Systematically Measuring Ultra-diffuse Galaxies (SMUDGes). II. Expanded Survey Description and the Stripe 82 Catalog
Systematically Measuring Ultra-diffuse Galaxies (SMUDGes). II. Expanded Survey Description and the Stripe 82 Catalog
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DOI：
10.3847/1538-4365/ac2607
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
D. Zaritsky;R. Donnerstein;A. Karunakaran;C. E. Barbosa;A. Dey;J. Kadowaki;K. Spekkens;Huanian Zhang
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文献类型：
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作者：
D. Zaritsky;R. Donnerstein;A. Karunakaran;C. E. Barbosa;A. Dey;J. Kadowaki;K. Spekkens;Huanian Zhang
我们提出了226个大型超漫射星系（UDG）候选者（如bbbb5）。″3,μ 0,g > 24 mag arcsec−2)在SDSS Stripe 82区域使用我们改进的程序恢复，预计处理整个Legacy survey足迹。这些进展包括较少约束的结构参数拟合，扩展的小波滤波标准，考虑银河尘埃，基于模拟源的参数不确定性和完整性估计，以及我们的自动候选分类的改进。我们在μ 0，g范围内的灵敏度比该区域最大的已发表星表的灵敏度低约1等。使用我们的完整性校正样本，我们发现(1)在我们的调查极限（~ 26.5等弧秒−2）内，作为μ 0，g的函数，UDG候选者的数量没有显著下降；(2)蓝色候选人的ssamrsi值较小；(3)大多数蓝色（g - r < 0.45等）候选序列具有μ 0，g≤25等arcsec−2，并将逐渐褪色以填充我们观察到的UDG红色序列至~ 26.5等arcsec−2；(4)任何明显低于我们的μ 0，g灵敏度极限的红色udg都不是我们样品中蓝色udg的后代；(5) μ 0和g较低的候选物倾向于较小的n。我们预计最终的SMUDGes样本将包含约30倍的候选物。
We present 226 large ultra-diffuse galaxy (UDG) candidates (r e > 5.″3, μ 0,g > 24 mag arcsec−2) in the SDSS Stripe 82 region recovered using our improved procedure developed in anticipation of processing the entire Legacy Surveys footprint. The advancements include less constrained structural parameter fitting, expanded wavelet filtering criteria, consideration of Galactic dust, estimates of parameter uncertainties and completeness based on simulated sources, and refinements of our automated candidate classification. We have a sensitivity ∼1 mag fainter in μ 0,g than the largest published catalog of this region. Using our completeness-corrected sample, we find that (1) there is no significant decline in the number of UDG candidates as a function of μ 0,g to the limit of our survey (∼26.5 mag arcsec−2); (2) bluer candidates have smaller Sérsic n; (3) most blue (g–r < 0.45 mag) candidates have μ 0,g ≲ 25 mag arcsec−2 and will fade to populate the UDG red sequence we observe to ∼26.5 mag arcsec−2; (4) any red UDGs that exist significantly below our μ 0,g sensitivity limit are not descendent from blue UDGs in our sample; and (5) candidates with lower μ 0,g tend to smaller n. We anticipate that the final SMUDGes sample will contain ∼30 × as many candidates.