Several long, thin, “filament” structures have been detected shooting out from nearby pulsars. They’re made of electrons and positrons recently manufactured by the pulsar and shooting into the ambient medium at as much as 99.9999999999% (twelve 9’s) the speed of light.
Our twin effort is to find more filaments to characterize them, and build a physical model for the particles’ propagation through space. Do they reach Earth? Are the positrons we detect in the upper atmosphere brought to us by these filaments? See the interactive figure for a display of my results. [arXiv:---]
Save Chandra
NASA’s funding for Chandra, the world’s sharpest X-ray telescope, was sharply reduced in the most recent NASA budget. This action will severely damage or possibly destroy the twenty-five year pipeline of X-ray photons to science which has sustained thousands of scientists and made many incredible pictures such as those on the left.
Many scientists are calling for Chandra’s budget to be restored for as long as it is technologically capable of producing great science. See what you can do to help by visiting savechandra.org.
Polarization Leakage
IXPE, the first ever telescope to detect X-ray polarization, opens a new frontier for understanding pulsars and other high energy objects. But X-ray polarization measurements are made difficult by detector systematics that add distorting patterns onto the imaged polarizations (left).
I developed a method to predict and subtract this polarization to reveal the true polarization of the source. [arXiv: 2401.10231]
Probing Asteroids with Gravity
In 2029, an asteroid named Apophis will fly closer to Earth than any yet-measured asteroid. Earth’s tidal tug will change its spin axis in a way that will reveal the composition deep within the asteroid where light cannot reach.
My work determined the observational precision needed to extract the asteroid’s properties from the changes in its spin axis, and demonstrated a few methods to translate those observations into an asteroid map. [arXiv: 2210.10754]
Dark Matter Physics in the Galactic Center
The Fermi Gamma-ray Space Telescope detected an excess of high energy emission coming from the center of our Galaxy, which might have been a signature of dark matter colliding with itself, exploding into light.
But our work joins a growing set of literature which suggests that the emission could instead come from many dim, undiscovered pulsars. We show that the pulsar physics we know is consistent with this pulsar explanation, and that improved data or data analysis techniques could reveal some—even many—of these hidden pulsars. [arXiv: 2112.09699]
