Bruce G. Elmegreen, Sangeeta Malhotra, et al.
ApJ
Hubble Space Telescope observations in 17, B, V, and I passbands of the interacting spiral galaxies IC 2163 and NGC 2207 are used to measure extinctions in the cloud and intercloud regions and ages and luminosities of the star-forming regions. The extinction in the part of NGC 2207 seen in projection against IC 2163 was determined by using the method of White & Keel. The extinctions there and elsewhere were also determined from radiative transfer models of the magnitude differences between clouds and their surroundings. The intercloud extinction in V band ranges from 0.5 to 1 mag on the line of sight, and the cloud extinction ranges from 1 to 2 mag. The measured star-forming regions in these galaxies have a power-law relation between size and luminosity and a power-law luminosity distribution function. These power laws are consistent with a fractal dimension for the star formation that is the same as that for interstellar gas, D ∼ 2.2, extending over scales ranging from 20 to 1000 pc. Fifteen compact massive star clusters that are analogous to super-star clusters found in starburst regions are in the spiral arms of NGC 2207. Nothing is peculiar about these regions except for a high H i velocity dispersion (∼50 km s-1). Two more super-star clusters are in the tidally compressed oval of IC 2163. These clusters have masses ranging from ∼ 104 to 2 × 105 M0 and ages of a few times 106 yr.
Bruce G. Elmegreen, Sangeeta Malhotra, et al.
ApJ
Deidre A. Hunter, Bruce G. Elmegreen, et al.
Astronomical Journal
Bruce G. Elmegreen, Susan M. Sanchez, et al.
WSC 2014
Elena Sacchi, Michele Cignoni, et al.
ApJ