论文标题
当地螺旋星系中蓝色超级恒星的光谱研究：andromeda和Triangulum
A spectroscopic study of blue supergiant stars in Local Group spiral galaxies: Andromeda and Triangulum
论文作者
论文摘要
分析了分布在本地组螺旋星系M 31和M 33磁盘上的蓝色超级恒星的低分辨率Lamost和Keck光谱，以确定恒星有效的温度，重力，金属性和变红。星系中心（以太阳能单位）为0.30 \ pm0.09 $和$ 0.11 \ pm0.04 $ and $ -0.37 \ pm0.13 \ pm0.13 $ -0.13 $ dex/$ r_ {25} $ r_ {25} $ pm0.36 $ pm0.16 $ r_和r_的$ -0.16 $ r_和r_的$ -0.16 $ r_和r r r r_和r r r r_ pm0.13 $ r_和dex $ r r r_ pm0.16 $ r_和r r r r_ pm0.37 \ pm0.16 $ r_和r r r r_ pm0.16 $ r_和r r_分别为33。对于M 33，金属性的二维分布表明偏离了Azimutal对称性，其峰值峰值峰值。蓝色超级恒星的通量加权重力 - 劳度关系用于确定24.51 $ \ pm的距离模量为M 31和24.93 $ \ pm $ \ pm $ \ pm $ 0.07 mag for M 33。对于M 33，基于FGLR的距离大于Cepheids研究的距离，但它与远程淘汰二进制，行星星云，长期变量和红色巨型分支的尖端的工作非常吻合。
Low-resolution LAMOST and Keck spectra of blue supergiant stars distributed over the disks of the Local Group spiral galaxies M 31 and M 33 are analyzed to determine stellar effective temperatures, gravities, metallicities, and reddening. Logarithmic metallicities at the center of the galaxies (in solar units) of $0.30\pm0.09$ and $0.11\pm0.04$ and metallicity gradients of $-0.37\pm0.13$ dex/$R_{25}$ and $-0.36\pm0.16$ dex/$R_{25}$ are measured for M 31 and M 33, respectively. For M 33 the 2-dimensional distribution of metallicity indicates a deviation from azimutal symmetry with an off-centre peak. The flux-weighted gravity-luminosity relationship of blue supergiant stars is used to determine a distance modulus of 24.51$\pm$0.13 mag for M 31 and 24.93$\pm$0.07 mag for M 33. For M 31 the flux-weighted gravity--luminosity relationship (FGLR) distance agrees well with other methods. For M 33 the FGLR-based distance is larger than the distances from Cepheids studies but it is in good agreement with work on eclipsing binaries, planetary nebulae , long-period variables, and the tip of the red giant branch.
