论文标题
巨型低表面亮度星系的体积密度
The volume density of giant low surface brightness galaxies
论文作者
论文摘要
稀有的巨型低表面亮度星系（GLSBG）是当前星系形成范式的应力测试。回答问题“他们有多稀少？”我们估计它们在当地宇宙中的体积密度。 120〜平方米的目视检查。由深层Subaru Hyper Suprime-Cam数据覆盖，由四个团队成员独立执行。我们在$ z \ leq0.1 $中检测到42个巨型迪斯基系统（其中30个孤立的系统），其中$ g $ -band 27.7〜mag〜mag〜mag〜ArcSec $^{ - 2} $ iSophotal Radius或4个圆盘级数$ 4H \ geQ 50 $ 〜kpc，其中25张（包括25个孤立的表面表面）$ege____________________________________。 mag〜arcsec $^{ - 2} $）。 This corresponds to volume densities of 4.70$\times 10^{-5}$ Mpc$^{-3}$ for all galaxies with giant extended discs and 4.04$\times 10^{-5}$ Mpc$^{-3}$ for gLSBGs, which converts to $\sim $12,700 such galaxies in the entire sky out to $z<0.1$.这些估计值与Eagle宇宙流体动力学模拟的结果非常吻合。巨大的磁光星系代表了正常大小的螺旋的体积密度分布的大末端，这表明巨盘的非检查性质。我们观察到新发现的GLSBG中有一个高活性的银河核分数。
Rare giant low surface brightness galaxies (gLSBGs) act as a stress test for the current galaxy formation paradigm. To answer the question `How rare are they?' we estimate their volume density in the local Universe. A visual inspection of 120~sq.~deg. covered by deep Subaru Hyper Suprime-Cam data was performed independently by four team members. We detected 42 giant disky systems (30 of them isolated) at $z\leq0.1$ with either $g$-band 27.7~mag~arcsec$^{-2}$ isophotal radius or four disc scalelengths $4h \geq 50$~kpc, 37 of which (including 25 isolated) had low central surface brightness ($μ_{0,g}\ge 22.7$ mag~arcsec$^{-2}$). This corresponds to volume densities of 4.70$\times 10^{-5}$ Mpc$^{-3}$ for all galaxies with giant extended discs and 4.04$\times 10^{-5}$ Mpc$^{-3}$ for gLSBGs, which converts to $\sim $12,700 such galaxies in the entire sky out to $z<0.1$. These estimates agree well with the result of the EAGLE cosmological hydrodynamical simulation. Giant disky galaxies represent the large-size end of the volume density distribution of normal-sized spirals, suggesting the non-exceptional nature of giant discs. We observe a high active galactic nucleus fraction among the newly found gLSBGs.
