标题： 来自星系中良好混合指数盘的虚假尘埃屏幕 显示英文标题

标题： Bogus dust screens from well mixed exponential disks in galaxies

摘要： 螺旋星系次小轴上的V-K颜色通常随着距离的增加从红色变为蓝色，给人一种近侧被尘埃系统性遮挡的印象。 这种尘埃屏的优选方向是不太可能的。 在这里，我们表明，嵌入在指数盘中的尘埃层产生的常见消光具有相同的效果，使得随着倾斜度的增加，近侧系统性地变得更红。 以银河系NGC 2841为例进行建模，其中V-K曲线在中心区域表现出显著的不对称性，并实际上呈阶梯状。 我们预测，在远红外波长200微米处，同一尘埃的次小轴发射轮廓将比光学轮廓对称得多，这意味着次小轴两侧的尘埃柱密度几乎相等。 显示英文摘要

摘要： The V-K colours along the minor axes of spiral galaxies typically change from red to blue with increasing distance, giving the impression that the near side is systematically screened by dust. Such a preferred orientation for dust screens is unlikely. Here we show that common extinction from the embedded dust layer in an exponential disk has the same effect, making the near side systematically redder as the inclination increases. The galaxy NGC 2841 is modelled as an example, where the V-K profile is profoundly asymmetric and actually step-like across the centre. We predict that the minor axis emission profile of the same dust in the far-infrared, at wavelength 200 microns, will be much more symmetric than the optical profiles, implying nearly equal column densities of dust on both sides of the minor axis.