GAMA/H-ATLAS: linking the properties of submm detected and undetected early-type galaxies - I. z = 0.06 sample
GAMA/H-ATLAS: linking the properties of submm detected and undetected early-type galaxies - I. z = 0.06 sample
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GAMA/H-ATLAS：将已检测到的亚毫米级星系和未检测到的早期型星系的特性联系起来 - I. z = 0.06 样本
DOI：
10.1093/mnras/stt310
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发表时间：
2013
影响因子：
4.8
通讯作者：
Agius N
中科院分区：
文献类型：
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作者：
Agius N
我们展示了两个大的、邻近的（0.013≤z≤0.06）早期型星系（etg）样本：一个由220个etg组成的视觉分类样本，该样本使用来自星系和质量集合（GAMA）数据库的源匹配数据，由赫谢尔-天体物理太赫兹大面积巡天（H-ATLAS）的远红外/亚毫米探测创建；以及H-ATLAS未检测到的551个ETGs的视觉分类样本。使用光学发射在线诊断从我们的样品中去除活动星系核。对这些样品进行仔细检查，以确定检测到的亚毫米波与未检测到的ETGs的特征。我们发现两个ETG样本的恒星质量分布相似，但测试其他特性发现了显著差异。检测到的亚微米样品显示出比未检测到的样品具有更低的浓度和ssamrsic指数——这一结果可能与前者中存在灰尘有关。光学和紫外光学颜色也显示出更蓝，这表明尘埃与最近的恒星形成有关。探测到的亚毫米级ETGs的本征有效半径平均大1.5倍。对两个样本的表面密度和GAMA数据库的群数据进行了检查，得出结论：在邻近的宇宙中，有尘埃的etg比无尘埃的etg居住在更稀疏的环境中，尽管最亮的etg的环境差异最小。修正的普朗克函数适用于H-ATLAS探测的光电探测器阵列相机和光谱仪（PACS）和光谱和光度成像接收器（SPIRE）在350 μm SPIRE波段的亚毫米通量密度至少为3σ的ETGs，得到的平均冷尘温度为td = 22.1 K，范围为9-30 K。相应的平均尘埃质量为1.8 × 107M⊙，范围为（0.08 ~ 35.0）× 107M⊙。根据这些拟合计算出的尘埃质量，通过恒星质量归一化，显示出随着恒星质量的减少和颜色的变蓝而增加。基于椭圆型和透镜型的视觉分类，我们发现这两种早期形态的尘埃性质相似。我们得出的结论是，有一群椭圆星系的尘埃质量更大，ssamrsic指数更低，颜色更蓝，而不是众所周知的大质量红色椭圆星系。
We present two large, nearby (0.013 ≤z≤ 0.06) samples of early-type galaxies (ETGs): a visually classified sample of 220 ETGs, created using source-matched data from the Galaxy and Mass Assembly (GAMA) data base with far-infrared/submm detections fromHerschel-Astrophysical Terahertz Large Area Survey (H-ATLAS); and a visually classified sample of 551 ETGs which are undetected with H-ATLAS. Active galactic nuclei are removed from our samples using optical emission-line diagnostics. These samples are scrutinized to determine characteristics of submm detected versus undetected ETGs. We find similarities in the stellar mass distributions of the two ETG samples but testing other properties uncovers significant differences. The submm detected sample is shown to have lower concentration and Sérsic indices than those in the undetected sample – a result which may be linked to the presence of dust in the former. Optical and ultraviolet–optical colours are also shown to be much bluer, indicating that the dust is linked with recent star formation. The intrinsic effective radii are on average 1.5 times larger for the submm detected ETGs. Surface densities and groups data from the GAMA data base are examined for the two samples, leading to the conclusion that dusty ETGs inhabit sparser environments than non-dusty ETGs in the nearby Universe, although environments of the brightest ETGs are shown to differ the least. Modified Planck functions are fit to the H-ATLAS detected Photodetector Array Camera and Spectrometer (PACS) and Spectral and Photometric Imaging Receiver (SPIRE) fluxes for ETGs with submm flux densities of at least 3σ in the 350 μm SPIRE band, giving a resultant mean cold dust temperature ofTd= 22.1 K, with a range of 9–30 K. The corresponding mean dust mass is 1.8 × 107M⊙, with a range of (0.08–35.0) × 107M⊙. The dust masses calculated from these fits, normalized by stellar mass, are shown to increase with decreasing stellar mass and bluer colours. Based on visual classifications of elliptical and lenticular, we find similar dust properties for these two early-type morphologies. We conclude that there is a population of elliptical galaxies which exhibit larger dust masses, lower Sérsic index and bluer colours than the more well-known, massive, red population of ellipticals.