标题： 星际介质中的超新星率-速度弥散关系 显示英文标题

标题： The supernova rate-velocity dispersion relation in the interstellar medium

摘要： 我们研究了气体速度弥散与星际介质（ISM）中的超新星率和反馈效率之间的关系。 我们探索了星系盘外侧部分速度弥散剖面的恒定性，约为6-8 km s^-1，并研究了向星暴阶段的过渡现象。 我们的结果显示：a) 超新星驱动导致总气体的速度弥散接近常数，sig~6 km s^-1，而HI气体的速度弥散sigHI~3 km s^-1，且与超新星率无关，对于银河系超新星率R_{G}的0.01-0.5倍之间；b) 模拟中观测到的向星暴阶段过渡的位置SFR/Area~5*10^-3-10^-2 M_sol yr^-1 kpc^-2，与实际观测结果吻合良好；c) 对于高超新星率，模拟箱中没有HI气体存在，但总气体速度弥散模型与观测结果一致；d) 对于中间超新星率R/R_{G}~0.5-1，考虑HI线的热展宽有助于模型与观测结果在该区域达到良好一致性；e) 对于R/R_{G}<0.5，sig和sigHI低于观测值约2倍。 然而，不同反馈效率epsilon的一组模拟表明，对于更大的超新星反馈效率，可以得到接近5-6 km s^{-1}的HI气体速度弥散，与观测结果更为一致。 事实证明，当R/R_{G}<0.5时，HI气体速度弥散比观测值小约2倍，可能是因为低估了超新星反馈效率。 这也可能是其他物理过程与恒星反馈耦合以产生星系盘湍流水平的指示信号。 显示英文摘要

摘要： We investigate the relationship between the velocity dispersion of the gas and the SN rate and feedback efficiency in the ISM. We explore the constancy of the velocity dispersion profiles in the outer parts of galactic disks at~6-8 km s^-1, and the transition to the starburst regime. Our results show that a) SN driving leads to constant velocity dispersions of sig~6 km s^-1 for the total gas and sigHI~3 km s^-1 for the HI gas, independent of the SN rate, for values of the rate between 0.01-0.5 the Galactic rate R_{G},b) the position of the transition to the starburst regime at SFR/Area~5*10^-3-10^-2 M_sol yr^-1 kpc^-2 observed in the simulations, is in good agreement with the transition to the starburst regime in the observations, c) for the high SN rates, no HI gas is present in the simulations box, however, for the total gas velocity dispersion, there is good agreement between the models and the observations,d) at the intermediate SN rates R/R_{G}~0.5-1, taking into account the thermal broadening of the HI line helps reach a good agreement in that regime between the models and the observations,e) for R/R_{G}<0.5, sig and sigHI fall below the observed values by a factor of~2. However, a set of simulation with different values of epsilon indicates that for larger values of the supernova feedback efficiencies, velocity dispersions of the HI gas of the order of 5-6 km s^{-1} can be obtained, in closer agreement with the observations. The fact that for R/R_{G}<0.5, the HI gas velocity dispersions are a factor ~2 smaller than the observed values could result from the fact that we might have underestimated the SN feedback efficiency. It might also be an indication that other physical processes couple to the stellar feedback in order to produce the observed level of turbulence in galactic disks.