An Estimate of the Gas Inflow Rate Along the Bar in NGC 7479

摘要

We present images of the barred galaxy NGC 7479 in the optical and nearinfrared broad--bands $B,V,R,J,H,K$, and images in H$lpha$+[N II] andCO(J=1$ightarrow$0) emission. The H$lpha$ and CO emission in the bar arecoincident and confined to narrow linear features that are offset from thecenter of the bar as observed in the near infrared. We estimate thegravitational potential from the $K$ image, which provides an estimate of thetorque on the gas at the position of the CO emission in the bar. We find thatthe implied gas inflow velocity derived from the torque is $10-20$ km s$^{-1}$.Our inflow velocity is independent of the large streaming motions which can beobserved in CO and HI.