-
High-Resolution Radio Observations of Supernova SN 1993J,
M.A. Pérez-Torres, A. Alberdi, J.C. Guirado, J.M. Marcaide,
L. Lara, F. Mantovani, E. Ros, & K.W. Weiler;
Highlights in Spanish Astrophysics (III), Proceedings
of the V Scientific Meeting of the Spanish Astronomical Society,
J. Gallego, J. Zamorano, N. Cardiel (eds.),
Kluwer Academic Publishers,
325-328 (2003)
- Abstract
We present high-resolution observations of the supernova SN 1986J
in the galaxy NGC 891 at the frequency of 5 GHz, more than
15 years after its explosion. The image shows a highly distorted shell of radio emission, suggesting that the shock front has been strongly deformed. The
brightness distribution within the shell is also highly asymmetric, and we propoese that such asymmetry could be due to the collision of the supernova ejecta with an anisotropic, clumpy medium. The average speed of the shell has decreased from about 7400 km s-1 in 1998.74 down to
~6300 km s-1 in 1999.14, pionting to a mild
deceleration in the expansion of SN 1986J. Assuming a standard
density profile for the progenitor wind, we infer a swept-up mass
by the shock front of ~2.2 Msun. Since the supernova has not yet
suffered a strong deceleration, momentum conservation arguments point to a mass of the
hydrogen-rich envelope ejected at explosion as large as ~12 Msun.
Eduardo Ros
