One Hundred SMUDGes in S-PLUS: Ultra-diffuse Galaxies Flourish in the Field
One Hundred SMUDGes in S-PLUS: Ultra-diffuse Galaxies Flourish in the Field
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DOI：
10.3847/1538-4365/ab7660
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发表时间：
2020-02
期刊：
影响因子：
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通讯作者：
C. E. Barbosa;D. Zaritsky;R. Donnerstein;Huanian Zhang;A. Dey;C. M. D. Oliveira;L. Sampedro;A. Mol
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文献类型：
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作者：
C. E. Barbosa;D. Zaritsky;R. Donnerstein;Huanian Zhang;A. Dey;C. M. D. Oliveira;L. Sampedro;A. Mol
我们首次在该领域系统地研究了超漫射星系（udg）的恒星群，将SMUDGes巡天的大面积搜索和udg的表征与S-PLUS巡天的十二波段光学光度测量相结合。基于udg光学颜色的贝叶斯模型，我们确定了分布在条带82区域约330°2区域内的100颗udg的年龄、金属丰度和恒星质量。我们发现，场udg的恒星质量和金属丰度与在星团中观察到的相似，并遵循先前在矮星系和巨型星系研究中定义的趋势。然而，与星团中的udg相比，野外udg具有更年轻的光度加权年龄。我们将这一结果解释为磁场udg具有更长的恒星形成历史，包括一些在低水平下继续形成恒星到现在的恒星。最后，我们研究了恒星种群尺度关系，表明udg作为一个种群与其他低表面亮度星系相似。
We present the first systematic study of the stellar populations of ultra-diffuse galaxies (UDGs) in the field, integrating the large area search and characterization of UDGs by the SMUDGes survey with the twelve-band optical photometry of the S-PLUS survey. Based on Bayesian modeling of the optical colors of UDGs, we determine the ages, metallicities, and stellar masses of 100 UDGs distributed in an area of ∼330 deg2 in the Stripe 82 region. We find that the stellar masses and metallicities of field UDGs are similar to those observed in clusters and follow the trends previously defined in studies of dwarf and giant galaxies. However, field UDGs have younger luminosity-weighted ages than do UDGs in clusters. We interpret this result to mean that field UDGs have more extended star formation histories, including some that continue to form stars at low levels to the present time. Finally, we examine stellar population scaling relations that show that UDGs are, as a population, similar to other low surface brightness galaxies.