Scholar news

Ridley and St. John to Study Eight Recently Discovered Pulsars

Physics faculty member, Dr. Joshua Ridley, and physics/math major and McNair Scholar, Demi St. John, will work to characterize eight newly discovered pulsars. Visible only from the Southern hemisphere, Ridley and St. John traveled to Australia in November of 2013 to use the Parkes Radio Telescope in New South Wales.

A pulsar, or rapidly rotating neutron star, is born when a very massive star ends its life in a supernova explosion. They can be discovered by observing the radio emission that they emit. As the pulsar spins, observers on the Earth detect a periodic signal, similar to what you might see when looking at a lighthouse. The discovery of these eight pulsars was originally published in a paper by Ridley et al. (2013) in the Monthly Notices of the Royal Astronomical Society. This project aims to measure the pulsars’ positions, ages, rates of rotation, magnetic field strengths and rates of energy loss.

To study the pulsars, the research team has been awarded 35 hours of telescope time spread over seven observational dates on the Parkes telescope. While the telescope may be operated remotely, Ridley and St. John needed to travel to Australia to receive training on how to use and operate the telescope. They will be able to complete all subsequent observations from Murray.

Collaborators on the project include Dr. Froney Crawford III from the Department of Physics and Astronomy at Franklin and Marshall College and Dr. Duncan Lorimer from the Department of Physics and Astronomy at West Virginia University. While in Australia, Ridley and St. John worked with John Sarkissian, a Parkes Observatory staff member, post-doctoral researchers Ryan Shannon and Matthew Kerr, and graduate student Dusty Madison, from Cornell University.

Ridley joined Murray State’s Department of Engineering and Physics in 2011. He obtained his M.S. and Ph.D. degrees in physics from West Virginia University and a B.S. in applied physics from Grove City College. His research includes pulsar searches, pulsar timing, and statistical simulations of pulsar populations in both our Galaxy and the Large and Small Magellanic Clouds.

St. John is a Murray State junior and a native of Edwardsville, Illinois. She joined the McNair Scholars Program, a Department of Education funded initiative at Murray State that prepares undergraduates from socioeconomically disadvantaged groups to enter Ph.D. programs in their chosen discipline, in August of 2012. In addition to supporting research trips like the one St. John went on to Australia, the McNair program provides Scholars with research stipends, scholarship support, and support for visiting graduate schools and participating in professional society conferences. St. John is the President of the Murray State Chapter of the Society of Physics Students and a member of Murray State's Honors Program.

Support for Ridley and St. John’s trip to Australia was provided by the Jones College of Science, Engineering and Technology, Murray State's McNair Scholars Program, the Department of Physics and Engineering, and through a housing award from the Australia Telescope National Facility.

Hannah Robbins Wins Poster Competition at the Annual Meeting of the Southern Branch of the American Society of Agronomy

Competing against students from schools like Purdue University, Texas A & M, Tarleton State University, Western Kentucky University and Mississippi Valley State University, Murray State University senior agronomy major and McNair Scholar, Hannah Robbins, won first place in the undergraduate research poster competition at the 2014 Annual Meeting of the Southern Branch of the American Society of Agronomy in Dallas, Texas.

Robbins’ project entitled, “Soil Carbon, Nitrogen and Aggregate Stability Associated with Common Agroecosystems in Western Kentucky,” was conducted under the guidance of Dr. Iin Handayani, Associate Professor of Agronomy in the Hutson School of Agriculture. Winning recognition for her research is not new to Robbins. She has previously won awards for her research posters and oral presentations at the Kentucky Academy of Sciences, Murray State University Sigma Xi Poster Competition, and the Southern Branch of the American Society of Agronomy conference in Orlando, Florida.

Results from Robbins’ project show that various agroecosystems in western Kentucky have different effects on the total carbon and nitrogen content and aggregation. The carbon results for wooded areas was only slightly higher than that found for pasture and crop fields. The highest total nitrogen was found in pasture and wooded areas (1.7 to 2.1 g kg-1). Crop fields had the lowest amount of total nitrogen (1.13 g kg-1). Wooded and pasture areas had the best aggregation as indicated by the highest macro-aggregate percentage and the ratio of macro-aggregates to micro-aggregates. The results support the hypothesis that the least disruptive management system will have the highest total nitrogen, total carbon and more desirable aggregation.

The annual meeting of the Southern Branch of the American Society of Agronomy, held in conjunction with the Southern Association of Agricultural Scientists, provides a venue for collaboration and networking among agronomy professionals and students in the Southern region and an opportunity for both graduate and undergraduate students to present their research findings.

Murray State's McNair program, which is intended to help prepare undergraduates for doctoral studies in their chosen fields, provided support for Robbins’ research project, travel support to the Southern Branch conference and other conferences and travel support to enable her to visit a number of graduate programs in her field. Robbins has been in the McNair program since August 2012 and will graduate from Murray State in May, 2014. She has applied to the agronomy graduate program at the University of Kentucky and is considering agronomy programs in North Carolina and Texas. Murray State's McNair program is funded through a grant from the U.S. Department of Education and through matching support from Murray State University.