GAS-PHASE OXYGEN GRADIENTS IN STRONGLY INTERACTING GALAXIES. I. EARLY-STAGE INTERACTIONS
GAS-PHASE OXYGEN GRADIENTS IN STRONGLY INTERACTING GALAXIES. I. EARLY-STAGE INTERACTIONS
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DOI：
10.1088/0004-637x/723/2/1255
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发表时间：
2010-09
期刊：
影响因子：
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通讯作者：
D. Rupke;L. Kewley;Li-Hsin Chien
中科院分区：
文献类型：
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作者：
D. Rupke;L. Kewley;Li-Hsin Chien
一个共识正在形成，相互作用的星系显示出压抑的核气体金属丰度相比，孤立的恒星形成星系。模拟结果表明，这种核丰度不足是由相互作用引起的贫金属气体的流入，这种流入同时在强相互作用星系的径向金属丰度梯度。我们提出的金属丰度超过300 H II区域的样本中的16个螺旋，强烈相互作用的星系对的质量比接近统一的成员。在这些星系中的反投影径向梯度大约是那些孤立的，晚型螺旋控制样本的一半。详细的梯度与模拟的比较显示出显着的协议在梯度分布，梯度和核丰度不足之间的关系，以及从一条直线的轮廓偏差的形状。总之，这些证据最终表明，强烈相互作用的星系在今天经历核金属稀释由于气体流入，以及显着平坦的气相金属丰度梯度，目前的模拟可以在统计水平上稳健地再现这种行为。
A consensus is emerging that interacting galaxies show depressed nuclear gas metallicities compared to isolated star-forming galaxies. Simulations suggest that this nuclear underabundance is caused by interaction-induced inflow of metal-poor gas and that this inflow concurrently flattens the radial metallicity gradients in strongly interacting galaxies. We present metallicities of over 300 H ii regions in a sample of 16 spirals that are members of strongly interacting galaxy pairs with mass ratio near unity. The deprojected radial gradients in these galaxies are about half of those in a control sample of isolated, late-type spirals. Detailed comparison of the gradients with simulations shows remarkable agreement in gradient distributions, the relationship between gradients and nuclear underabundances, and the shape of profile deviations from a straight line. Taken together, this evidence conclusively demonstrates that strongly interacting galaxies at the present day undergo nuclear metal dilution due to gas inflow, as well as significant flattening of their gas-phase metallicity gradients, and that current simulations can robustly reproduce this behavior at a statistical level.