论文标题
CO激发及其与NGC 1365中200 PC的恒星形成的连接
CO Excitation and its Connection to Star Formation at 200 pc in NGC 1365
论文作者
论文摘要
我们报告了附近中部区域的高分辨率2“ 〜200 PC映射，禁止在CO（1--0）和CO（2---1）发射线中的螺旋星系NGC 1365。综合强度的2--1/1---0比率（2--1/1---0）比例显示了一个较大的散射（0.15），并发现了0.67的中位数和限定级别的比率分散率和velocition velocitio and velocition and velocition of velocition and velocition contio and velocities colocity and velocition in Colocities conemition and colocition and colocity ance colocities consection和速度分散比接近统一，因此峰值温度比与综合强度比相当，表明CO（1--0）和CO（2--1）线的分子气体的相似组成部分，其综合强度（或峰值）与最近的kp级级别相似。灭绝的H-alpha图表明，与最近的恒星形成相关的分子气体是密度和/或温暖的，我们还发现某些CO光谱由于运动的复杂而显示了两个峰，并且这两个成分可能在不同条件下表现出痕量分子在不同的条件下的质量效果。
We report high resolution 2" ~ 200 pc mappings of the central region of the nearby barred spiral galaxy NGC 1365 in the CO(1--0) and CO(2--1) emission lines. The 2--1/1--0 ratio of integrated intensities shows a large scatter (0.15) with a median value of 0.67. We also calculate the ratio of velocity dispersions and peak temperatures and find that in most cases the velocity dispersion ratio is close to unity and thus the peak temperature ratio is comparable to the integrated intensity ratio. This result indicates that both CO(1--0) and CO(2--1) lines trace similar components of molecular gas, with their integrated intensity (or peak temperature) ratios reflecting the gas density and/or temperature. Similar to recent kpc scale studies, these ratios show a positive correlation with a star formation rate indicator (here we use an extinction-corrected H-alpha map), suggesting that molecular gas associated with recent star formation is denser and/or warmer. We also find that some CO spectra show two peaks owing to complicated kinematics, and such two components likely trace molecular gas at different conditions. This result demonstrates the importance of spectral fitting to measure integrated intensities and their ratios more accurately.
