Statistics of Velocity from Spectral Data: Modified Velocity Centroids
Statistics of Velocity from Spectral Data: Modified Velocity Centroids
复制标题
光谱数据的速度统计：修改后的速度质心
DOI：
10.1086/377427
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
A. Esquivel
中科院分区：
文献类型：
--
作者：
A. Lazarian;A. Esquivel
我们解决的问题，研究星际湍流使用谱线数据。我们找到一个标准时，速度质心可以提供值得信赖的速度统计。为了扩大形心应用的范围，我们构建了一种称为“修改速度形心”（MVC）的度量，并推导出将修改形心的二维谱与底层三维速度谱联系起来的分析解。我们测试我们的结果使用合成地图构建的数据通过模拟可压缩MHD湍流。我们表明，MVC是互补的速度通道分析技术。它们一起使用，使速度谱指数的测定在更广泛的天体物理情况下更可靠。
We address the problem of studying interstellar turbulence using spectral line data. We find a criterion when the velocity centroids may provide trustworthy velocity statistics. To enhance the scope of centroid applications, we construct a measure that we term "modified velocity centroids" (MVCs) and derive an analytical solution that relates the two-dimensional spectra of the modified centroids with the underlying three-dimensional velocity spectrum. We test our results using synthetic maps constructed with data obtained through simulations of compressible MHD turbulence. We show that the MVCs are complementary to the Velocity Channel Analysis technique. Employed together, they make the determination of the velocity spectral index more reliable for a wider variety of astrophysical situations.