Investigating Clumpy Galaxies in the Sloan Digital Sky Survey Stripe 82 Using the Galaxy Zoo
Investigating Clumpy Galaxies in the Sloan Digital Sky Survey Stripe 82 Using the Galaxy Zoo
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DOI：
10.3847/1538-4357/abed5b
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发表时间：
2020-11
期刊：
影响因子：
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通讯作者：
V. Mehta;C. Scarlata;L. Fortson;H. Dickinson;Dominic Adams;J. Chevallard;S. Charlot;Melanie Beck;S. Kruk;B. Simmons
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文献类型：
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作者：
V. Mehta;C. Scarlata;L. Fortson;H. Dickinson;Dominic Adams;J. Chevallard;S. Charlot;Melanie Beck;S. Kruk;B. Simmons
巨大的恒星形成团是高红移恒星形成星系中普遍存在的一个共同特征，在形成它们的混沌形态方面发挥着关键作用，但它们的性质和在星系演化中的作用仍有待充分了解。大多数研究团块的努力都集中在高红移，而局部团块研究往往受到样本量较小的影响。在这项工作中，我们提出了对局部宇宙中的团簇属性的分析，并首次使用具有统计意义的样本进行了分析。在公民科学支持的银河系动物园：哈勃项目的帮助下，我们选择了斯隆数字天空勘测条纹82星系中92个z<；0.06个块状星系的样本。在这个样本中，我们使用基于对比度的图像分析算法来识别543个团块，并执行光度测量以及估计它们的恒星种群属性。我们的z<；0.06块状样品的整体性能可与高红移块状材料相媲美。然而，与高红移研究相反，我们没有发现集束年龄或质量作为其银河中心距离的函数的梯度的证据。我们的结果挑战了局部宇宙中团块演化的向内迁移情景，潜在地表明了非原位团块的更大贡献和/或更长的团块迁移时间尺度。
Giant, star-forming clumps are a common feature prevalent among high-redshift star-forming galaxies and play a critical role in shaping their chaotic morphologies and yet, their nature and role in galaxy evolution remains to be fully understood. A majority of the effort to study clumps has been focused at high redshifts, and local clump studies have often suffered from small sample sizes. In this work, we present an analysis of clump properties in the local universe, and for the first time, performed with a statistically significant sample. With the help of the citizen science-powered Galaxy Zoo: Hubble project, we select a sample of 92 z < 0.06 clumpy galaxies in Sloan Digital Sky Survey Stripe 82 galaxies. Within this sample, we identify 543 clumps using a contrast-based image analysis algorithm and perform photometry as well as estimate their stellar population properties. The overall properties of our z < 0.06 clump sample are comparable to the high-redshift clumps. However, contrary to the high-redshift studies, we find no evidence of a gradient in clump ages or masses as a function of their galactocentric distances. Our results challenge the inward migration scenario for clump evolution for the local universe, potentially suggesting a larger contribution of ex situ clumps and/or longer clump migration timescales.