DYNAMICAL EVOLUTION OF AGN HOST GALAXIES—GAS IN/OUT-FLOW RATES IN SEVEN NUGA GALAXIES
DYNAMICAL EVOLUTION OF AGN HOST GALAXIES—GAS IN/OUT-FLOW RATES IN SEVEN NUGA GALAXIES
复制标题
DOI：
10.1088/0004-637x/692/2/1623
复制
发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
S. Haan;E. Schinnerer;E. Emsellem;S. García-Burillo;F. Combes;C. Mundell;H. Rix
中科院分区：
文献类型：
--
作者：
S. Haan;E. Schinnerer;E. Emsellem;S. García-Burillo;F. Combes;C. Mundell;H. Rix
为了检查宿主星系结构在为核活动提供燃料中的作用，我们估计了从星系核样本中选出的七个附近螺旋星系的气体流速，从几 kpc 到内部的几十 pc。我们根据分子（使用 Plateau de Bure 干涉仪的 CO）和原子（使用甚大阵列的 H i）气体的高角分辨率干涉观测，从近红外图像计算了引力矩，并确定了气体流入/流出流速作为半径和银河盘内位置的函数。将结果与从几种不同方法得出的径向气流和星系动力学状态（通过共振）的运动学证据进行比较。我们证明，引力扭矩非常有效地将气体从外盘一直输送到约 100 pc 的星系中心；先前假设的气体传输动力障碍，例如恒星棒的共转共振，似乎可以通过来自其他非轴对称结构的重力扭矩引起的气流来克服。由此产生的气体质量流入速率范围为 0.01 至 50 M☉ yr−1，并且星系中心的气体质量流入速率大于外盘的气体质量流入速率。我们的气体流量图显示了三个星系的较大条形中嵌套条形的作用。运动学图中发现的非圆形流运动在中心比在外盘大，并且似乎与作为半径函数的流入/流出速率松散相关。我们证明，螺旋气盘是非常动态的系统，由于引力扭矩在重新分配冷星系气体方面的有效性，它在几个自转周期的时间尺度上（例如，5×108年，半径为5 kpc）经历强烈的径向演化。
To examine the role of the host galaxy structure in fueling nuclear activity, we estimated gas flow rates from several kpc down to the inner few 10 pc for seven nearby spiral galaxies, selected from the NUclei of GAlaxies sample. We calculated gravitational torques from near-infrared images and determined gas in/out-flow rates as a function of radius and location within the galactic disks, based on high angular resolution interferometric observations of molecular (CO using Plateau de Bure interferometer) and atomic (H i using the Very Large Array) gas. The results are compared with kinematic evidence for radial gas flows and the dynamical state of the galaxies (via resonances) derived from several different methods. We show that gravitational torques are very efficient at transporting gas from the outer disk all the way into the galaxies centers at ∼100 pc; previously assumed dynamical barriers to gas transport, such as the corotation resonance of stellar bars, seem to be overcome by gravitational torque induced gas flows from other nonaxisymmetric structures. The resulting rates of gas mass inflow range from 0.01 to 50 M☉ yr−1 and are larger for the galaxy center than for the outer disk. Our gas flow maps show the action of nested bars within larger bars for three galaxies. Noncircular streaming motions found in the kinematic maps are larger in the center than in the outer disk and appear to correlate only loosely with the in/out-flow rates as a function of radius. We demonstrate that spiral gas disks are very dynamic systems that undergo strong radial evolution on timescales of a few rotation periods (e.g., 5 × 108 yrs at a radius of 5 kpc), due to the effectiveness of gravitational torques in redistributing the cold galactic gas.