- This event has passed.
Doctoral Defense
August 14, 2023 @ 1:30 pm - 2:30 pm
“Enabling the Future of Fast Transient Characterization: Building ArgusSpec and Prototyping the Argus Array”
Searches for short-duration astrophysical transients, such as stellar superflares, small planet microlensing events, and optical counterparts to gamma-ray bursts, are challenging due to their stochastic nature. To obtain significant numbers of detections, with sufficient time-resolution for characterization, fast-transient surveys must monitor large fractions of the sky at high cadence. The Evryscopes, a pair of northern and southern telescope arrays that image 38% of the night sky every two minutes, were designed to explore this challenging parameter space. As part of my research, I used the years-long light curve database from the Evryscope-South to perform a Southern Sky survey searching for young star variability. I report the finding of hundreds of new variable systems, including new discoveries of pre-main sequence eclipsing binaries. I further report the rapid spectroscopic follow-up of two large stellar superflares detected by the Evryscopes. Apart from dedicated staring campaigns of known active stars, these observations represent the lowest latency follow-up of superflares to date and allow us to characterize their blackbody continuum and temperature evolution. Developments in new mass-produced, wide-field, small-aperture telescopes allow the Evryscope concept to be scaled up to a new class of telescope: The Argus Array. Comprised of 900 telescopes, the Argus Array will image the entire visible sky with arcsecond resolution at high cadence. As part of my dissertation research, I developed components of the Argus Array prototypes: the Argus Array Technology Demonstrator and the Argus Pathfinder. In addition to this work, I describe my development of ArgusSpec, an autonomous, rapid-slew spectrograph which will provide spectroscopic follow-up of bright transient detections from the Evryscopes, Pathfinder, and the full Argus Array. ArgusSpec is built from low-cost, off-the-shelf components and can observe targets down to 20σ limiting magnitudes of mV = 13 (at 500 nm with an R = 150) using 30s exposures. The instrument serves as a prototype for a possible ArgusSpec Array, made of a dozen or more ArgusSpec units upgraded for improved sensitivity. Building such an array would allow individual telescopes to take observations of large numbers of bright transients simultaneously or perform multiplexed observations of one target to push magnitudes fainter.
Topic: Nathan Galliher’s Doctoral Defense
Time: Aug 14, 2023 01:30 PM Eastern Time (US and Canada)
Join Zoom Meeting
https://unc.zoom.us/j/92690385459?pwd=Yi9lSXIzTVB0TjVEemgxZDh6UEZZdz09
Meeting ID: 926 9038 5459
Passcode: 018811