论文标题
暂定$ \ sim $ 1000 km s $^{ - 1} $偏移[CII] 158 $μ$ m和ly $ ly $α$ line line juins在$ z = 7.2 $的星形星系中排放
A tentative $\sim$1000 km s$^{-1}$ offset between the [CII] 158 $μ$m and Ly$α$ line emission in a star-forming galaxy at $z = 7.2$
论文作者
论文摘要
GN-108036是$ z = 7.21 $的星形星系，也是北半球最遥远的来源之一。基于北部扩展毫米阵列（NOEMA）的观察结果，我们在这里报告了[CII]线以$ \of4σ$显着性的暂定检测。从休息框架紫外线（UV）排放中，集成的[CII]线排放在空间上被空间偏移。总的[CII]光度（$ L _ {\ rm [CII]} = 2.7 \ times10^8〜l _ {\ odot} $）与[CII]亮度和星形形成率（SFR）之间的关系一致，在附近和高$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $星形的人星系中。更有趣的是，[CII]线相对于Ly $α$线的蓝光升级为$ 980 \ pm10 $ km s $^{ - 1} $。如果得到确认，这对应于迄今为止在LY $α$线和$ z \ gtrsim6 $的非共振线之间报告的最大速度偏移。根据在其他高红移星系中观察到的趋势，在GN-108036中，大的$α$速度抵消与其低$ ly $ ly $α$等效宽度和高紫外线绝对幅度一致。基于ly $α$辐射转移模型的扩展壳，GN-108036中的大$α$速度偏移可以解释为氢气的大柱密度的存在和/或流出速度$ v _ {\ rm out} \simΔV_$ sim aim sim aim sim aim y sim aim sim aim aim s $^{ - 1} $。我们还报告了GN-108036以东的$ \ sim30 $ kpc的潜在星系伴侣的3 $σ$检测，以类似的系统性速度，并且没有对应的REST型UV排放。
GN-108036 is a star-forming galaxy at $z=7.21$, and one of the most distant known sources in the Northern hemisphere. Based on observations from the NOrthern Extended Millimeter Array (NOEMA), here we report the tentative detection of the [CII] line at $\approx4σ$ significance. The integrated [CII] line emission is spatially offset about $\sim4$ kpc from the rest-frame ultraviolet (UV) emission. The total [CII] luminosity ($L_{\rm [CII]}=2.7\times10^8~L_{\odot}$) is consistent with the relation between [CII] luminosity and star formation rate (SFR) observed in nearby and high-$z$ star forming galaxies. More interestingly, the [CII] line is blueshifted with respect to the Ly$α$ line by $980\pm10$ km s$^{-1}$. If confirmed, this corresponds to the largest velocity offset reported to date between the Ly$α$ line and a non-resonant line at $z\gtrsim6$. According to trends observed in other high redshift galaxies, the large Ly$α$ velocity offset in GN-108036 is consistent with its low Ly$α$ equivalent width and high UV absolute magnitude. Based on Ly$α$ radiative transfer models of expanding shells, the large Ly$α$ velocity offset in GN-108036 could be interpreted as the presence of a large column density of hydrogen gas, and/or an outflow with a velocity of $v_{\rm out}\simΔv_{\rm Ly α}/2\sim500$ km s$^{-1}$. We also report the 3$σ$ detection of a potential galaxy companion located $\sim30$ kpc east of GN-108036, at a similar systemic velocity, and with no counterpart rest-frame UV emission.
