Where do z~2 Submillimeter-Emitting Galaxies Lie On the Black-Hole-Spheroid Mass Plane?
D. M. Alexander
备注：
9 pages, 2 figures, to appear in the proceedings of "The Starburst-AGN Connection Conference", Shanghai, China, 27 Oct - 1 Nov 2008, ASP Conference Series
Submillimeter-emitting galaxies (SMGs) are z~2 bolometrically luminous systems hosting energetic starburst and AGN activity. SMGs may represent a rapid growth phase that every massive galaxy undergoes before lying on the well-established black-hole-spheroid mass relationship in the local Universe. Here we briefly discuss our recent results from Alexander et al. (2008) where we estimated the masses of the black holes in SMGs using the black-hole virial mass estimator, finding M_BH~6x10^7 M_solar for typical SMGs. We show that the black-hole-spheroid mass ratio for SMGs at z~2 was suggestively below that found for massive galaxies in the local Universe and more than an order of magnitude below the black-hole-spheroid mass ratio estimated for z~2 quasars and radio galaxies. We demonstrate that SMGs and their progeny cannot lie on the elevated z~2 black-hole-spheroid mass relationship of quasars-radio galaxies without overproducing the space density of the most massive black holes (M_BH~10^9 M_solar), unless the galaxy spheroid of SMGs is an order of magnitude lower than that typically assumed (M_SPH~10^10 M_solar). We also show that the relative black-hole-spheroid growth rates of typical SMGs appear to be insufficient to significantly increase the black-hole-spheroid mass ratio, without requiring long duty cycles (~10^9 years), and argue that a more AGN-dominated phase (e.g., an optically bright quasar) is required to significantly move SMGs (and their progeny) up the black-hole-spheroid mass plane.
The 30 Doradus Molecular Cloud at 0.4 pc Resolution with the Atacama Large Millimeter/submillimeter Array: Physical Properties and the Boundedness of CO-emitting Structures
我们提供了一个宽视场（约60 x 90 pc）的ALMA镶嵌的CO（2-1）和$^{13}$ CO（2-1）发射的分子云与剑鱼座30恒星形成区的结果。三个主要的发射复合体，包括两个形成一个蝴蝶结形的结构延伸东北和西南从中央R136集群，被分解成复杂的附属网络。与以前的研究一致，我们发现，云的中心区域具有较高的线宽在固定的大小相对于其余的分子云和其他LMC云，表明湍流运动的增强水平。然而，引力有界性（通过维里参数测量）与R136的距离没有明显的趋势。在$^{13}$ CO中观察到的结构在空间上与细丝一致，并且接近维里平衡状态。相比之下，CO结构在维里化中变化很大，主要的非束缚网络之外的低CO表面亮度结构占主导地位。低表面亮度的结构约占测量到的CO光度的10%;它们可能是先前恒星形成气体团的碎片残余物，或者是更大质量的CO-暗结构的CO发射部分。
FIR-luminous [CII] emitters in the ALMA-SCUBA-2 COSMOS survey (AS2COSMOS): The nature of submillimeter galaxies in a 10 comoving Mpc-scale structure at z~4.6
我们报告了一个10百万分之一秒尺度的结构跟踪的大质量亚毫米星系（SMG）在z~4.6。这些星系是从ALMA波段7观测的发射线搜索中选出的，目标是184个发光的亚毫米源（$S_{850μ{\rm m}}\geq$ 6.2 mJy），横跨1.6度$^2$在COSMOS领域。我们在z=4.60-4.64处识别出四个[CII]发射SMG和两个可能的[CII]发射SMG候选者，其中速度积分信噪比SNR>8。六个发射器中有四个是近红外空白SMG。在排除了一个SMG的发射线是在光谱窗口的边缘下降，所有的星系都显示出清晰的速度梯度沿主轴是一致的旋转气体盘。估计的磁盘的旋转速度为330-550公里秒$^{-1}$和推断的主机暗物质晕质量为~2-8 $\times$ 10 $^{12}$ M $_{\odot}$。从它们的晕质量和[CII]光度函数估计，我们认为，这些星系有一个高（50-100%）的占空比和高（~0.1）的重子转换效率（SFR相对于重子吸积率），它们的贡献$\simeq$ 2%的总恒星形成率密度在z=4.6。这些SMG仅集中在整个调查量的0.3%内，表明它们具有很强的集群性。这种结构的范围和单个晕质量表明，这些SMG可能会演变成一个约10 $^{15}$ M $_{\odot}$集群在z=0的成员。这项调查揭示了z>4的大质量晕中的同步尘埃星暴，这可能是由合并驱动的，也可能是由平滑的气…
Luminous Infrared Galaxies with the Submillimeter Array: II. Comparing the CO(3-2) Sizes and Luminosities of Local and High-Redshift Luminous Infrared Galaxies
