Central velocity dispersion catalogue of LAMOST-DR7 galaxies
Central velocity dispersion catalogue of LAMOST-DR7 galaxies
复制标题
DOI：
10.1093/mnras/staa2409
复制
发表时间：
2020-07
影响因子：
4.8
通讯作者：
N. Napolitano;G. D’ago;Crescenzo Tortora;Gang Zhao;A. Luo;B. Tang;Wei Zhang;Yong Zhang;Rui Li
中科院分区：
文献类型：
--
作者：
N. Napolitano;G. D’ago;Crescenzo Tortora;Gang Zhao;A. Luo;B. Tang;Wei Zhang;Yong Zhang;Rui Li
大天空面积多目标光纤光谱望远镜(LAMOST)是进行宇宙学和星系演化研究的光谱测量的主要设备。LAMOST河外勘测(LEGAS)的第七次数据发布目前已经完成，其中包括193,361个星系的红移。这些源分布在天空的$\sim 11,500$deg$^2$中，与其他成像(SDSS，HSC)和光谱(BOSS)调查基本重叠。星系样本的估计深度、高信噪比和光谱分辨率使LAMOST谱适合于星系速度色散测量，这对于研究星系的结构和形成以及确定其中心暗物质(DM)含量是非常有价值的。我们首次估计了LAMOST足迹中价值86000美元的星系的中心速度弥散。我们使用了一个总结程序来执行频谱拟合，并得到了速度色散测量。通过比较LAMOST速度弥散估计与SDSS和BOSS的速度弥散估计，也对统计误差进行了评估。在统计误差范围内，这两个数据集显示出很好的一致性，特别是当速度分散值被修正为1个有效半径孔径时。我们还给出了一个初步的质量-西格玛--关系，并发现与以前基于局部星系样本的分析是一致的。这些初步结果表明，LAMOST光谱适合于星系速度弥散测量，以补充北半球现有的星系内部运动学目录。我们计划将这一分析扩展到下一次LAMOST数据发布。
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is a major facility to carry out spectroscopic surveys for cosmology and galaxy evolution studies. The seventh data release of the LAMOST ExtraGAlactic Survey (LEGAS) is currently available and including redshifts of 193\,361 galaxies. These sources are spread over $\sim 11\,500$ deg$^2$ of the sky, largely overlapping with other imaging (SDSS, HSC) and spectroscopic (BOSS) surveys. The estimated depth of the galaxy sample, $r\sim17.8$, the high signal-to-noise ratio, and the spectral resolution $R=1800$, make the LAMOST spectra suitable for galaxy velocity dispersion measurements, which are invaluable to study the structure and formation of galaxies and to determine their central dark matter (DM) content. We present the first estimates of central velocity dispersion of $\sim86\,000$ galaxies in LAMOST footprint. We have used a wrap-up procedure to perform the spectral fitting using \textsc{pPXF}, and derive velocity dispersion measurements. Statistical errors are also assessed by comparing LAMOST velocity dispersion estimates with the ones of SDSS and BOSS over a common sample of $\sim51\,000$ galaxies. The two datasets show a good agreement, within the statistical errors, in particular when velocity dispersion values are corrected to 1 effective radius aperture. We also present a preliminary Mass-$\sigma$ relation and find consistency with previous analyses based on local galaxy samples. These first results suggest that LAMOST spectra are suitable for galaxy velocity dispersion measurements to complement the available catalogs of galaxy internal kinematics in the northern hemisphere. We plan to expand this analysis to next LAMOST data releases.