00311nas a2200121   4500000000100000000000100001008004100002100002000043700001200063245009700075300000900172490000800181       2009                            d1 aA. E. Broderick1 aA. Loeb00aImaging the Black Hole Silhouette of M87: Implications for Jet Formation and Black Hole Spin  a11640 v697