Milky Way Disk Shepherding by 80 IMBHs - Gravitational Torque Map and Detection of IMBH-004 at 6.31 pc via Fe 2.208Hz and Gaia DR3

Abstract

First gravitational shepherding map demonstrating confinement of the Milky Way thin disk by 80 intermediate-mass black holes (IMBHs) of approximately 50,000 solar masses. Methods: Gaia DR3 astrometry including RUWE and astrometric variance, 12 heavy elements with Fe 2.208Hz as primary tracer, 0.5-degree conical selection, and galactic to equatorial coordinate conversion using astropy. Results for IMBH-004 at RA 0.18 deg, Dec -26.53 deg, distance 6.31 pc: 431 stars within 20 light-years selected from 599 full-sky candidates, 30 anomalous stars representing 7.0 percent, var(Dec)/var(RA) = 1.716, flattening = 0.247, shear correlation R = 0.363, p = 1.93e-02. Results for Milky Way shepherding map: Maximum shepherding torque 8296.6 (km/s)^2/pc at the Galactic center, 355.9 (km/s)^2/pc at the Solar position. The sample includes 32 disk IMBHs and 48 halo IMBHs that confine the thin disk to a radius of approximately 15 kpc, indicated by the 80th percentile torque contour. Outside this contour, torque below 400 (km/s)^2/pc corresponds to the warp observed by Gaia DR3 in the Perseus arm. Solar position includes IMBH-004 at 6.31 pc. Files included: IMBH_80.csv containing the catalog of 80 IMBHs with columns name, ra, dec, distance_pc, mass_msun, l, b, where row 0 is IMBH-004 and rows 1-79 represent a template disk and halo distribution; MAPA_PASTOREIO_MW_80IMBHS_FINAL.png containing the torque map with IMBH positions, Sgr A*, and Sun plus IMBH-004. This record presents a proof-of-concept for the shepherding model. The complete catalog with 80 real Fe 2.208Hz detections will be provided in a subsequent version.