We present slitless spectra of the narrow-line region (NLR) in NGC 4151 from the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope and investigate the kinematics and physical conditions of the emission-line clouds in this region. Using medium resolution (~0.5 ?) slitless spectra at two roll angles and narrow-band undispersed images, we have mapped the NLR velocity field from 1.2 kpc to within 13 pc (H0 = 75 km s-1 Mpc-1) of the nucleus. The inner biconical cloud distribution exhibits recessional velocities relative to the nucleus to the NE and approaching velocities to the SW of the nucleus. We find evidence for at least two kinematic components in the NLR. One kinematic component is characterized by low velocities and low velocity dispersions (LVLVD clouds: v 400 km s-1, and Δv 130 km s-1). This population extends through the NLR, and their observed kinematics may be gravitationally associated with the host galaxy. Another component is characterized by high velocities and high velocity dispersions (HVHVD clouds: 400 v 1700 km s-1, Δv ≥ 130 km s-1). This set of clouds is located within 11 (~70 pc) of the nucleus and has radial velocities that are too high to be gravitational in origin but show no strong correlation between velocity or velocity dispersion and the position of the radio knots. Outflow scenarios will be discussed as the driving mechanism for these HVHVD clouds. We also find clouds characterized by low velocities and high velocity dispersions (LVHVD clouds: v 400 km s-1, Δv ≥ 130 km s-1). These clouds are located within 32 (~200 pc) of the nucleus. It is not clear if the LVHVD clouds are HVHVD clouds whose low velocities are the result of projection effects. Within 32 (~200 pc) of the nucleus, the [O III]/Hβ ratio declines roughly linearly for both the high-velocity-dispersion (HVD) and LVLVD clouds. Since the ionization parameter is proportional to r-2n-1, it appears that the density, n, must decrease as ~r-1 for the clouds within the inner ~32. At distances further from the nucleus, the [O III]/Hβ ratio is roughly constant.
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机译：我们从哈勃太空望远镜上的太空望远镜成像光谱仪（STIS）提出了NGC 4151中窄线区域（NLR）的无缝谱，并研究了该区域中发射线云的运动学和物理条件。使用两个滚动角的中分辨率（〜0.5？）无缝光谱和窄带未分散图像，我们将NLR速度场从1.2 kpc映射到原子核的13 pc（H0 = 75 km s-1 Mpc-1）内。内双锥云分布相对于NE相对于原子核具有凹陷速度，而相对于SN则具有接近速度。我们找到了NLR中至少两个运动学成分的证据。一种运动学特征是低速度和低速度色散（LVLVD云：v <400 km s-1，Δv<130 km s-1）。该种群遍及NLR，其观测到的运动学可能在重力上与宿主星系相关。另一个成分的特征是速度快和速度快（HVHVD云：400 展开▼
