Wide-field global VLBI and MERLIN combined monitoring of supernova
  remnants in M82
  From a combination of MERLIN (Multi-Element Radio-Linked Interferometer
Network) and global VLBI (Very Long Baseline Interferometry) observations of
the starburst galaxy M82, images of 36 discrete sources at resolutions ranging
from ~3 to ~80 mas at 1.7 GHz are presented. Of these 36 sources, 32 are
identified as supernova remnants, 2 are HII regions, and 3 remain unclassified.
Sizes, flux densities and radio brightnesses are given for all of the detected
sources. Additionally, global VLBI only data from this project are used to
image four of the most compact radio sources. These data provide a fifth epoch
of VLBI observations of these sources, covering a 19-yr time-line. In
particular, the continued expansion of one of the youngest supernova remnants,
43.31+59.3 is discussed. The deceleration parameter is a power-law index used
to represent the time evolution of the size of a supernova remnant. For the
source 43.31+59.3, a lower limit to the deceleration parameter is calculated to
be 0.53+/-0.06, based on a lower limit of the age of this source.
