Research at the WVU Center for Astrophysics
Pulsar Astrophysics We carry out a variety of searches for new pulsars using large radio telescopes around the globe with the goal of understanding the neutron star population in our Galaxy, the study of exotic binary systems, and finding highly precise millisecond pulsars for gravitational wave detection.
Transient radio sources Pulsar surveys are currently the only probes of the transient radio sky on extremely short (< few second) timescales. During our searches for periodic signals, we also scour the data for impulsive burst-like events. This has so far resulted in the discovery of a new class of neutron stars and a powerful burst of radio waves from an extragalactic source.
Gravitational physics Through pulsar timing we can probe many areas of fundamental physics. Our studies of the double pulsar system have so far provided the most stringent constraints on Einstein’s theory of general relativity in the strong-field regime and demonstrate the existence of graviational waves – ripples in space time caused by the acceleration of massive objects. One of the holy grails of physics is the direct detection of gravitational radiation. We are part of an international collaboration to use millisecond pulsars as detectors for the background of low-frequency gravitational waves expected from various cosmological sources.
Searching for the gaseous remnants of galaxy formation Galaxies form by the accretion of small clouds of gas, stars and dark matter, slowly building up a larger galaxy. While this process began early in the history of the Universe, there are potentially still clouds of gas around galaxies today. The high velocity clouds (HVCs) around the Milky Way are clouds of gas around the Milky Way with unknown distances and, hence, unknown origins that may be linked to galaxy formation. Alternatively, they may instead originate from star forming regions in the Milky Way or via interactions with neighboring galaxies, or from a combination of processes. We have been using radio telescopes around the world to study the HVCs around the Milky Way and around other galaxies in order to constrain their potential origins.
The evolution of star-forming galaxies Over the past eight billion years, the star formation rate of the universe has plummeted by a factor of ten, while the galaxy population has evolved from primarily blue, star-forming galaxies into quiescent red galaxies. Astronomers do not yet understand why these transformations have occurred. A possible key to understanding these changes are the luminous, compact, blue galaxies (LCBGs) that represent the high mass end of blue, star-forming galaxies. They were common eight billion years ago, but are extremely rare today. We are part of an international collaboration that has been conducting a multi-wavelength study of LCBGs in the nearby and distant universe in order to constrain their current nature and their evolutionary fate. Our study will help to explain why the galaxy population changed from blue to red and why star formation has rapidly declined over the past eight billion years.
Radio astronomy technology The future of radio astronomy relies on new instrumentation to enable further advances in sensitivity. We are currently investigating possible designs for the Square Kilometer Array, and helping to design the next generation of digital spectrometers. We are also closely involved in the development of a focal plane array for the Green Bank Telescope.