Galactic and extragalactic compact objects

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We will investigate extremely compact sources such as supernovae (SNe) and the environment of supermassive black holes in the center of galaxies and quasars. We will use the new EVLA and ALMA telescopes and the radio technique of very-long baseline interferometry (VLBI) to reveal details of the physical processes that otherwise would remain hidden. The latter technique, first used in Canada, allows us to zoom into compact radio sources and make images with a resolution 10,000 times better than that with the Hubble Space Telescope. In particular we will probe massive core-collapse SNe of type II and Ib/c, some of the latter related to gamma-ray bursts, the most powerful single events in the universe after the Big Bang. We will make movies of the expanding debris of the aftermath of the explosion. With hydrodynamic simulations we will probe in detail the physical parameters that shape the interaction of the expanding SN shock front with the circumstellar medium left over from the progenitor star. The shock front sweeping up the surrounding clouds of gas is like a time machine that records in a few years, in reverse, the history of the surface activity of the progenitor star thousands of years before it exploded. We will also search for any signs of a pulsar or a black hole as the central stellar corpse left over from the explosion. We will use the expanding shock-front method (ESL) developed by us to determine geometrically the distance to a SN and its host galaxy with a better than 10% uncertainty. SN 1979C in the Virgo cluster of galaxies is a candidate for which such well determined distance could also lead to a new determination of the Hubble constant with an uncertainty that is comparable to that of other methods. Any such new determination is useful since it could help to shed light on such fundamental cosmological questions as the degree of the spatial flatness of the universe, characteristics of the vacuum energy, and dark matter. We will also search for the jet in the nearby spiral M81 and zoom into the cores of quasars with VLBI and probe their dynamics. These studies will shed light on the astrophysics of the environment of a supermassive black hole and help establish a new fundamental celestial reference frame.