论文标题
部分可观测时空混沌系统的无模型预测
Extreme giant molecular clouds in the luminous infrared galaxy NGC 3256
论文作者
论文摘要
（删节）我们提出了$^{12} $ co（2--1）合并和最近发光的红外星系的观察，NGC3256。185在空间和光谱上解决的云层均在90 kpc $^{2} $^$^{2} $^$^{2} $上确定了90 pc anditess Issolution and Lesite anditess Issolutions估算。我们将云目录从NGC 3256与Phangs-Alma调查中观察到的十个星系进行了比较。 NGC 3256中的分布云速度分散剂，亮度，共估计的质量，质量表面密度，病毒式质量，病毒式参数，尺寸线宽系数和内部湍流压力明显高于phangs-alma星系。 NGC 3256中的云半径略大，自由下落时间较短。 NGC 3256中云偏心率的分布与许多phangs-alma星系没有区别，这可能是因为NGC 3256中云的动态状态与附近的螺旋星系相似。但是，NGC 3256中病毒参数的分布较窄，可能反映出动态状态的范围要比phangs-alma星系中的范围更窄。尽管偏心率很高，但仍未检测到云对齐的清晰图像。云特性之间的相关性指向NGC 3256中的高外部压力，鉴于如此高的速度分散率和恒星形成速率，保持云的绑定和崩溃。拟合云质量函数的高质量功率坡度为$ -2.75^{+0.07} _ { - 0.01} $，接近来自phangs-Alma星系的平均值。我们还将结果与基于像素的观测值的分析进行了比较，并发现分子气体特性在定性上一致，尽管峰值亮度温度在此基于云的分析中较高，并且病毒式参数较高，而自由下落的时间则较低。
(Abridged) We present a cloud decomposition of $^{12}$CO (2--1) observations of the merger and nearest luminous infrared galaxy, NGC 3256. 185 spatially and spectrally resolved clouds are identified across the central $\approx$ 130 kpc$^{2}$ at 90 pc resolution and completeness is estimated. We compare our cloud catalogue from NGC 3256 to ten galaxies observed in the PHANGS-ALMA survey. Distributions in NGC 3256 of cloud velocity dispersions, luminosities, CO-estimated masses, mass surface densities, virial masses, virial parameters, size-linewidth coefficients, and internal turbulent pressures are significantly higher than in the PHANGS-ALMA galaxies. Cloud radii are slightly larger in NGC 3256 and free-fall times are shorter. The distribution of cloud eccentricities in NGC 3256 is indistinguishable from many PHANGS-ALMA galaxies, possibly because the dynamical state of clouds in NGC 3256 is similar to that of nearby spiral galaxies. However, the narrower distribution of virial parameters in NGC 3256 may reflect a narrower range of dynamical states than in PHANGS-ALMA galaxies. No clear picture of cloud alignment is detected, despite the large eccentricities. Correlations between cloud properties point to high external pressures in NGC 3256 keeping clouds bound and collapsing given such high velocity dispersions and star-formation rates. A fit to the cloud mass function gives a high-mass power-law slope of $-2.75^{+0.07}_{-0.01}$, near the average from PHANGS-ALMA galaxies. We also compare our results to a pixel-based analysis of these observations and find molecular-gas properties agree qualitatively, though peak brightness temperatures are somewhat higher and virial parameters and free-fall times are somewhat lower in this cloud-based analysis.
