The Kinematics of Blue Compact Galaxies - Gas and Stars
2006 (English)Licentiate thesis, monograph (Other scientific)
Blue Compact Galaxies (BCGs) are intensely star forming, gas-rich systems and their light is dominated by a young stellar population and nebular emission. Their irregular morphology suggests dwarf galaxy mergers as cause for the onset of the burst in star formation. We use interferometric measurements of the Doppler-shifted H-alpha line in emission to derive the kinematics of a medium sized sample of BCGs with high spatial resolution and coverage. In agreement with previous results, we find disturbed velocity fields in many cases, strengthening the merger hypothesis. In five cases we find the central starburst ionising large regions of the surrounding gas reservoir. After subtracting a model for the rotation of the ionised region, kinematical disturbances at the location of the starburst are revealed and we interpret them as decoupled motions or strong outflows due to feedback. To test whether feedback processes are able to decouple the interstellar medium from the motion of the stars, we use integral field spectroscopy of the near-infrared Ca-triplet to measure the stellar kinematics of BCGs. We find strong evidence for decoupling in Henize 2-10.
Place, publisher, year, edition, pages
Inst. f. astronomi o. rymdfysik, Uppsala universitet , 2006.
IdentifiersURN: urn:nbn:se:uu:diva-86508OAI: oai:DiVA.org:uu-86508DiVA: diva2:117318