SMM J04135 +10277：z=2.8时两大星系早期“干湿”合并的候选者
SMM J04135+10277: A Candidate Early-Stage "Wet-Dry" Merger of Two Massive Galaxies at z=2.8
摘要：
我们报告的CO（J=3-2）的发射朝向z=2.846亚毫米选定的星系SMM J 04135 +10277，使用毫米波天文学研究组合阵列（CARMA）的干涉成像。SMM J 04135 +10277以前被认为是一个富含气体的亚毫米级类星体，在文献报道的高z类星体中具有最高的分子气体质量。相对于早期观测，我们的地图在~6x处提高了线性分辨率，空间分辨率为~1.7”尺度，对应于~5.2 kpc的（透镜校正）源半径。他们还揭示了分子气体库，因此，可能是亚毫米辐射，与类星体的宿主星系无关，而是与一个光学暗淡的富含气体的星系有关，该星系距离活动星系核（AGN）5.2”，或41.5 kpc的投影距离。这个被遮蔽的富气星系的动力学质量为M_dyn sin 2（i）=5.6x10^11 M_sun，相当于气体质量分数约为21%。假设z>2的类星体具有典型的M_BH/M* 比，则该系统中的两个星系的质量比约为1.9。我们的研究结果表明，这类星体星暴星系对可能代表了一个罕见的主要，富气/贫气（“湿干”）合并的两个大质量星系在z=2.8的早期阶段，而不是一个单一的，富含气体的活动星系核宿主星系。这样的系统可能在今天的大质量星系的早期积累中发挥重要作用，通过亚毫米发光的星暴阶段，并且可能在低和高红移的静止帧远红外选择类星体样本中隐藏大量。
英文摘要：
We report interferometric imaging of CO(J=3-2) emission toward the z=2.846 submillimeter-selected galaxy SMM J04135+10277, using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). SMM J04135+10277 was previously thought to be a gas-rich, submillimeter-selected quasar, with the highest molecular gas mass among high-z quasars reported in the literature. Our maps at ~6x improved linear resolution relative to earlier observations spatially resolve the emission on ~1.7" scales, corresponding to a (lensing-corrected) source radius of ~5.2 kpc. They also reveal that the molecular gas reservoir, and thus, likely the submillimeter emission, is not associated with the host galaxy of the quasar, but with an optically faint gas-rich galaxy at 5.2", or 41.5 kpc projected distance from the active galactic nucleus (AGN). The obscured gas-rich galaxy has a dynamical mass of M_dyn sin2(i)=5.6x10^11 M_sun, corresponding to a gas mass fraction of ~21%. Assuming a typical M_BH/M* ratio for z>2 quasars, the two galaxies in this system have an approximate mass ratio of ~1.9. Our findings suggest that this quasar-starburst galaxy pair could represent an early stage of a rare major, gas-rich/gas-poor ("wet-dry") merger of two massive galaxies at z=2.8, rather than a single, gas-rich AGN host galaxy. Such systems could play an important role in the early buildup of present-day massive galaxies through a submillimeter-luminous starburst phase, and may remain hidden in larger numbers among rest-frame far-infrared-selected quasar samples at low and high redshift.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
