Physical Sciences and Mathematics Commons^™

Deep Radio Observations And The Role Of The Cosmic Web In Galaxy Evolution, Nicholas M. Luber

Graduate Theses, Dissertations, and Problem Reports

A current open question in the evolution of galaxies, is what are the physical mechanisms that cut off galaxies from their primordial gas reservoirs, resulting in the end of their star-formation capabilities? Recent observational programs have shown that the properties of galaxies show dependencies on their placement within the large-scale structure (LSS) of the universe. These observations have motivated recent developments in theoretical work that have shown how a galaxy's interaction with the LSS may impact its connection to primordial gas supply, and ability to continue to accrete gas, the fundamental ingredient in star-formation.

In order to investigate the role …

Identification And Classification Of Radio Pulsar Signals Using Machine Learning, Di Pang

Graduate Theses, Dissertations, and Problem Reports

Automated single-pulse search approaches are necessary as ever-increasing amount of observed data makes the manual inspection impractical. Detecting radio pulsars using single-pulse searches, however, is a challenging problem for machine learning because pul- sar signals often vary significantly in brightness, width, and shape and are only detected in a small fraction of observed data.

The research work presented in this dissertation is focused on development of ma- chine learning algorithms and approaches for single-pulse searches in the time domain. Specifically, (1) We developed a two-stage single-pulse search approach, named Single- Pulse Event Group IDentification (SPEGID), which automatically identifies and clas- …

Phased Array Feed Beamforming And Its Application In Mapping Extended Sources, Gargi Roy

Graduate Theses, Dissertations, and Problem Reports

Ever since the detection of radio signals, technology has strived to improve the performance of the hardware associated with detecting and observing faint radio sources by improving signal processing and detection techniques. Phased array feeds (PAFs) for radio telescopes can yield in an increase in the survey speed and field of view for reflector antennas. Beamforming, calibration, and imaging are some of the challenges that need to be addressed in order to further the development of PAFs. There is a trade-off between achieving high sensitivity and maintaining a stable clean beam pattern when it comes to beamforming design strategies. A …