This is an award for a research program in cosmic ray astrophysics focused on the Pierre Auger Observatory (PAO), an instrument designed to investigate the origin and nature of the Ultra High Energy Cosmic Rays having energies above 10^19 eV. Data from the PAO will help to answer a number of the most fundamental questions about cosmic ray origins, composition, acceleration mechanisms, and propagation effects and may shed light on hadronic physics at center-of-mass energies up to 450 TeV.
This group has led the development of the offline analysis software framework and made contributions to physics analysis. They plan to continue their role in software development and to extend their analysis efforts using new data.
The broader impact of the program includes the development of technologies and methodologies which cross domains such as connections with computer science and laboratory-based particle physics, and a vigorous outreach program involving regular newspaper, radio, and television appearances in several countries.
Particle astrophysics connects particle physics - the study of the fundamental nature of matter and the forces by which it interacts, and astrophysics - the study of the nature and behavior of objects in the cosmos. As such it concerns scales both very large and very small and can truly be said to embrace the universe on all scales. Our research focuses on cosmic rays. Cosmic rays are subatomic particles from outer space; you have a few pass through you every second, quite harmlessly. These particles comprise part of the natural background radioactivity. Most cosmic rays carry relatively little energy, but with lower and lower probability, particles carrying more and more energy are found to reach us - some with energies as much as a well-hit tennis ball, but with all that energy carried by a single proton or atomic nucleus. This in itself is remarkable. When these particles strike molecules in the upper atmosphere, they initiate huge showers of lower energy particles - many billions - which travel through the atmosphere inducing a faint glow of ultraviolet light and ultimately striking the earth over an area of several square miles. The Pierre Auger Observatory employs electronic "eyes" to observe that tiny glow as well as 1,600 instrumented tanks of water spaced 1.5 km apart in the Argentine pampas which measure the particles in the shower that reach the ground. The highest energy ones are so rare that we need a huge detector to get a reasonable sample study. We've been contributing to the operation and maintenance of the observatory, mainly via coordinating and maintaining all the software using data from the observatory and by working on the analysis of the data. We're trying to understand exactly what the cosmic particles are, how they acquire such enormous energies, and how they propagate across millions of light years through the cosmos to reach us. At the highest energies, this opens up a new type of astronomy whereby we can try to see things not by the light they emit, but by high energy particles they eject. Lower energy particles can also help us study magnetic fields in space by looking at how they get deflected en route to us. We can also use these particles to study fundamental physics at energies much higher (corresponding to distances much smaller) than can be reached even at the LHC at CERN - the most powerful machine we've been able to build on earth. Celestial objects achieve vastly higher energies than we have been able to! Of course we can't control the big accelerators in space, but we can use them and are actually able to do some things that are still well out of reach of the LHC. For example, our group has been able argue that if there are hidden dimensions of space, they must be smaller than even the LHC can see - and we can draw these conclusions with an accelerators we don't even control, and which lie millions of light-years away! In addition to adding to our collective knowledge both of how physics works at astrophysical and subatomic scales, students and postdocs get trained in research, engineering and technology, as do already well-established scientists - we're always learning. In addition to writing scholarly works (which can be hard for the layperson to read), we also try very hard to communicate our results to the general public via websites, talks, popular articles, radio, TV, etc. It's very important to us that people can share the excitement of what we're doing and learning. Sometimes people ask what immediate application this sort of work might have and the honest answer is: we don't know yet. For many of us, the adventure of the human mind trying to understand how the universe works and what our place in it is, is its own reward. That said, basic research often leads to major and unexpected technologies. Not too many years ago electricity was a mere laboratory curiosity, and much more recently (just 20 years ago) the world wide web came out CERN as a tool to help physicists communicate and share data. Finally, we're a good example of how diverse people from differing countries and cultures can come together to build major projects and work together and surely that's a good thing in times when the news might suggest that people aren't good at getting along.
