We present a spectroscopic catalog of 70,841 visually inspected M dwarfs from the seventh data release of the Sloan Digital Sky Survey. For each spectrum, we provide measurements of the spectral type, a number of molecular band heads, and the Hα, Hβ, Hγ, Hδ, and Ca II K emission lines. In addition, we calculate the metallicity-sensitive parameter ζ and identify a relationship between ζ and the g – r and r – z colors of M dwarfs. We assess the precision of our spectral types (which were assigned by individual examination), review the bulk attributes of the sample, and examine the magnetic activity properties of M dwarfs, in particular those traced by the higher order Balmer transitions. Our catalog is cross-matched to Two Micron All Sky Survey infrared data, and contains photometric distances for each star. Finally, we identify eight new late-type M dwarfs that are possibly within 25?pc of the Sun. Future studies will use these data to thoroughly examine magnetic activity and kinematics in late-type M dwarfs and examine the chemical and dynamical history of the local Milky Way.
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机译：我们从斯隆数字天空调查的第七次数据发布中提供了70,841目视检查的小矮人的光谱目录。对于每个光谱，我们提供光谱类型，多个分子带头以及Hα，Hβ，Hγ，Hδ和Ca II K发射谱线的测量值。另外，我们计算了对金属性敏感的参数ζ，并确定了ζ与M个矮星的g – r和r – z颜色之间的关系。我们评估了光谱类型的精度（这些光谱类型是通过单独检查确定的），审查了样品的整体属性，并检查了M个小矮星的磁活动特性，尤其是那些由高阶Balmer跃迁所跟踪的磁活动特性。我们的目录与“两微米全天候测量”红外数据交叉匹配，并且包含每颗恒星的光度距离。最后，我们确定了八个新的晚型M矮星，它们可能在距太阳25？pc的范围内。未来的研究将使用这些数据来彻底检查晚期M型矮星的磁活动和运动学，并检查当地银河系的化学和动力学历史。
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