1995/05/11 by Dennis Zaritsky · 1 citation
Physics and Astronomy · #Galaxies: Formation, Evolution, Phenomena #Gamma-ray bursts and supernovae #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/309586
published as Astrophys.J. 448 (1995) L17 · 4 pages (one Table and one Figure included). Accepted for Publication in ApJ Letters
arxiv created 1995/05/11 · openalex publication_date 1995/07/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
I discuss observations of magnitude residuals from the B -band Tully-Fisher relationship, B - V color, chemical abundance gradients, and asymmetries in the H I and stellar disks of nearby spiral galaxies within the context of a model in which small satellites or H I clouds are accreted onto the outer disks of spiral galaxies. Correlations between the various observables support the hypothesis that accretion dilutes the gas-phase abundances in the outer disk, steepens the abundance gradient across the disk, increases the star formation rate, and creates asymmetries in the outer disk. By estimating the duration of steep abundance gradients, elevated rates of star formation, or outer disk asymmetries, we can place constraints on the rate of accretion events. The data suggest that accretion events at the current time are common.