Resolving Star Formation on Subkiloparsec Scales in the High-redshift Galaxy SDP.11 Using Gravitational Lensing
Resolving Star Formation on Subkiloparsec Scales in the High-redshift Galaxy SDP.11 Using Gravitational Lensing
复制标题
DOI：
10.3847/1538-4357/aae394
复制
发表时间：
2018-09
期刊：
影响因子：
--
通讯作者：
C. Lamarche;A. Verma;A. Vishwas;G. Stacey;D. Brisbin;C. Ferkinhoff;T. Nikola;S. Higdon;J. Higdon;M. Tecza
中科院分区：
文献类型：
--
作者：
C. Lamarche;A. Verma;A. Vishwas;G. Stacey;D. Brisbin;C. Ferkinhoff;T. Nikola;S. Higdon;J. Higdon;M. Tecza
我们利用新的赫歇尔和阿塔卡马大型毫米/亚毫米阵列（ALMA）对碳、氧和氮的远红外精细结构线的观测，研究了强透镜恒星形成星系H-ATLAS J091043.1-000321 （SDP.11）的星际介质、恒星形成和当前恒星种群的性质。我们报道了来自Herschel/PACS的[O iii] 52 μm， [N iii] 57 μm和[O i] 63 μm谱线的检测，并利用ALMA对[C ii] 158 μm谱线及其底层连续体进行了高分辨率成像。我们将[C ii]线发射分解成两个空间偏移的爱因斯坦环，在ALMA/波段9观测中追踪线的红色和蓝色速度分量。“2决议。在[C ii]/远红外（FIR）比值图中看到的值，在尘埃连续体的峰值低至~ 0.02%，与当地ulrgs的值相似，表明该源存在强烈的星暴。这与从紫外辐射场硬度估计的上次星暴事件以来的高固有FIR光度（~ 3 × 1012 L⊙）、~ 16 Myr气体耗尽时间标度和~ 8 Myr时间标度相一致。通过将引力透镜模型应用于紫外平面的可见性，我们发现透镜放大系数在SDP.11上以2倍的倍数变化，从而影响观测到的线轮廓。在校正了差透镜效应后，恢复了对称的线条轮廓，这表明这里出现的星暴可能不是主要合并的结果，就像本地ulrgs的情况一样，而是由分布在3 - 5kpc旋转盘上的恒星形成活动提供动力。
We investigate the properties of the interstellar medium, star formation, and the current-day stellar population in the strongly lensed star-forming galaxy H-ATLAS J091043.1-000321 (SDP.11), at z = 1.7830, using new Herschel and Atacama Large Millimeter/submillimeter Array (ALMA) observations of far-infrared fine-structure lines of carbon, oxygen, and nitrogen. We report detections of the [O iii] 52 μm, [N iii] 57 μm, and [O i] 63 μm lines from Herschel/PACS, and present high-resolution imaging of the [C ii] 158 μm line, and underlying continuum, using ALMA. We resolve the [C ii] line emission into two spatially offset Einstein rings, tracing the red and blue velocity components of the line, in the ALMA/Band 9 observations at 0.″2 resolution. The values seen in the [C ii]/far-infrared (FIR) ratio map, as low as ∼0.02% at the peak of the dust continuum, are similar to those of local ULIRGs, suggesting an intense starburst in this source. This is consistent with the high intrinsic FIR luminosity (∼3 × 1012 L⊙), ∼16 Myr gas depletion timescale, and ≲8 Myr timescale since the last starburst episode, estimated from the hardness of the UV radiation field. By applying gravitational lensing models to the visibilities in the uv-plane, we find that the lensing magnification factor varies by a factor of two across SDP.11, affecting the observed line profiles. After correcting for the effects of differential lensing, a symmetric line profile is recovered, suggesting that the starburst present here may not be the result of a major merger, as is the case for local ULIRGs, but instead could be powered by star formation activity spread across a 3–5 kpc rotating disk.