arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1506.01201astro-ph.GA
收藏

WINGS星系团的星系光度函数

Galaxy Luminosity Functions in WINGS clusters

A. Moretti, D. Bettoni, B. M. Poggianti, G. Fasano, J. Varela, M. D'Onofrio, B. Vulcani, A. Cava, J. Fritz, W. J. Couch, M. Moles, P. Kjærgaard

摘要:

利用WINGS巡天的V波段测光,我们导出了邻近星系团的星系光度函数(LF)。这个样本是完整的Mv=-15.15,它是均匀的,从而允许研究具有不同特征的聚类的无偏样本。我们构建了72个原来的76个WINGS集群的光度LF,只排除那些没有速度色散估计。对于每个星系团,我们得到了LF的半径=0.5 x r 200的区域中的星系,并拟合它们与单和双Schechter函数。我们还推导出整个样本的复合LF,以及那些属于不同形态类的复合LF。最后,我们得出的光谱累积LF为2009年星系团成员。双Schechter拟合参数既不与集群的速度色散,也不与X射线光度。平均而言,我们的Schechter拟合斜率的中值与附近星系团的测量值一致,但没有SDSS等大型调查得出的结果那么陡峭。早期类型星系的数量在各个量级上都超过了晚期类型星系,但早期和晚期类型对LF的微弱末端的贡献是相同的。最后,光谱LF与A2199,A85和室女座的光谱LF非常一致,并且在明亮的星等上与光度LF非常一致(两者都可用)。不同聚类的LF存在很大的差异。然而,这种扩展并不是由LF形状与星系团特征如X射线光度或速度色散的相关性引起的。暗端比以前推导的(α_f=-1.7)更平坦,与数值模拟预测的不一致。

英文摘要:

Using V band photometry of the WINGS survey, we derive galaxy luminosity functions (LF) in nearby clusters. This sample is complete down to Mv=-15.15, and it is homogeneous, thus allowing the study of an unbiased sample of clusters with different characteristics. We constructed the photometric LF for 72 out of the original 76 WINGS clusters, excluding only those without a velocity dispersion estimate. For each cluster we obtained the LF for galaxies in a region of radius=0.5 x r200, and fitted them with single and double Schechter's functions. We also derive the composite LF for the entire sample, and those pertaining to different morphological classes. Finally we derive the spectroscopic cumulative LF for 2009 galaxies that are cluster members. The double Schechter fit parameters are neither correlated with the cluster velocity dispersion, nor with the X-ray luminosity. Our median values of the Schechter's fit slope are, on average, in agreement with measurements of nearby clusters, but are less steep that those derived from large surveys, such as the SDSS. Early--type galaxies outnumber late-types at all magnitudes, but both early and late types contribute equally to the faint end of the LF. Finally, the spectroscopic LF is in excellent agreement with the ones derived for A2199, A85 and Virgo, and with the photometric one at the bright magnitudes (where both are available). There is a large spread in the LF of different clusters. However, this spread is not caused by correlation of the LF shape with cluster characteristics such as X--ray luminosity or velocity dispersions. The faint end is flatter than what previously derived (alpha_f=-1.7) at odds with what predicted from numerical simulations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑