Highest energy gamma rays detected from pulsar by UCD graduate


An international study led by three scientists including UCD Physics graduate, Andrew McCann of McGill University, and carried out with over one hundred scientists from various institutions across the globe, including UCD, has found the highest ever energy emissions from a pulsar.

In 1054 A.D. the remains of a star exploded, leaving behind the Crab Nebula. At the centre of this was the Crab Pulsar, which is a neutron star that spins at twenty-two revolutions per millisecond. The study focused on TEV gamma rays from the Crab Pulsar.


Head of the Very Energetic Radiation Imaging Telescope Array System (VERITAS) group in UCD, Dr John Quinn, explained that “a pulsar emits, like a lighthouse, a flash of radiation as the star spins”. It was these flashes of radiation that were the gamma rays studied by the team.

In the field of gamma ray astronomy, the Crab Pulsar and Nebula are very important, “it’s sort of like a reference point” explains Dr Quinn, “it was the best candidate for producing high-energy emissions, that’s why we targeted that one in particular; there are other pulsars which we could look at but this was the best candidate to detect high energy emissions”.

The study is particularly significant because the TEV gamma rays detected were the highest energy emission ever recorded from a pulsar. According to Dr Quinn, “this emission goes well beyond what is expected from theoretical models”.

As a result of these findings, “we have to go back and revisit our understanding of pulsars”. Aside from the theoretical implications that this will have in the field of astronomy, there are potential applications in industry and elsewhere. Namely, it could “have an implication in medical physics and other areas” says Dr Quinn.

Dr Quinn recalled the origin of the project, “going back about twenty years, it was a very small collaboration and UCD was one of the institutions that developed a new technique in astronomy; since then, we’ve joined with 20 other universities throughout the world and we have built an array of four telescopes that are located in Arizona, that search for gamma ray emission on various objects”.

Over fifty news agencies have picked up on the finding, something that Dr Quinn hopes could potentially see renewed interest in astronomy. He states that astronomy “is an excellent way to encourage kids to have an interest in science and results like this, that profile Irish scientists, are very good for Irish children to become interested in science.”

Dr Quinn continues to say that “after one hundred hours of observations with our telescopes focused on this object”, the research is not yet complete. Over the coming two years, the team “will probably take more data on it with our existing telescopes” before they can move on with their findings.