High Precision and Long Duration Timing of Exotic Pulsars in Globular Clusters

Associated Universities, Inc., Vienna VA

Investigators

Abstract

Radio pulsars are spinning neutron stars that act as cosmic clocks, allowing us to make precision measurements of a wide variety of astrophysical processes. Some of the most interesting radio pulsars are those that spin hundreds of times per second, the so-called millisecond pulsars (MSPs). Most MSPs are in binary systems with another star, and the clock-like pulsations can be used to measure those orbits extremely precisely. The Principal Investigator has used the NSF-funded Green Bank Telescope (GBT) over the past 20 years to monitor known MSPs and to discover new MSPs. Using new and improved algorithms, he will use these data to produce long-term binary timing solutions and derive critical properties of more than 70 MSPs, as well as to potentially discover 6-12 new pulsars. The data will also be made publicly available so other research groups can conduct their own experiments. The project will provide training and support for the next generation of scientists, including two graduate students at the University of Virginia and numerous high school and undergraduate students through the citizen science project Pulsar Science Collaboratory. The amount of science that pulsars produce tends to increase with the overall timespan over which they are monitored, with decades-long observing campaigns being extremely rare and valuable. Such studies can inform our understanding of stellar evolution, binary dynamics, the physics of matter at supranuclear density, and the low-frequency gravitational wave universe. The work carried out by the PI and graduate students includes obtaining and analyzing the data from new GBT observations to search for new pulsars and increase long-term timing baseline for known pulsars, continuing analysis of the PI’s existing GBT data in combination with the new observations from GBT and other telescopes. Much of the PI’s existing data resides on external hard drives, and they will be uploaded to the GBT archive, where it will be publicly available. The scientific impact of the program is enhanced by the potential to provide 20 years of timing data for any pulsar discovered with the new observations or by other groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.