Fabry-perot Hα-interferometric observations of some HII regions. I. SH2-152 and SH2-153

H -interferometric observations of the HII-regions Sh2-152 and Sh2-153 are carried out with a high resolution (1 pixel=2.13×2.13 arcsec). They confirm the results on the structure of those formations obtained earlier. Individual radial velocities determined in different points for each of these HII-regions show that the inner motions of ionized matter relative to the exciting stars are, in general, of expanding character. It gives ground to assume that in both these star forming regions the dissipation of matter takes place.Published in Astrofizika, Vol. 37, No. 2, pp. 175–186, April–June, 1994.     

The velocity field of UGC 6697 revisited

The edge-on galaxy UGC 6697 has a peculiar morphological appearance: a high surface brightness SE component and what appears to be a tidal tail with blue color and low surface brightness extending toward the NW, as dramatically evidenced in subarcsecond broad band images taken with the VLT and in a deep Hα frame. Long-slit spectroscopy shows a 500 km/s rigid-body rotation curve with a sudden central velocity jump, of more than 200 km/s amplitude. Fabry-Perot observations of the Hα emission line enable us to trace a detailed 2D velocity field, confirming the complex kinematical behaviour, particularly in the circumnuclear region where multiple velocity components are clearly superposed on the same line of sight. This region hosts a double nucleus and shows sudden color and metallicity gradients, which can be reconciled with the complex velocity field assuming the presence of a second galaxy hidden behind the main body of UGC 6697. This revised version was published online in September 2006 with corrections to the Cover Date.