/Dual Imaging Spectrograph, we detect a double-lobed 17 kpc X-ray emission with plumes oriented approximately perpendicular and parallel to the galactic plane of the massive lenticular galaxy NGC 5084 at 0.3–2.0 keV. We detect a highly inclined ( i = 71.2 − 1.7 + 1.8 ◦ ), molecular circumnuclear disk ( D = 304 − 11 + 10 pc) in the core of the galaxy rotating (V rot ( 2 − 1 ) CO = 242.7 − 6.4 + 9.6 km s−1) in a direction perpendicular to that of the galactic disk, implying a total mass of log 10 M BH M ⊙ = 7.66 − 0.15 + 0.21 for NGC 5084's supermassive black hole. Archival EVLA radio observations at 6 and 20 cm reveal two symmetric radio lobes aligned with the galactic plane, extending to a distance of R ¯ = 4.6 ± 0.6 kpc from the core, oriented with the polar axis of the circumnuclear disk. The spectral energy distribution lacks strong emission lines in the optical range. Three formation scenarios are considered to explain these multiwavelength archival observations: (1) active galactic nuclei (AGN) reorientation caused by accretion of surrounding material, (2) AGN-driven hot gas outflow directed along the galactic minor axis, or (3) a starburst/supernovae driven outflow at the core of the galaxy. This discovery is enabled by new imaging analysis tools including the Selective Amplification of Ultra Noisy Astronomical Signal, demonstrating the abundance of information still to be exploited in the vast and growing astronomical archives.