DOI:
10.1051/0004-6361:20011794
Authors:
Marcaide, JM; Perez-Torres, MA; Ros, E; Alberdi, A; Diamond, PJ; Guirado, JC; Lara, L; Van Dyk, SD; Weiler, KW
Abstract:
We observed SN1979C in M100 on 4 June 1999, about twenty years after explosion, with a very sensitive four-antenna VLBI array at the wavelength of lambda18 cm. The distance to M100 and the expansion velocities are such that the supernova cannot be fully resolved by our Earth-wide array. Model-dependent sizes for the source have been determined and compared with previous results. We conclude that the supernova shock was initially in free expansion for 6 +/- 2 yrs and then experienced a very strong deceleration. The onset of deceleration took place a few years before the abrupt trend change in the integrated radio flux density curves. We estimate the shocked swept-up mass to be M-sw similar to 1.6 M-circle dot, assuming a standard density profile for the CSM. Such a swept-up mass for SN1979C suggests a mass of the hydrogen-rich envelope ejected at explosion no larger than M-env similar to 0.9 M-circle dot. If SN1979C originated in a binary star, the low value of Menv suggests that the companion of the progenitor star stripped off most of the hydrogen-rich envelope mass of the presupernova star prior to the explosion.
URL:
https://ui.adsabs.harvard.edu/#abs/2002A&A...384..408M/abstract
Keywords:
techniques : interferometric; supernovae : individual : SN1979C; ISM : supernova remnants; radio continuum : stars; galaxies : individual : M100