标题： 射电星系中的有效半径和颜色梯度 显示英文标题

标题： Effective Radii and Color Gradients in Radio Galaxies

摘要： 我们给出了 MRC (Molonglo Reference Catalogue) 射电星系样本和正常星系对照样本在 B 和 R 波段的 de Vaucouleurs 有效半径。我们用这两个波段尺度长度的比值作为指示器，表明射电星系内区更频繁地表现出过量的蓝颜色，这与对照样本不同。我们还表明，即使传统的颜色梯度太嘈杂而无法达到此目的，尺度长度比值仍可作为一种有用的径向颜色变化指示器。 显示英文摘要

摘要： We present de Vaucouleurs' effective radii in B and R bands for a sample of Molonglo Reference Catalogue radio galaxies and a control sample of normal galaxies. We use the ratio of the scale lengths in the two bands as an indicator to show that the radio galaxies tend to have excess of blue color in their inner region much more frequently than the control galaxies. We show that the scale length ratio is a useful indicator of radial color variation even when the conventional color gradient is too noisy to serve the purpose.