M87 at 90 Centimeters: A Different Picture

摘要

We report new radio imaging of the large-scale radio structure of M87 with the VLA at 90 cm. These new images show the complex structure of the radio emission more clearly than previous attempts, some of which date back to the 1940s. The images suggest that the outward flow from the M87 nucleus extends well beyond the 2 kpc jet. Two 'bubbles' of synchrotron emission appear to be inflated by this flow. A simple model of the emission, combined with our knowledge of the inner jet, suggest that the energy input into this region from the M87 nucleus exceeds the energy being radiated away as X-rays. This argues that the region within 40 kpc of the center of M87 is currently dominated by energy input from the M87 nucleus. The gas in the region is expanding, not owing inward as is envisioned in the cooling flow model.