The Intrinsic Shapes of Low Surface Brightness Galaxies (LSBGs): A Discriminant of LSBG Galaxy Formation Mechanisms
The Intrinsic Shapes of Low Surface Brightness Galaxies (LSBGs): A Discriminant of LSBG Galaxy Formation Mechanisms
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DOI：
10.3847/1538-4357/ac15f0
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发表时间：
2021-06
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通讯作者：
Erin Kado-Fong;M. Petrescu;Majid Mohammad;J. Greco;J. Greene;E. Adams;Song Huang;L. Leisman;F. Munshi;D. Tanoglidis;Jordan Van Nest
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作者：
Erin Kado-Fong;M. Petrescu;Majid Mohammad;J. Greco;J. Greene;E. Adams;Song Huang;L. Leisman;F. Munshi;D. Tanoglidis;Jordan Van Nest
我们使用低表面亮度星系（LSBG）样本创建的超Suprime-Cam斯巴鲁战略计划（781个星系），暗能量调查（20977个星系），和遗产调查（通过H i检测选择在阿雷西博遗产快速ALFA调查，188个星系）来推断LSBG人口的内在形状分布。为了考虑到在构建LSBG样品时采用的表面亮度切割的效果，我们在形状推断中同时对投影椭圆率和表观表面亮度进行建模。我们发现，LSBG样品的特点是扁球体，红色和蓝色LSBG之间没有显着差异。这种推断的形状分布与超扩散星系团样本的类似推断非常一致，表明环境在确定LSBG的内在形状方面并不起关键作用。我们还发现一些证据表明，LSBG比同样大质量的高表面亮度矮星更厚。我们比较我们的结果，从当代宇宙学模拟的内在形状措施，并发现所观察到的LSBG的内在形状放置相当大的限制，这样的星系的形成路径。特别是，LSBG生产通过迁移的星星形成大半径产生的内在形状与我们的观测结果很好地吻合。
We use the low surface brightness galaxy (LSBG) samples created from the Hyper Suprime-Cam Subaru Strategic Program (781 galaxies), the Dark Energy Survey (20977 galaxies), and the Legacy Survey (selected via H i detection in the Arecibo Legacy Fast ALFA Survey, 188 galaxies) to infer the intrinsic shape distribution of the LSBG population. To take into account the effect of the surface brightness cuts employed when constructing LSBG samples, we simultaneously model both the projected ellipticity and the apparent surface brightness in our shape inference. We find that the LSBG samples are well characterized by oblate spheroids, with no significant difference between red and blue LSBGs. This inferred shape distribution is in good agreement with similar inferences made for ultra-diffuse cluster galaxy samples, indicating that environment does not play a key role in determining the intrinsic shape of LSBGs. We also find some evidence that LSBGs are more thickened than similarly massive high surface brightness dwarfs. We compare our results to intrinsic shape measures from contemporary cosmological simulations, and find that the observed LSBG intrinsic shapes place considerable constraints on the formation path of such galaxies. In particular, LSBG production via the migration of star formation to large radii produces intrinsic shapes in good agreement with our observational findings.