Filaments, Bubbles, and Weak Shocks in the Gaseous Atmosphere of M87

We present the first results from a 500 ksec Chandra ACIS-I observation ofM87. At soft energies (0.5-1.0 keV), we detect filamentary structuresassociated with the eastern and southwestern X-ray and radio arms. Manyfilaments are spatially resolved with widths of ~300 pc. This filamentarystructure is particularly striking in the eastern arm where we suggest thefilaments are outer edges of a series of plasma-filled, buoyant bubbles whoseages differ by ~6 x 10^6 years. These X-ray structures may be influenced bymagnetic filamentation. At hard energies (3.5-7.5 keV), we detect a nearlycircular ring of outer radius 2.8' (13 kpc) which provides an unambiguoussignature of a weak shock, driven by an outburst from the SMBH. The densityrise in the shock is ~1.3 (Mach number, M~1.2). The observed spectral hardeningin the ring corresponds to a temperature rise T_shock / T_0 ~ 1.2, or M~1.2, inagreement with the Mach number derived independently from the gas density.Thus, for the first time, we detect gas temperature and density jumpsassociated with a classical shock in the atmosphere around a supermassive blackhole. We also detect two additional surface brightness edges and pressureenhancements at radii of ~0.6' and ~1'. The ~0.6' feature may beover-pressurized thermal gas surrounding the relativistic plasma in the radiococoon, the ``piston'', produced by the current episode of AGN activity. Theover-pressurized gas is surrounded by a cool gas shell. The ~1' feature may bean additional weak shock from a secondary outburst. In an earlier episode, the``piston'' was responsible for driving the 2.8' shock.Comment: Extensively revised and expanded with 10 pages and 10 figures. Accepted for publication in the Astrophysical Journa