USRA scientists, in collaboration with scientists around the world, are contributing to our understanding of a wide array of current astrophysical problems, using nearly the full-range of the electromagnetic spectrum. Current work enabled by USRA includes the turbulent youth and explosive death of stars, the largest gravitationally-bound structures in the universe, the behavior of matter under the most extreme conditions and the origin of gravitational waves and high-energy cosmic rays, and the creation of the universe itself.
Stunning Discovery of Colliding Neutron Stars
USRA was a key collaborator in the new gravitational wave discovery—the first detection by multiple space and ground-based observatories.
This phenomenal event resulted from colliding neutron stars and was detected by NASA’s Fermi Gamma-ray Burst Monitor (GBM) on August 17, 2017. Fermi’s GBM instrument is operated by USRA for NASA.
The gravitational waves were picked up by the Laser Interferometer Gravitational Wave Observatory detectors at Hanford, Washington. This joint detection set in motion a series of observations across the electromagnetic spectrum from radio waves to very-high-energy gamma rays, resulting in multiple views of a fascinating phenomenon in our cosmological backyard, about 130 million light years from Earth.
USRA scientists working on this observation soon realized the extraordinary nature of this event.
As the observations of the gravitational waves unfolded, the impact of the discovery became evident. It confirmed a binary neutron stars merger as the origin of at least some short Gamma Ray Bursts (GRB). But just as importantly, the proximity in time of the Gravitational Wave and the Gamma Ray Burst detections showed that gravity waves travel at velocities that deviate from light speed by less than one part in one quadrillion.
Of the several published papers that have resulted from this major discovery, three appeared in Astrophysics Journal Letters, coauthored by USRA scientists Adam Goldstein and B.P. Abbott.
SOFIA Observes Solar System Analog
Using the mid-infrared camera FORCAST on SOFIA, University of Arizona’s Kate Su and colleagues resolved the long-standing question of the nature of the dust surrounding the nearby star epsilon Eridani. The dust in the inner 25 AU of the epsilon Eridani debris disk system arises principally from collisions between planetesimals in a dust disk similar to Sun’s asteroid belt, rather than by grains dragged in from a cold outer belt, like the Sun’s Kuiper belt.
Fast Radio Bursts— Originating Long, Long Ago in a Galaxy Far, Far Away
For the first time, scientists have clearly established the host galaxy of a Fast Radio Burst (FRB) — one of astronomy’s hottest topics. FRBs, which are very short, very intense pulses of radio waves, have puzzled astronomers since their discovery a decade ago. Twenty-three of these bursts have been recorded by telescopes around the world, but only one—discovered at Arecibo Observatory in Puerto Rico—has ever repeated.
USRA scientists at Arecibo joined the European Very-Long-Baseline Interferometry Network to pinpoint the location of the FRB in a dwarf galaxy over 3 billion light-years away. These observations provide definitive proof that FRBs come from far outside our Milky Way.
Dwarf galaxies contain gas that is relatively pristine compared to that found in the more massive Milky Way. Conditions in this dwarf galaxy may make it possible to form much more massive stars than in the Milky Way, and the FRBs could be from the collapsed remnant of such a star. Alternately, FRBs could also be generated in the vicinity of a massive black hole that is swallowing the surrounding gas, a so-called active galactic nucleus. There is still a lot of work to be done to unravel the FRB mystery, but identifying the host galaxy for Arecibo’s FRB marks a big step toward solving the puzzle.
Dr. William Reach
Stratospheric Observatory for Infrared Astronomy (SOFIA)
SOFIA is an airborne observatory which conducts observations that are impossible for even the largest and highest ground-based telescopes. SOFIA flies at 38,000 - 45,000 feet to observe in infrared light, which does not reach the Earth's surface. SOFIA is an 80/20 partnership of NASA and the German Aerospace Center (DLR), consisting of an extensively modified Boeing 747SP aircraft carrying a reflecting telescope with a 2.7-meter (106 inch) diameter. The aircraft is based at NASA's Armstrong Flight Research Center in Palmdale, California. NASA’s Ames Research Center in California's Silicon Valley manages SOFIA's science and mission operations, in cooperation with the USRA and the German SOFIA Institute at the University of Stuttgart.
Dr. William Reach, Director
Science and Technology Institute (STI)
In collaboration with NASA and The University of Alabama in Huntsville, USRA’s STI fosters research efforts that include astrophysics, space science, new technology studies, and educational activities. Space science research includes gamma-ray astronomy, X-Ray astronomy, cosmic ray physics, solar physics and space physics.