Complex distribution and velocity field of molecular gas in NGC 1316 as revealed by Morita Array of ALMA

摘要: We present the results of $^{12}$CO($J$=1-0) mosaicing observations cD galaxy NGC 1316 at kpc-resolution performed with Morita Array Atacama Large Millimeter/submillimeter (ALMA). reveal detailed distribution molecular gas in central region for first time: a shell structure northwest, barely resolved blob southeast center and some clumps between them. The total mass obtained standard Milky-Way CO-to-H$_2$ conversion factor is $(5.62 \pm 0.53)\times10^8$ M$_\odot$, which consistent previous studies. disturbed velocity field suggests that injected very recently ($<1$ Gyr) if it has an external origin process settling into rotating disk. Assuming low-mass gas-rich accreted, gas-to-dust ratio H$_2$-to-HI are unusually low ($\sim 28$) high 5.6$), respectively. To explain these ratios, additional processes should be taken accounts such as effective dust formation from atomic to during interaction. also discuss interaction nuclear jet gas.