本文系统的研究了星系整体的亚毫米波段水分子气体辐射。所有近邻星系的谱线数据来自于装载在 Herschel SPIRE 上的傅里叶变换光谱仪(FTS,覆盖波长从 194 到 672 微米)。所有的数据都是公开的。在总数为 176 个星系的样本中,我们探测到 45 个至少有一个 H2 O 转动能级跃迁辐射的星系。H2O 的光度介于 ～ 1 × 105 L⊙ 和 ～ 5 × 107 L⊙ 之间,而总红外光度(LIR )的范围为从 ～1 到 300 ×1010 L⊙。除此之外,我们还探测到了 H2O+和 H18 2 O 的谱线,发现 H2 O 是在 SPIRE/FTS 频段内仅次于高阶 CO 的最强分子辐射体。此外,星系的 H2O 发射线光度和 LIR 之间有很好的线性关系,这个关系不受强 AGN 存在与否的干扰。在我们探测到的 8 条谱线中 H2O(211-202 ) 和 H2O(220-211 ) 的光度随着总红外光度的增长略微高于线性。当把高红移的极亮红外星系(ULIRG,1011 ﹀

We report the first systematic study of the submillimeter water vapor rotational emission lines,in submillimeter regime in infrared (IR) galaxies based on the Fourier Transform Spectrometer(FTS) data of Herschel SPIRE (covering from 194 to 672 μ m). Among the 176 galaxies withpublicly available FTS data, 45 have at least one H2O emission line detected. The H2O line lu-minosities range from ～ 1 × 105 L⊙ to ～ 5 × 107 L⊙ while the total IR luminosities (LIR ) have asimilar spread (～1-300 ×1010 L⊙ ). Besides, the emission lines of H2O ionic and 18O isotope arealso detected. H2O is found, for most galaxies, to be the strongest molecular emitter after CO inFTS spectra. The luminosity of the five most important H2O lines is near-linearly correlated withLIR no matter strong AGN signature is present or not. However, the luminosity of H2 O(211 -202)and H2O(220-211 ) appears to increase slightly faster than linear with LIR . Although the slope turnsout to be slightly steeper when z～2-4 ULIRGs (Ultra-Luminous InfraRed Galaxies) are included,the correlation is still closely linear. We find that LH2 O/LIR decreases with increasing f25 /f60, butno dependence on f60 /f100, possibly indicating that very warm dust contributes little to the excita-tion of submillimeter H2 O lines. The average spectral line energy distribution (SLED) of entiresample is consistent with individual SLEDs and the IR pumping plus collisional excitation model,showing that the strongest lines are H2O(202-111 ) and H2 O(321 -312). Besides, we have detectedlow-lying H2 O lines in six high-z lensed ULIRGs (ultra-luminous infrared galaxies) that pickedfrom H-ATLAS survey. Their line profiles are similar to those of the high-J CO lines. By compar-ing the map of H2O and dust continuum emission, the emission from H2O is more compact thandust. A slightly faster than linear correlation has been found in these high-z ULIRGs.