We report the discovery of two counterrotating stellar disks in the early-type spiral galaxy NGC 3593. The major axis kinematics shows the presence of two dynamically cold counterrotating components. The surface brightness profile is well reproduced by the sum of the contributions of two exponential disks of different scale lengths (r_1 = 40″; r_2 = 10″) and different central surface brightnesses (μ_(r,1) = 19.9; μ_(r,2) = 18.5 mag arcsec~(-2)). The v and σ radial profiles are easily reproduced by the means of a kinematical model adopting the above photometric parameters. An ionized gas disk is present. It corotates with the smaller scale length and less massive (M_2 = 2.7 X 10~9 solar mass) disk, and counterrotates with the larger and more massive (M_1 = 1.2 X 10~(10) solar mass) one. We conclude that the smaller stellar disk is the result of a slow adiabatic acquisition of a conspicuous amount of counterrotating gas (M_(infall) ～ 4.3 X 10~9 solar mass) by the preexisting galaxy, originally constituted mainly by a gas-free stellar disk (disk 1). The counterrotating gas settled into the equatorial plane and then formed the inner stellar disk (disk 2).
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机译：我们报告了在早期类型的旋涡星系NGC 3593中发现了两个反向旋转的恒星盘。主轴运动学表明存在两个动态的冷反向旋转组件。通过两个不同刻度长度（r_1 = 40“; r_2 = 10”）和不同中心表面亮度（μ_（r，1）= 19.9;μ_（r ，2）= 18.5 mag arcsec〜（-2））。通过采用上述光度学参数的运动学模型，可以轻松再现v和σ径向轮廓。存在离子化气体盘。它与较小的标度长度和较小的质量（M_2 = 2.7 X 10〜9太阳质量）圆盘一起旋转，而与较大且质量较大的（M_1 = 1.2 X 10〜（10）太阳质量）圆盘一起旋转。我们得出结论，较小的恒星盘是由先前主要由无气体恒星构成的先前存在的星系缓慢绝热获取大量反向旋转气体（M_（infall）〜4.3 X 10〜9太阳质量）的结果。磁盘（磁盘1）。反向旋转的气体沉降到赤道平面，然后形成内部恒星盘（盘2）。
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