Welcome to NMCPP!
The New Mexico Center for Particle Physics (NMCPP) exists to promote cooperative program(s) in the general research areas of particle physics and particle astrophysics within UNM and with neighboring institutions in NM. Additionally, the NMCPP web pages provide an opportunity to bring these research programs to the attention of prospective undergraduate and graduate students.The NMCPP conducts research in the following areas:- High Energy/Elementary Particle Physics
- Medium Energy Physics
- Nuclear/Particle Theory
- Particle Astrophysics
Looking for an exciting research opportunity? Check out our current opportunities and consider joining the researchers and students at NMCPP.
Supermassive black holes may answer long-standing mystery - by Steve Carr
Scientists of the Pierre Auger Collaboration, which includes researchers in UNM's Department of Physics and Astronomy, recently announced that Active Galactic Nuclei or AGNs are the most likely candidate for the source of the highest-energy cosmic rays that hit Earth. The results appeared in the Nov. 9 issue of Science.
Using the Pierre Auger Observatory in Argentina, the largest cosmic-ray observatory in the world, a team of scientists from 17 countries found that the sources of the highest-energy particles are not distributed uniformly across the sky.
Instead, the Auger results link the origins of these mysterious particles to the locations of nearby galaxies that have active nuclei in their centers.
Supermassive black holes devouring large amounts of matter are thought to power AGNs. They have long been considered sites where highenergy particle production might take place. They swallow gas, dust and other matter from their host galaxies and spew out particles and energy.
While most galaxies have black holes at their center, only a fraction of all galaxies have an AGN. The exact mechanism by which AGNs accelerate particles to energies 100 million times higher than the most powerful particle accelerator on Earth is still a mystery.
Galaxies that have an AGN seem to be those that had a collision with another galaxy or other massive disruption in the last few hundred million years. The AGN swallows mass coming its way while releasing prodigious amounts of radiation. The Auger results indicate that AGNs may also produce the universe's highest-energy particles.
"We looked at our cosmic rays and tried to see if they correlated with a category of astrophysical sources [the AGNs] because there aren't enough of them to come from any one source," said UNM Professor John Matthews. "Normally you would say it should be some bright object in the sky. The trouble is they aren't. We're stuck trying to correlate what we actually measure with possible sources. The AGNs are supermassive black holes and that's what's cool about them."
"There are very few events to measure to help make the correlation," said graduate student J. Doug Hague, another researcher from UNM. "Imagine your telescope only gives you one photon a month. How would you determine where the stars are? Here it takes a year or more with one single light pulse [one cosmic ray] at a time."
Cosmic rays are protons and atomic nuclei that travel across the universe at close to the speed of light. When these particles smash into the upper atmosphere of our planet, they create a cascade of secondary particles called an air shower that can spread across 40 or more square kilometers (15 square miles) as they reach the Earth's surface.
"It turns out that supermassive black holes tend to be everywhere and they are incredibly efficient at converting gravitational energy into other forms of particle beams," Matthews said.
Other UNM scientists participating in the research include Professor Michael Gold, Instrumentation Specialist Bill Miller and Post Doctorate Bernie Becker.