论文标题
烛台商品中星系的表面亮度演变最高$ z \ sim 6 $：高Z星系是独特的或未被发现
Surface Brightness Evolution of Galaxies in the CANDELS GOODS Fields up to $z \sim 6$: High-z Galaxies are Unique or Remain Undetected
论文作者
论文摘要
我们使用各种深哈勃太空望远镜成像研究了剩下的框架紫外线（UV，$λ\ sim2000 $Å）表面亮度（SB）最高$ z \ sim6 $的星系演变。紫外线SB是大多数年轻恒星发射密度的量度，与恒星形成速率，初始质量功能，冷气质量密度，灰尘衰减和星系尺寸演变的未知组合相关。除了物理效应外，与大小不同，SB是确定星系可检测性的更直接的方法。我们发现内在的SB分布中的一个非常强大的演变，它偏向于$（1+z）^{3} $，在$ z = 6 $ to $ z = 1 $之间减少了4-5 mag arcsec $^{ - 2} $。就紫外线亮度，大小或尘埃灭绝的演变而言，这种变化比预期的要大得多，我们证明了这种进化是“不自然的”，并且由于选择偏见。我们还发现质量和紫外线SB之间没有强大的相关性。因此，深HST成像无法发现遥远宇宙中所有最大的星系。通过模拟，我们表明，只有$ \ sim15 $ \％可以在$ z = 2 $下检测到的星系，以高$ z $检测到。我们此外，通过研究内在的SB和恒星形成率之间的关系，以高$ z $探讨了高SB星系的可能起源。我们得出的结论是，超高的SB星系是由非常富含气体的密集星系产生的，这些星系处于独特的进化阶段，可能由合并产生。此类星系的类似物在相对附近的宇宙中不存在。
We investigate the rest-frame Ultraviolet (UV, $λ\sim2000$Å) surface brightness (SB) evolution of galaxies up to $z\sim6$ using a variety of deep Hubble Space Telescope imaging. UV SB is a measure of the density of emission from mostly young stars and correlates with an unknown combination of star formation rate, initial mass function, cold gas mass density, dust attenuation, and the size evolution of galaxies. In addition to physical effects, the SB is, unlike magnitude, a more direct way in which a galaxy's detectability is determined. We find a very strong evolution in the intrinsic SB distribution which declines as $(1+z)^{3}$, decreasing by 4-5 mag arcsec$^{-2}$ between $z=6$ to $z=1$. This change is much larger than expected in terms of the evolution in UV luminosity, sizes or dust extinction and we demonstrate that this evolution is 'unnatural' and due to selection biases. We also find no strong correlation between mass and UV SB. Thus, deep HST imaging is unable to discover all of the most massive galaxies in the distant universe. Through simulations we show that only $\sim15$\% of galaxies that we can detect at $z=2$ would be detected at high-$z$. We furthermore explore possible origins of high SB galaxies at high-$z$ by investigating the relationship between intrinsic SB and star formation rates. We conclude that ultra-high SB galaxies are produced by very gas rich dense galaxies which are in a unique phase of evolution, possibly produced by mergers. Analogues of such galaxies do not exist in the relatively nearby universe.
