2014/01/01 by Federico Lelli, Marc Verheijen, Filippo Fraternali
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Baryon #Dark matter #Dwarf galaxy #Dwarf galaxy problem #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy rotation curve #Gravitational potential #Interacting galaxy #Physics #Star formation #Stellar, planetary, and galactic studies #Surface brightness #astro-ph.CO #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201322657
published as Lelli, F., Verheijen, M., & Fraternali, F. 2014, A&A, 566, A71 · Published on A&A (23 pages, 9 tables, 12 figures, plus an optical-HI atlas). Typos fixed
openalex publication_date 2014/04/29 · arxiv created 2014/06/19 · arxiv updated 2014/06/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We investigate the dynamics of starbursting dwarf galaxies, using both new and archival H I observations. We consider 18 nearby galaxies that have been resolved into single stars by HST observations, providing their star formation history and total stellar mass. We find that 9 objects have a regularly rotating H I disk, 7 have a kinematically disturbed H I disk, and 2 show unsettled H I distributions. Two galaxies (NGC 5253 and UGC 6456) show a velocity gradient along the minor axis of the H I disk, which we interpret as strong radial motions. For galaxies with a regularly rotating disk we derive rotation curves, while for galaxies with a kinematically disturbed disk, we estimate the rotation velocities in their outer parts. We derive baryonic fractions within about 3 optical scale lengths and find that, on average, baryons constitute at least 30% of the total mass. Despite the star formation having injected ~1056 ergs in the ISM in the past ~500 Myr, these starbursting dwarfs have both baryonic and gas fractions similar to those of typical dwarf irregulars, suggesting that they did not eject a large amount of gas out of their potential wells.