Radial Structure and Spectral Stratification in Sagittarius A and M87: A Comparative X-ray Analysis

This project presents the first systematic comparison of the radial X-ray emission structure between Sagittarius A* (Sgr A*) and Messier 87 (M87), two supermassive black holes differing in mass by a factor of ~1500. Using high-resolution, multi-energy Chandra X-ray Observatory data, we analyze images in three distinct energy bands (0.2–3.3 keV, 3.3–4.7 keV, and 4.7–8.0 keV) to characterize morphological and spectral features. Through radial profile analysis, difference imaging, and energy-dependent morphology mapping, we identify pronounced radial structure and spectral hardening in Sgr A*, and similar central concentration patterns in M87. These results indicate structural consistency in accretion flow geometry despite large differences in mass, luminosity, and surrounding environment. Our findings provide constraints on accretion physics, spectral stratification, and energy-dependent morphology in low-luminosity active galactic nuclei (LLAGN), establishing a baseline for comparative studies across the black hole mass spectrum.