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arXiv 1208.4565astro-ph.GA
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基于脉泽径向速度谱分析的星系螺旋密度波参数重新确定

Redetermination of Galactic Spiral Density Wave Parameters Based on Spectral Analysis of Maser Radial Velocities

A. T. Bajkova, V. V. Bobylev

备注：
20 pages, 4 figures
发表信息：
Astronomy Letters, 2012, Vol. 38, No. 9, 549-561
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摘要：

为了重新确定银河系螺旋密度波参数，我们已经进行了频谱（傅立叶）分析的径向速度为44脉泽与已知的三角函数松弛，自行和视线速度。脉泽分布在一个很宽的银心距离范围内（$(3.5<R<13.2$ kpc），其特征是位置角$θ$在银河XY平面上的分布很广。这需要一个精确的津贴的依赖性的扰动相位的银心距离的对数和对位置的角度的对象。为了提高从大间隔数据序列中提取周期性的重要性，我们提出并实现了一种基于广义最大熵方法的谱重构方法。其结果是，我们已经提取了一个周期性描述的螺旋密度波与以下参数从脉泽径向速度：扰动振幅$f_R = 7.7^{+1.7}_{-1.5}$公里s $^{-1}$，扰动波长$λ=2.2^{+0.4}_{-0.1}$ kpc，螺旋密度波$i=-5^{+0.2^\circ}_{-0.9^\circ}$的螺距角，和太阳的相位在螺旋密度波$χ_\odot= -147^{+3^\circ}_{-17^\circ}$。

英文摘要：

To redetermine the Galactic spiral density wave parameters, we have performed a spectral (Fourier) analysis of the radial velocities for 44 masers with known trigonometric parallaxes, proper motions, and line-of-sight velocities. The masers are distributed in a wide range of Galactocentric distances $(3.5<R<13.2$ kpc) and are characterized by a wide scatter of position angles $θ$ in the Galactic XY plane. This has required an accurate allowance for the dependence of the perturbation phase both on the logarithm of the Galactocentric distances and on the position angles of the objects. To increase the significance of the extraction of periodicities from data series with large gaps, we have proposed and implemented a spectrum reconstruction method based on a generalized maximum entropy method. As a result, we have extracted a periodicity describing a spiral density wave with the following parameters from the maser radial velocities: the perturbation amplitude $f_R = 7.7^{+1.7}_{-1.5}$ km s$^{-1}$, the perturbation wavelength $λ=2.2^{+0.4}_{-0.1}$ kpc, the pitch angle of the spiral density wave $i=-5^{+0.2^\circ}_{-0.9^\circ}$, and the phase of the Sun in the spiral density wave $χ_\odot= -147^{+3^\circ}_{-17^\circ}$.

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