Properties of molecular gas in galaxies in early and mid stages of Interaction. III. Resolved Kennicutt?Schmidt law
Properties of molecular gas in galaxies in early and mid stages of Interaction. III. Resolved Kennicutt?Schmidt law
复制标题
相互作用早期和中期星系中分子气体的性质。
DOI：
10.1093/pasj/psab129
复制
发表时间：
2022
影响因子：
2.3
通讯作者：
Sawada Tsuyoshi
中科院分区：
文献类型：
--
作者：
Kaneko Hiroyuki;Kuno Nario;Iono Daisuke;Tamura Yoichi;Tosaki Tomoka;Nakanishi Kouichiro;Sawada Tsuyoshi
我们研究了星际介质的性质，恒星的成分，和恒星形成活动，在相互作用的早期和中期的四个邻近星系对在星系尺度和kpc尺度。星系尺度的kennicut - schmidt定律表明，与孤立星系的最佳拟合相比，8个相互作用星系中有7个的恒星形成率在3倍之内，尽管我们在之前的论文中已经表明，在相互作用期间，分子氢气是有效地从原子氢中产生的（Kaneko等人）。Pasj, 69,66)。相互作用星系的星系尺度特定恒星形成速率（sSFR）和恒星形成效率（SFE）与孤立星系相当。我们还在kpc尺度上研究了SFE和kennicut - schmidt定律。SFE的空间分布表明，SFE是局部增强的，增强区域不对称或在非中心区域。休克可引起SFE的局部增强。我们发现相互作用星系早期的kennicut - schmidt定律指数为1.30±0.04，与孤立星系的指数一致。由于kennicut - schmidt定律中使用的CO排放是分子气体数量的示色剂，这一事实表明，与恒星形成更直接相关的致密气体在相互作用的早期阶段没有改变。
We study properties of the interstellar medium, an ingredient of stars, and star formation activity, in four nearby galaxy pairs in the early and mid stages of interaction for both a galaxy scale and a kpc scale. The galaxy-scale Kennicutt–Schmidt law shows that seven of eight interacting galaxies have a star formation rate within a factor of three compared with the best fit of the isolated galaxies, although we have shown that molecular hydrogen gas is efficiently produced from atomic hydrogen during the interaction in the previous paper (Kaneko et al. PASJ, 69, 66). The galaxy-scale specific star formation rate (sSFR) and star formation efficiency (SFE) in interacting galaxies are comparable to those in isolated galaxies. We also investigate SFE and the Kennicutt–Schmidt law on a kpc scale. The spatial distributions of SFE reveal that SFE is locally enhanced, and the enhanced regions take place asymmetrically or at off-centre regions. The local enhancement of SFE could be induced by shock. We find that the index of the Kennicutt–Schmidt law for the interacting galaxies in the early stage is 1.30 ± 0.04, which is consistent with that of the isolated galaxies. Since CO emission, which is used in the Kennicutt–Schmidt law, is a tracer of the amount of molecular gas, this fact suggests that dense gas, which is more directly connected to star formation, is not changed at the early stage of interaction.