2008/08/12 by David R. Andersen, C. Jakob Walcher, C. J. Walcher +7 · 30 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Center (category theory) #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy merger #Gamma-ray bursts and supernovae #Physics #Protogalaxy #Star cluster #Star formation #astro-ph
paper · pdf · doi:10.1086/592342
published in The Astrophysical Journal 688(2), 990-999 (IOP Publishing) · Accepted for publication in ApJ; 11 pages, 7 figures, Replaced figure 3 with correct version
arxiv created 2008/08/12 · openalex publication_date 2008/11/17 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Close to its center, the bulgeless galaxy NGC 2139 hosts a star cluster that is younger and less massive than any nuclear star cluster (NC) studied so far. We have measured the Hα velocity field around the photometric center of this galaxy using the VLT ARGUS integral field unit and the GIRAFFE spectrograph in order to constrain different proposed theories of NC formation. We observe that the best-fit kinematic center and the candidate NC appear to be separated by 2.8'' (320 pc). Indeed, the kinematic center is also offset from the galaxy's photometric center and a possible bar or extended region of star formation in which the young cluster resides, implying that this galaxy is not in dynamic equilibrium. The Hα flux map also reveals other regions of strong star formation in the possible bar. These observations suggest that a nascent NC is forming away from the kinematic center of NGC 2139, which may come to rest there on a timescale of a few 100 Myr.