IMAGING ATOMIC AND HIGHLY EXCITED MOLECULAR GAS IN a z = 6.42 QUASAR HOST GALAXY: COPIOUS FUEL FOR AN EDDINGTON-LIMITED STARBURST AT THE END OF COSMIC REIONIZATION
IMAGING ATOMIC AND HIGHLY EXCITED MOLECULAR GAS IN a z = 6.42 QUASAR HOST GALAXY: COPIOUS FUEL FOR AN EDDINGTON-LIMITED STARBURST AT THE END OF COSMIC REIONIZATION
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DOI：
10.1088/0004-637x/703/2/1338
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发表时间：
2009-07
期刊：
影响因子：
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通讯作者：
D. Riechers;F. Walter;F. Bertoldi;C. Carilli;M. Aravena;R. Neri;P. Cox;A. Weiss;K. Menten
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文献类型：
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作者：
D. Riechers;F. Walter;F. Bertoldi;C. Carilli;M. Aravena;R. Neri;P. Cox;A. Weiss;K. Menten
我们利用Plateau de Bure干涉仪对z = 6.42的类星体SDSS J114816.64+525150.3（以下简称J1148+5251）的宿主星系进行了CO（J = 7 → 6）和Ci（3P2 → 3P1）辐射的观测。CO（J = 7 → 6）发射区具有空间分辨能力，其大小为5kpc，与早期的CO（J = 3 → 2）观测结果一致。结合该源中碰撞线激发的修订模型，这表明CO J = 7 → 6线追踪的高激发分子气体是亚热激发的（仅显示CO J = 3 → 2亮度的58% ± 8%），但不是更集中。我们还在主星系J1148+5251中探测到了Ci（3P2 → 3P1）辐射，但该谱线太微弱，无法进行可靠的大小测量。从C i（3P2 → 3P1）线通量，我们推导出总原子碳质量MC i = 1.1 ×107 M分，相当于总分子气体质量的1.5 × 10−4倍。我们还搜索了H2O（= 212 → 101）发射，并获得了4.4 × 109 K km s−1 pc 2的灵敏线光度极限，即，<CO（J = 3 → 2）光度的15%。在宇宙再电离结束时，这个类星体宿主中温暖的、高度激发的分子气体、原子气体和尘埃保持着强烈的星爆，其表面密度达到了爱丁顿有限星星形成千秒差距尺度（尘埃不透明度）所预测的那样高。
We have imaged CO(J = 7 → 6) and C i(3P2 → 3P1) emission in the host galaxy of the z = 6.42 quasar SDSS J114816.64+525150.3 (hereafter J1148+5251) through observations with the Plateau de Bure Interferometer. The region showing CO(J = 7 → 6) emission is spatially resolved, and its size of 5 kpc is in good agreement with earlier CO(J = 3 → 2) observations. In combination with a revised model of the collisional line excitation in this source, this indicates that the highly excited molecular gas traced by the CO J = 7 → 6 line is subthermally excited (showing only 58% ± 8% of the CO J = 3 → 2 luminosity), but not more centrally concentrated. We also detect C i(3P2 → 3P1) emission in the host galaxy of J1148+5251, but the line is too faint to enable a reliable size measurement. From the C i(3P2 → 3P1) line flux, we derive a total atomic carbon mass of MC i = 1.1 ×107 M☉, which corresponds to ∼5 × 10−4 times the total molecular gas mass. We also searched for H2O( = 212 → 101) emission, and obtained a sensitive line luminosity limit of 4.4 × 109 K km s−1 pc2, i.e., <15% of the CO(J = 3 → 2) luminosity. The warm, highly excited molecular gas, atomic gas and dust in this quasar host at the end of cosmic reionization maintain an intense starburst that reaches surface densities as high as predicted by (dust opacity) Eddington limited star formation over kiloparsec scales.