标题： 由核区棒驱动的巨分子内流供给的ESO 320-G030中的原伪核 显示英文标题

标题： A proto-pseudobulge in ESO 320-G030 fed by a massive molecular inflow driven by a nuclear bar

摘要： 具有核棒的星系被认为能够有效地将气体向内驱动，从而产生核区恒星爆发，并可能形成活动星系核 (AGN)。 我们基于赫歇尔和 ALMA 光谱观测分析，确认了这一情景适用于孤立的、双棒、亮红外星系 ESO 320-G030。 赫歇尔/PACS 和 SPIRE 对 ESO 320-G030 的观测显示了 18 条 H2O 谱线中的吸收/发射特征，我们将这些特征与 ALMA H2O 423-330 448 GHz 谱线（Eupper~400 K）和连续谱图像结合，研究其核区。 辐射传递模型表明，需要三个核区组分来解释 H2O 和连续谱数据。 一个半径约 130-150 pc、尘埃温度约 50 K、分子氢柱密度约 2×10^{23} cm^{-2}的包层，环绕着一个半径约 40 pc、τ_100um 约 1.5-3（N_H2~2×10^{24} cm^{-2}）的核盘以及一个极其紧凑（半径约 12 pc）、温暖（约 100 K）、埋藏（τ_100um>5，N_H2>~5×10^{24} cm^{-2}）的核心组分。 这三个核区组分占星系 L_IR 的 70%（SFR~16-18 Msun yr^{-1}）。 核区通过 ALMA 观测到的 CO 2-1 分子内流获得补充，该内流与核棒相关联。 随着半径减小（r=450-225 pc），质量吸积率增加到约20 M☉ yr{-1}，这与核区恒星形成率相当，表明爆发式恒星形成由吸积维持。 在较小的半径下，远红外OH基态双线最适合探测吸积，估计吸积率为~30 M☉ yr{-1}。 核区气体补充的时间尺度约为20 Myr，表明快速的准周期演化，并且我们正在见证一个由强大核棒驱动的大规模吸积所供给的原伪球状结构的中间阶段（<100 Myr）。 我们还应用H2O模型来分析赫歇尔望远镜的H2^{18}O、OH、^{18}OH、OH+、H2O+、H3O+、NH、NH2、NH3、CH、CH+、^{13}CH+、HF、SH和C3的远红外光谱观测数据，并估算它们的丰度。 显示英文摘要

摘要： Galaxies with nuclear bars are believed to efficiently drive gas inward, generating a nuclear starburst and possibly an active galactic nucleus (AGN). We confirm this scenario for the isolated, double-barred, luminous infrared galaxy ESO 320-G030 based on an analysis of Herschel and ALMA spectroscopic observations. Herschel/PACS and SPIRE observations of ESO 320-G030 show absorption/emission in 18 lines of H2O, which we combine with the ALMA H2O 423-330 448 GHz line (Eupper~400 K) and continuum images to study the nuclear region. Radiative transfer models indicate that 3 nuclear components are required to account for the H2O and continuum data. An envelope, with R~130-150 pc, T_dust~50 K, and N_H2~2x10^{23} cm^{-2}, surrounds a nuclear disk with R~40 pc and tau_100um~1.5-3 (N_H2~2x10^{24} cm^{-2}) and an extremely compact (R~12 pc), warm (~100 K), and buried (tau_100um>5, N_H2>~5x10^{24} cm^{-2}) core component. The three nuclear components account for 70% of the galaxy L_IR (SFR~16-18 Msun yr^{-1}). The nucleus is fed by a molecular inflow observed in CO 2-1 with ALMA, which is associated with the nuclear bar. With decreasing radius (r=450-225 pc), the mass inflow rate increases up to ~20 Msun yr^{-1}, which is similar to the nuclear SFR, indicating that the starburst is sustained by the inflow. At lower r, the inflow is best probed by the far-infrared OH ground-state doublets, with an estimated inflow rate of ~30 Msun yr^{-1}. The short timescale of ~20 Myr for nuclear gas replenishment indicates quick secular evolution, and indicates that we are witnessing an intermediate stage (<100 Myr) proto-pseudobulge fed by a massive inflow that is driven by a strong nuclear bar. We also apply the H2O model to the Herschel far-infrared spectroscopic observations of H2^{18}O, OH, $^{18}OH, OH+, H2O^+, H3O^+, NH, NH2, NH3, CH, CH^+, ^{13}CH^+, HF, SH, and C3, and estimate their abundances.