Molecular gas and star formation in BIMA SONG bars
  Using a sample of 7 barred spirals from the BIMA Survey of Nearby Galaxies (SONG), we compare the molecular gas distribution in the bar, to recent massive star formation activity. In all 7 galaxies, Halpha is offset azimuthally from the CO on the downstream side. The maximum offset, at the bar ends, ranges from 170-570 pc, with an average of 320 +/- 120 pc. We discuss whether the observed offsets are consistent with the description of gas flows in bars provided by the two main classes of models: n-body models and hydrodynamic models. This work is supported by NSF grants AST 9981289, AST 9981308. 
Kartik Sheth, Stuart N. Vogel, Andrew I. Harris (U. Maryland), Michael   W. Regan (StScI), Michele D. Thornley (NRAO), Tamar...