Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Physics (MS)

Administrative Home Department

Department of Physics

Advisor 1

Petra Huentemeyer

Committee Member 1

Robert Nemiroff

Committee Member 2

David Nitz


The Cygnus Cocoon is an extended source of high-energy gamma-ray emission in the Cygnus region. The gamma-ray emission has been attributed to a volume 50pc in diameter of freshly-accelerated particles near the Supernova Remnant γ Cygni which is located 1.4kpc from the solar system [Ackermann et al., 2011], [Tibaldo et al., 2013]. Since its discovery in 2011, Fermi LAT has improved their event reconstruction to allow analysis at higher energies, and recorded six additional years of data. An analysis was performed on the entire dataset to reproduce the previous results, then expand on them with higher energies and larger time spans of data. No evidence of temporal variability was found for the Cocoon. It was found that for the energy range of 1-870 GeV a logparabola spectrum is preferred over a powerlaw spectrum. Analysis is then done comparing the Cocoon spectrum measured using LAT data with a HAWC source [Hona et al., 2017] that is thought to be the Cocoon. It was found that the LAT powerlaw spectrum connects with the HAWC spectrum at 1 TeV, while the LAT powerlaw spectrum is an order of magnitude lower then the HAWC source. This means that for the combined analysis the powerlaw spectrum is prefered over the logparabola, if the HAWC source is the Cocoon.