论文标题
条对气相丰度梯度的影响。 ii。光度依赖性扁平
Bar effect on gas-phase abundance gradients. II. Luminosity-dependent flattening
论文作者
论文摘要
我们在这里提出了一个项目的第二部分，该项目旨在解决螺旋星系气相中金属径向分布的问题问题的争议。在纸上，我们提出了属于51个附近星系的2800多个HII区域的汇编，我们从同质方法中得出了化学丰度和径向丰富的曲线。在本文中，我们分别分别分别分别为未限制的星系，分析了12+log（O/h）和原木（N/O）的衍生气相径向丰度曲线，并发现依赖星系光度的星系中的斜率和未挂钩的星系之间的差异。这是由于两种类型星系的丰度梯度（以DEX/kpc为单位）的依赖性不同：在我们认为梯度的星系样品中，在整个亮度范围内强烈范围的星系中似乎相当浅，而无端星系的剖面斜度则变得更加陡峭。因此，我们仅检测到较低的光度（下质量）星系（M_B>〜-19.5或M_* <〜10^{10.4} M_SUN）的斜率差异。我们讨论了圆盘的演化和横杆和螺旋臂引起的径向混合的角度。我们的结果调和了先前的差异发现，这些发现因样品星系的光度（质量）分布以及可能的丰富诊断而偏向。
We present here the second part of a project that aims at solving the controversy on the issue of the bar effect on the radial distribution of metals in the gas-phase of spiral galaxies. In Paper I we presented a compilation of more than 2800 HII regions belonging to 51 nearby galaxies for which we derived chemical abundances and radial abundance profiles from a homogeneous methodology. In this paper we analyse the derived gas-phase radial abundance profiles of 12+log(O/H) and log(N/O), for barred and unbarred galaxies separately, and find that the differences in slope between barred and unbarred galaxies depend on galaxy luminosity. This is due to a different dependence of the abundance gradients (in dex/kpc) on luminosity for the two types of galaxies: In the galaxy sample that we consider the gradients appear to be considerably shallower for strongly barred galaxies in the whole luminosity range, while profile slopes for unbarred galaxies become steeper with decreasing luminosity. Therefore, we only detect differences in slope for the lower luminosity (lower mass) galaxies (M_B >~ -19.5 or M_* <~ 10^{10.4} M_sun). We discuss the results in terms of the disc evolution and radial mixing induced by bars and spiral arms. Our results reconcile previous discrepant findings that were biased by the luminosity (mass) distribution of the sample galaxies and possibly by the abundance diagnostics employed.
