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arXiv 1804.02673astro-ph.GA
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J-PLUS:通过PDF分析进行的恒星/星系形态分类

J-PLUS: Morphological star/galaxy classification by PDF analysis

C. López-Sanjuan, H. Vázquez Ramió, J. Varela, D. Spinoso, R. E. Angulo, D. Muniesa, K. Viironen, D. Cristóbal-Hornillos, A. J. Cenarro, A. Ederoclite, A. Marín… 展开作者

C. López-Sanjuan, H. Vázquez Ramió, J. Varela, D. Spinoso, R. E. Angulo, D. Muniesa, K. Viironen, D. Cristóbal-Hornillos, A. J. Cenarro, A. Ederoclite, A. Marín-Franch, M. Moles, B. Ascaso, S. Bonoli, A. L. Chies-Santos, P. R. T. Coelho, M. V. Costa-Duarte, A. Cortesi, L. A. Díaz-García, R. A. Dupke, L. Galbany, C. Hernández-Monteagudo, R. Logroño-García, A. Molino, A. Orsi, V. M. Placco, L. Sampedro, I. San Roman, G. Vilella-Rojo, D. D. Whitten, C. L. Mendes de Oliveira, L. Sodré

摘要:

我们的目标是形态学分类的J-PLUS早期数据发布(EDR)的图像中确定的来源到紧凑(恒星)或扩展(星系)使用合适的贝叶斯分类器。J-PLUS源在r波段强度与浓度平面上表现出两种不同的总体,对应于紧凑源和扩展源。我们建模的两个人口分布与偏高斯紧凑的对象和对数正态函数的扩展。基于J-PLUS EDR数据,推导出的模型和数密度先验被用来估计一个源是恒星或星系的贝叶斯概率。这一过程是逐点应用的,以考虑到不同的观测条件和天空位置。最后,我们结合了形态学的信息,从g,r,和i宽频带,以提高低信号噪声源的分类。导出的概率被用来计算逐点计数的恒星和星系。前者随着我们接近银河系盘而增加,后者在探测区域内相似。在r ~ 21范围内,与SDSS的比较结果令人满意,恒星和星系的数目一致,浓度和(g-i)色空间的分布也一致。我们实现了一个形态的恒星/星系分类器的基础上PDF分析,提供有意义的概率J-PLUS源一个级别深(r ~ 21)比经典的布尔分类。这些概率适用于J-PLUS EDR 31.7 ° 2中15 < r < 21的150 k颗恒星和101 k个星系的统计研究。在分类器的未来版本中,我们将包括来自12个光度带的J-PLUS颜色信息。

英文摘要:

Our goal is to morphologically classify the sources identified in the images of the J-PLUS early data release (EDR) into compact (stars) or extended (galaxies) using a suited Bayesian classifier. J-PLUS sources exhibit two distinct populations in the r-band magnitude vs. concentration plane, corresponding to compact and extended sources. We modelled the two-population distribution with a skewed Gaussian for compact objects and a log-normal function for the extended ones. The derived model and the number density prior based on J-PLUS EDR data were used to estimate the Bayesian probability of a source to be star or galaxy. This procedure was applied pointing-by-pointing to account for varying observing conditions and sky position. Finally, we combined the morphological information from g, r, and i broad bands in order to improve the classification of low signal-to-noise sources. The derived probabilities are used to compute the pointing-by-pointing number counts of stars and galaxies. The former increases as we approach to the Milky Way disk, and the latter are similar across the probed area. The comparison with SDSS in the common regions is satisfactory up to r ~ 21, with consistent numbers of stars and galaxies, and consistent distributions in concentration and (g - i) colour spaces. We implement a morphological star/galaxy classifier based on PDF analysis, providing meaningful probabilities for J-PLUS sources to one magnitude deeper (r ~ 21) than a classical boolean classification. These probabilities are suited for the statistical study of 150k stars and 101k galaxies with 15 < r < 21 present in the 31.7 deg2 of the J-PLUS EDR. In a future version of the classifier, we will include J-PLUS colour information from twelve photometric bands.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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