Featured Astrophysics Research Projects
ASD's Stanley Hunter is leading a team to develop an instrument called a Three-Dimensional Track Imager (3-DTI). The instrument will provide optimum angular resolution for observing medium-energy gamma rays
(~5 to 500 MeV). Hunter's team has also tested the 3DTI technology, with funding from the Office of Naval Research, for use in detecting special nuclear materials from moderate stand-off distances. The materials are isotopes of uranium and plutonium that could be used by hostile entities to fashion a "dirty bomb" or an actual nuclear explosive device.
For more information, contact Stanley Hunter.
The Calorimetric Electron Telescope (CALET) is an instrument package scheduled to launch in 2014 to the International Space Station on a Japanese rocket. The instruments include a high-energy particle telescope and a gamma-ray burst monitor. The ASD team of John Mitchell, Thomas Hams, John Krizmanic, Alexander Moiseev, and Makoto Sasaki are responsible for the instrument simulation and performance model; technical support for instrument development; and leadership of U.S. support for accelerator testing and calibration.
For more information, see the Louisiana State University CALET website.
ExoPlanets and Stellar Astrophysics
Theodore (Ted) Gull studies the nearby star Eta Carinae, an evolved-binary system some 7,500 light years from Earth. Eta Carinae is notable for being a likely precursor to a hypernova, an event in which the collapse of a massive star, for a few seconds, can emit the equivalent to the radiant energy output of an entire universe of galaxies. The system, with erratic variations, has continued to brighten over the past century. Gull, in collaboration with many observers and modelers, continues to characterize Eta Carinae's behavior using data from the Hubble Space Telescope, the Chandra X-ray Observatory, the Herschel Space Observatory, and other facilities.
Richard Lyon and Mark Clampin and colleagues are developing an instrument technology, called the visible nulling coronagraph (VNC), for directly detecting and characterizing extrasolar planets. The VNC suppresses the light from a planet's host star, making the light from the planet available for imaging and spectroscopy. The nulling coronagraph will split incoming light from the telescope into two beams. One beam travels a slightly longer path, so the light waves from the star get out of step with the waves of starlight in second beam. When the beams are recombined, the light waves from the star cancel.
Contact Richard Lyon for more information.
Ground-based gravitational wave detectors (e.g., LIGO and Virgo) are subject to transient noise events that mimic astrophysical signals. Tyson Littenberg and Neil Cornish at Montana State University have been working to build data analysis software that can be used to automatically find and remove these noise "glitches." Doing so increases the effective sensitivity of the detectors by reducing the probability that a candidate detection could actually be caused by instrumental effects.
For more information, see http://lanl.arXiv.org/abs/1008.1577.
Astrophysicist Jane Rigby studies the inner workings of star-forming galaxies at the epoch of peak galaxy growth, using multiwavelength imaging and spectroscopy. Much of her work targets gravitationally lensed galaxies, taking advantage of magnification factors of 10-30x. In her research, Rigby uses a wide range of telescopes on the ground and in space. These include the Hubble, Spitzer, Herschel, and Chandra space observatories, and the Keck and Magellan telescopes in Hawaii and Chile.
For more information, contact Jane Rigby.
Goddard researchers William Zhang, Andrew Ptak, Ann Hornschemeier, Jane Rigby, Stacy Teng, and Dan Wik are members of the Science Team developing science plans for the Nuclear Spectroscopic Telescope Array (NuSTAR). Planned investigations will focus on star-forming galaxies, ultraluminous infrared galaxies, obscured active galactic nuclei, and galaxy clusters. The Nuclear Spectroscopic Telescope Array will allow astronomers to study the universe in high energy X-rays. NuSTAR is slated for launch in 2012.
ASD's Keith Gendreau and Zaven Arzoumanian are working with NASA Goddard engineers to develop a technology, called XNAV, that would allow spacecraft to navigate autonomously using X-ray timing signals from rotating neutron stars (pulsars). Proposals are in progress to deploy the technology in one of three ways: 1) As a demonstration mission aboard the International Space Station (ISS); 2) As a supplement to a science mission, the Neutron Star Interior Composition Explorer (NICER); or 3) As a combined technology demonstration/science instrument package called the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT). All three options involve substantially the same hardware payload on the ISS.
The X-ray Quantum Calorimeter (XQC) is an X-ray spectrometer to study the soft X-ray background in the band from 0.05 to 2 keV with very high energy resolution. The instrument will be operated on a sounding rocket, and has a 1 steradian field of view with a spectral resolution of ~8 eV at 1 keV. ASD research team members include F. Scott Porter, Richard Kelley, Caroline Kilbourne, and Megan Eckart. Collaborating institutions include the University of Wisconsin-Madison (PI), the University of Miami, and Yale University. The spectrometer was built to differentiate the spectral components that make up the ubiquitous soft X-ray background. The XQC has flown five times since 1995, with the most recent flight in November 2011. Additional flights are planned to further investigate the spatial and spectral distribution of the soft x-ray background.
For more information, contact F. Scott Porter.