标题： 早期类型螺旋星系中的暗物质：NGC 2179和NGC 2775的情况 显示英文标题

标题： Dark matter in early-type spiral galaxies: the case of NGC 2179 and of NGC 2775

摘要： 我们给出了Sa型星系NGC 2179和NGC 2775的恒星和电离气体速度曲线以及速度弥散轮廓。 通过它们的光度轮廓，并对它们的恒星和气体动力学进行建模，我们得出了暗物质和发光物质的质量分布。 这明确表明，在一个盘尺度R_D以内，恒星核球和盘结构构成了全部的引力质量。 暗物质晕可能在内部半径也存在，但在R > 2 R_D时才成为重要的质量成分。 考虑到数据的数量和质量，我们在这些两个明亮星系上的结果是对最近一种说法的有力反例，该说法认为高光度螺旋星系在基本上所有半径上都是暗物质主导的。 显示英文摘要

摘要： We present stellar and ionized-gas velocity curves and velocity dispersion profiles for the Sa galaxies NGC 2179 and NGC 2775. Using their luminosity profiles and modeling both their stellar and gaseous kinematics, we have derived the mass distribution of the dark and the luminous matter. This unambiguously shows that, inside one disk length-scale R_D, the stellar bulge and disk account for the whole gravitating mass. The dark matter halo, likely present also at inner radii, becomes an important mass component only for R > 2 R_D. Giving the quantity and quality of the data, our results on these two luminous galaxies serve as strong counter-example to the recent claim according to which also high-luminosity spirals are dark matter dominated at essentially all radii.