1998/01/27 by E. Battaner, Battaner, E., E. Florido +4
Physics and Astronomy · #Astro and Planetary Science #Astrophysics (astro-ph) #Astrophysics and Star Formation Studies #FOS: Physical sciences #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9801263
10 pages, 5 figures, LaTeX using A&A macros v4.. Also available as gzipped postscript at http://deneb.ugr.es/papers/trunky.ps.gz
arxiv created 1998/01/27 · openalex publication_date 1998/01/27 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The truncation of stellar discs is not abrupt but characterized by a continuous distancing from the exponential profile. There exists a truncation curve, t(r), ending at a truncation radius, rt. We present here a theoretical model in which it is assumed that the magnetic hypothesis explaining the flat rotation curve also explains the truncation. Once stars are born, the centripetal magnetic force previously acting on the progenitor gas cloud is suddenly interrupted, and stars must move to larger orbits or escape. The agreement between theoretical and observed truncation curves is very satisfactory. Parameters defining the disc gas rotation curve should therefore be related to those defining the truncation. It is predicted that rotation curves that quickly reach the asymptotic value θ0 = θ(r=∞) would have small truncation radii. On the contrary, rt and θ0 itself, would be uncorrelated quantities.