The GW Astrophysics Group is currently focusing its attention on understanding the evolution of stars into compact objects, including white dwarfs, neutron stars, and black holes, as well as their end states. With new data from satellites capable of detecting X-rays and gamma rays from extraordinary sources a good fraction of the distance across the Universe, the field of high-energy astrophysics is particularly active, with the potential of solving current central puzzles, such as the nature of black holes, dark matter, dark energy, and the structure of the Universe.
A few years ago the Astrophysics Group, along with colleagues at the Goddard Space Flight Center of NASA, were the first to identify an object with the strongest magnetic field yet found in the Universe, this object recognized as a kind of neutron star called a magnetar. In the investigation of the behavior of matter in the plasma around astrophysical compact objects and to describe their cores, nuclear physics is an essential ingredient. Our senior group members grew up in the field of nuclear physics, and are now applying their knowledge to the rapidly growing research into gamma-ray bursts, active galactic nuclei, cataclysmic variables, and symbiotic stars. We are carrying on a research tradition in the GW Physics Department started by George Gamow. Gamow was the first to describe radioactivity as quantum tunneling, began the theory of nucleosynthesis, and developed the hot big bang theory of the Universe.
One of the goals on the frontier of physics research is to understand exotic processes occurring near dense astrophysical objects: The study of these objects will reveal nature under extreme conditions, test our models at their boundaries, provide the information needed to predict what will happen to such bodies, and perhaps point toward an of extension our theories to new realms, and to new ways to control energy.
When a star gravitationally collapses producing a supernova, or when two compact stars explode after fusing, or when a white dwarf in a close binary system produces a nova, we expect a sudden pulse of gravitational waves, neutrinos, and light. After the initial burst of energy, the residue of the ejected material continues to radiate through various known mechanisms. Most of our information about these outbursts comes from investigation of the light emitted because neutrinos are barely detectable, and gravity wave detectors are at present insufficiently sensitive. We analyze the information contained in the light over the full electromagnetic spectrum to determine the nature of the pulses, their energy, their variability, and their temporal correlations. The results of this analysis can then be used to see if our present models of plasma physics and the equations of exotic states of matter work.
Leonard C. Maximon
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Our research has been funded by grants from NASA.