THE STELLAR MASS STRUCTURE OF MASSIVE GALAXIES FROM z = 0 TO z = 2.5: SURFACE DENSITY PROFILES AND HALF-MASS RADII
THE STELLAR MASS STRUCTURE OF MASSIVE GALAXIES FROM z = 0 TO z = 2.5: SURFACE DENSITY PROFILES AND HALF-MASS RADII
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DOI：
10.1088/0004-637x/763/2/73
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发表时间：
2012-08
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影响因子：
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通讯作者：
Daniel Szomoru;M. Franx;P. V. van Dokkum;M. Trenti;G. Illingworth;I. Labbé;P. Oesch
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文献类型：
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作者：
Daniel Szomoru;M. Franx;P. V. van Dokkum;M. Trenti;G. Illingworth;I. Labbé;P. Oesch
我们给出了一个由177个星系组成的质量选择样本的恒星质量表面密度分布，这些样本位于0.5<；z<；2.5，是使用非常深的哈勃空间望远镜光学和近红外数据获得的，包括最近的CANDELS数据。首次对质量大于1010.7 M☉的高红移星系的完整样本进行了精确的恒星质量表面密度分布测量。与以前的工作相比，这项研究的主要优势是表面亮度轮廓被去卷积以进行点扩展函数平滑，从而能够准确地测量星系的结构。表面亮度分布解释了复杂星系结构的贡献，如光环和暗淡的外盘。质量分布是利用径向静止框架ug颜色分布和这些颜色与恒星质量光比之间的良好经验关系得出的。我们从质量分布中得到恒星的半质量半径，并发现它们平均∼比静止框架g带半光半径小25%。这25%的平均大小差异在所有红移中都是相同的，与恒星质量、比恒星形成率、有效表面密度、S指数或星系大小无关。尽管平均而言，半质量大小和半光大小之间的差异不大，但对于大约10%的大质量星系来说，这种差异超过了两倍。这些极端星系大多是延展的盘状系统，中央有很大的凸起。这些结果是可靠的，但如果中心尘埃消失率变高，可能会受到影响。ALMA的观测可以用来探索这种可能性。这些结果为星系增长情景提供了额外的支持，在这些时期，大质量星系通过吸积到其外部区域而增长。
We present stellar mass surface density profiles of a mass-selected sample of 177 galaxies at 0.5 < z < 2.5, obtained using very deep Hubble Space Telescope optical and near-infrared data over the GOODS-South field, including recent CANDELS data. Accurate stellar mass surface density profiles have been measured for the first time for a complete sample of high-redshift galaxies more massive than 1010.7 M☉. The key advantage of this study compared to previous work is that the surface brightness profiles are deconvolved for point-spread function smoothing, allowing accurate measurements of the structure of the galaxies. The surface brightness profiles account for contributions from complex galaxy structures such as rings and faint outer disks. Mass profiles are derived using radial rest-frame ug color profiles and a well-established empirical relation between these colors and the stellar mass-to-light ratio. We derive stellar half-mass radii from the mass profiles, and find that these are on average ∼25% smaller than rest-frame g-band half-light radii. This average size difference of 25% is the same at all redshifts, and does not correlate with stellar mass, specific star formation rate, effective surface density, Sérsic index, or galaxy size. Although on average the difference between half-mass size and half-light size is modest, for approximately 10% of massive galaxies this difference is more than a factor of two. These extreme galaxies are mostly extended, disk-like systems with large central bulges. These results are robust, but could be impacted if the central dust extinction becomes high. ALMA observations can be used to explore this possibility. These results provide added support for galaxy growth scenarios wherein massive galaxies at these epochs grow by accretion onto their outer regions.