Speaker
Description
In recent years, magnetic turbulence in the hot coronae of Seyfert galaxies has been proposed as a potential source for high-energy neutrino production. This model predicts that the signal strength of neutrinos originating from the coronae correlates with X-ray intensity, and experimentally constraining this correlation could provide a deeper understanding of high-energy neutrino and cosmic ray production models. In this study, we developed and tested a method to evaluate the time correlation between X-ray and neutrino observational data from a Seyfert galaxy, using approximately 10 years of continuous observations from MAXI and IceCube. First, we assumed a correlation function with several parameters between X-rays and neutrinos. Then, focusing on nearby, X-ray-bright Seyfert galaxy, we used MAXI's observational results and this correlation function to generate neutrino data corresponding to the X-rays. We optimized the parameters through simulations based on pseudo-observational data. By defining correlation detection confidence as the percentile position of the median of the parameter histogram fitted under a correlation assumption, relative to the histogram of parameters under the assumption of no correlation, we were able to impose constraints on the number of neutrino detections by IceCube necessary to identify the correlation. Specifically, we found that if 34 or more neutrinos are detected from NGC 4151 over 3,804 days, the correlation between X-rays and neutrinos from the galaxy could be analyzed with over 90% confidence using this method, representing a stricter constraint than previous limits.
