Theses and Dissertations

Date of Award


Document Type


Degree Name

Master of Science (MS)



First Advisor

Dr. Soumya D. Mohanty

Second Advisor

Dr. Soma Mukherjee

Third Advisor

Dr. Teviet Creighton


With next-generation radio telescopes, namely the Five-hundred-meter Aperture Spherical Telescope(FAST) and Square Kilometer Array(SKA), scheduled to come online during this decade, hundreds of well-timed millisecond pulsars (MSPs) will be added to the Pulsar Timing Arrays (PTAs) being used currently for Gravitational Wave (GW) searches. This will greatly increase the distances to which GW sources in the very low frequency band can be detected. Among these sources will be super massive black hole binaries (SMBHBs) formed out of gigantic black holes weighing in at million to billion times the mass of our Sun. Although the large number of MSPs will improve the sensitivity of PTAs, the associated data analysis challenges will also become harder. One challenge, which has been successfully addressed, is the exponential increase in the parameter space volume of GW signals due to a large number of so-called pulsar phase parameters. An even harder open challenge will be the need to resolve multiple sources, distributed in both signal frequency as well as signal loudness, in the data from future large-scale PTAs. We will present results from ongoing research using simulated large-scale PTA data that seeks to address the latter challenge. We follow a divide-and-conquer approach in which the search for sources is divided into different frequency bands and a single source search method is used recursively in each band to estimate and subtract sources. The per-band recursion is followed by a cross-band scheme inspired by an approach that was developed to mitigate interference from narrow band noise sources in the data of ground-based high-frequency GW detectors such as LIGO. At present, the combination of these two approaches allows us to resolve GW sources down to a level that is quite close to the noise floor of the data.


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