arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1111.0166astro-ph.CO
收藏

星系和质量集合体(GAMA):乌格利兹星系光度函数

Galaxy and Mass Assembly (GAMA): ugriz galaxy luminosity functions

J. Loveday, P. Norberg, I. K. Baldry, S. P. Driver, A. M. Hopkins, J. A. Peacock, S. P. Bamford, J. Liske, J. Bland-Hawthorn, S. Brough, M. J. I. Brown, E. Came… 展开作者

J. Loveday, P. Norberg, I. K. Baldry, S. P. Driver, A. M. Hopkins, J. A. Peacock, S. P. Bamford, J. Liske, J. Bland-Hawthorn, S. Brough, M. J. I. Brown, E. Cameron, C. J. Conselice, S. M. Croom, C. S. Frenk, M. Gunawardhana, D. T. Hill, D. H. Jones, L. S. Kelvin, K. Kuijken, R. C. Nichol, H. R. Parkinson, S. Phillipps, K. A. Pimbblet, C. C. Popescu, M. Prescott, A. S. G. Robotham, R. G. Sharp, W. J. Sutherland, E. N. Taylor, D. Thomas, R. J. Tuffs, E. van Kampen, D. Wijesinghe

摘要:

星系和质量组合(GAMA)是一个研究星系形成和演化的项目,将紫外线到无线电的成像数据与英澳望远镜上AAOmega摄谱仪的光谱数据相结合。使用GAMA第1阶段的数据,在三个观测季节,并纠正各种次要来源的不完整性,我们计算星系光度函数(LF)和它们的演变在ugriz通带。在低红移z < 0.1时,我们发现蓝星系,根据一个依赖于星等但不演化的色切定义,在所有波段上都可以很好地用简单的Schechter函数拟合超过10个星等的范围。红星系和蓝加红的组合样本,需要双幂律Schechter函数来拟合它们在变陡的暗端之前特征星等M* 的LF暗度的下降。这种上升至少部分是由于尘埃变红的盘状星系。我们使用参数拟合和测量红移切片中的分组LF来测量星系LF在红移范围0.002 < z < 0.5内的演化。发现特征光度L* 在所有波段都随着红移而增加,红色星系比蓝色星系表现出更强的光度演化。蓝星系的同动数密度随红移的增加而增加,而红星系的同动数密度则随红移的增加而减少,这与蓝云向红序列的运动是一致的。除了在更高的红移处数量更多之外,蓝色星系也在红移z = 0.2以上的整体光度密度中占主导地位。在较低的红移,亮度密度在riz波段由红色星系主导,在u和g波段由蓝色星系主导。

英文摘要:

Galaxy and Mass Assembly (GAMA) is a project to study galaxy formation and evolution, combining imaging data from ultraviolet to radio with spectroscopic data from the AAOmega spectrograph on the Anglo-Australian Telescope. Using data from phase 1 of GAMA, taken over three observing seasons, and correcting for various minor sources of incompleteness, we calculate galaxy luminosity functions (LFs) and their evolution in the ugriz passbands. At low redshift, z < 0.1, we find that blue galaxies, defined according to a magnitude-dependent but non-evolving colour cut, are reasonably well fit over a range of more than ten magnitudes by simple Schechter functions in all bands. Red galaxies, and the combined blue-plus-red sample, require double power-law Schechter functions to fit a dip in their LF faintward of the characteristic magnitude M* before a steepening faint end. This upturn is at least partly due to dust-reddened disk galaxies. We measure evolution of the galaxy LF over the redshift range 0.002 < z < 0.5 using both a parametric fit and by measuring binned LFs in redshift slices. The characteristic luminosity L* is found to increase with redshift in all bands, with red galaxies showing stronger luminosity evolution than blue galaxies. The comoving number density of blue galaxies increases with redshift, while that of red galaxies decreases, consistent with prevailing movement from blue cloud to red sequence. As well as being more numerous at higher redshift, blue galaxies also dominate the overall luminosity density beyond redshifts z = 0.2. At lower redshifts, the luminosity density is dominated by red galaxies in the riz bands, by blue galaxies in u and g.

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。

↑