Vol. 542
In section 1. Letters

Rapid variability of the compact radio sources in Arp220. Evidence for a population of microblazars?

The starburst galaxy Arp220 is a merger remnant, with two galaxy nuclei containing multiple compact radio sources previously identified as supernova remnants. During VLBI monitoring observations at 6 cm, the authors have discovered rapid ( 4c) of jet-like features near rapidly varying almost stationary components. The best interpretation for these enigmatic sources is that they are highly beamed microquasars (i.e. microblazars).