2008/06/23 by C. Gallart, Carme Gallart, Peter B. Stetson +7 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Large Magellanic Cloud #Population #RADIUS #Spiral galaxy #Star formation #Stellar density #Stellar evolution #Stellar population #astro-ph
paper · pdf · doi:10.1086/590552
6 pages, 2 figures, ApJ Letters, in press
arxiv created 2008/06/23 · openalex publication_date 2008/07/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
From the analysis of the color-magnitude diagrams and color functions of four wide LMC fields located from ≃2 to 6 kpc from the kinematic center of the LMC we present evidence that, while the oldest population is coeval in all fields, the age of the youngest component of the dominant stellar population gradually increases with galactocentric distance, from currently active star formation in a field at 2.3°, to 100 Myr, 0.8 Gyr, and 1.5 Gyr in fields at 4.0°, 5.5°, and 7.1°, respectively. This outside-in quenching of the star formation in the LMC disk is correlated with the decreasing H I column density (which is ≤2 × 10 20 cm −2 in the two outermost fields with little or no current star formation). Other work in the literature hints at similar behavior in the stellar populations of irregular galaxies and in M33. This is observational evidence against the inside-out disk formation scenario in low-mass spirals and irregular galaxies. Alternatively, it could be that the age distribution with radius results from interplay between the evolution with time of the star-forming area of the LMC and the subsequent outward migration of the stars.