论文标题
对流线在太阳能恒星的光谱中移动
Convective Line Shifts in the Spectra of Solar-Type Stars
论文作者
论文摘要
测量了有效温度从4800至6200 K的有效温度的太阳和恒星中的多普勒线变化，并估计了平均连接（颗粒）速度。根据太阳能线对光学深度的偏移的依赖性，建立了恒星线移动的绝对尺度。对于FGK太阳能型恒星，首次获得了对流速度的曲线，这是大气中的高度在150至700 km的大气中的函数。所有这些曲线表明，蓝移的高度减少，这意味着通过光球的颗粒速度放慢到零。在较低的染色层中，观察到强毫克I线的红移，这表明颗粒速度方向的变化与相反的相反，并确认了高度高于600 km的颗粒状逆转的影响。在冷却器k恒星中，肉芽变化随着高度从-50 m/s平均变化，而在较热的FG恒星中，它们从-700升至300 m/s的变化更大。线移曲线的梯度随着有效温度的升高以及重力，金属性和恒星年龄的降低而增加。恒星在所有分析高度上平均的结缔速度从-90增加到-560 m/s，从较冷到更热的恒星。它与大型扰动，光谱线的不对称性和恒星的旋转速度相关。我们还获得了恒星的径向速度，并将它们与Simbad数据进行了比较。我们的分析表明，在确定径向速度时，必须考虑恒星的个体颗粒速度。
The Doppler line shifts in the spectra of the Sun and stars with effective temperatures from 4800 to 6200 K were measured and the average connective (granulation) velocities were estimated. The absolute scale of the line shifts for the stars was established on the basis of the derived dependence of the shifts of solar lines on optical depth. For FGK solar-type stars, curves of convection velocities as a function of the height in the atmosphere in a large range of heights from 150 to 700 km were obtained for the first time. All these curves indicate a decrease in blue shifts with height, which means that the granulation velocities through the photosphere slow down to zero. In the lower chromosphere, red shifts of strong Mg I lines are observed, which indicate a change in the direction of granulation velocities to the opposite and confirm the effects of reversal of granulation at heights above 600 km. In cooler K stars, granulation shifts change with height on average from -50 to 100 m/s, while they change more sharply in hotter FG stars from -700 to 300 m/s. The gradient of the line shift curves increases with an increase in the effective temperature and a decrease in gravity, metallicity, and age of the star. The connective velocity of the star averaged over all analyzed heights increases from -90 to -560 m/s from colder to hotter stars. It correlates with macroturbulence, asymmetry of spectral lines, and the rotation velocity of the star. We also obtained the radial velocities of the stars and compared them with the SIMBAD data. Our analysis has shown that the individual granular velocities of the stars must be taken into account when determining the radial velocities.
