论文标题
阿尔玛（Alma
ALMA resolves the first strongly-lensed Optical/NIR-dark galaxy
论文作者
论文摘要
We present high-resolution ($\lesssim0.1$arcsec) ALMA observations of the strongly-lensed galaxy HATLASJ113526.2-01460 at redshift $z\sim3.1$ discovered in the Gama 12$^{\rm th}$ field of the Herschel-ATLAS survey.重力镜头系统非常奇特，因为背景源和前景镜头都没有显示出明确检测到的光学/NIR发射。我们在三个不同的（亚）MM连续频段以及C [ii]和CO（8-7）光谱线中执行准确的透镜建模和源形态重建。该建模表示带有质量$ $ \ gtrsim10^{11} \，m_ \ odot $ at $ z \ gtrsim1.5 $的前景镜头（可能椭圆形）星系，而源（sub-）mm continuum和线排放量被因子$μ\ sim6-13-13 $放大。我们估计，星形区域的极度紧凑尺寸$ \ lyssim0.5 $ kpc和$ \ lyssim 1 $ kpc的气体组件，没有明确的旋转证据或正在进行的合并事件。我们执行宽带SED拟合并检索源的固有脱磁物理特性，该物理特性具有很高的星形构型$ \ gtrsim10^3 \，M_ \ odot $ yr $ yr $^{ - 1} $，鉴于compact尺寸在edgington lime of Eddington for Starbursts的范围内；来自可用EVLA观测值的6 cm处的无线电发光度与恒星形成活性一致。发现星系非常丰富，$ \ sim10^{11} \，m_ \ odot $和dust $ \ gtrsim10^9 \，m_ \ odot $。恒星内容$ \ lyssim10^{11} \，m_ \ odot $将源远远超过星形星系的主要顺序，表明Starburst相当年轻，估计年龄$ \ sim10^8 $ yr。我们的结果表明，HATLASJ113526.2-01460的总体特性始终由原地星系形成和进化场景来解释。
We present high-resolution ($\lesssim0.1$arcsec) ALMA observations of the strongly-lensed galaxy HATLASJ113526.2-01460 at redshift $z\sim3.1$ discovered in the Gama 12$^{\rm th}$ field of the Herschel-ATLAS survey. The gravitationally lensed system is remarkably peculiar in that neither the background source nor the foreground lens show a clearly detected optical/NIR emission. We perform accurate lens modeling and source morphology reconstruction in three different (sub-)mm continuum bands, and in the C[II] and CO(8-7) spectral lines. The modeling indicates a foreground lensing (likely elliptical) galaxy with mass $\gtrsim10^{11}\, M_\odot$ at $z\gtrsim1.5$, while the source (sub-)mm continuum and line emissions are amplified by factors $μ\sim6-13$. We estimate extremely compact sizes $\lesssim0.5$ kpc for the star-forming region and $\lesssim 1$ kpc for the gas component, with no clear evidence of rotation or of ongoing merging events. We perform broadband SED-fitting and retrieve the intrinsic de-magnified physical properties of the source, which is found to feature a very high star-formation rate $\gtrsim10^3\, M_\odot$ yr$^{-1}$, that given the compact sizes is on the verge of the Eddington limit for starbursts; the radio luminosity at 6 cm from available EVLA observations is consistent with the star-formation activity. The galaxy is found to be extremely rich in gas $\sim10^{11}\, M_\odot$ and dust $\gtrsim10^9\, M_\odot$. The stellar content $\lesssim10^{11}\, M_\odot$ places the source well above the main sequence of starforming galaxies, indicating that the starburst is rather young with estimated age $\sim10^8$ yr. Our results indicate that the overall properties of HATLASJ113526.2-01460 are consistently explained by in-situ galaxy formation and evolution scenarios.
