UTAPwiki/セミナー/宇宙物理学セミナー

Speaker: Minori Shikauchi

Title: On the use of CHIME to Detect Long-Duration Radio Transients from Neutron Star Mergers (電波望遠鏡CHIMEによるショートガンマ線バーストからの残光観測)

Abstract:
Based on the assumption that BNS merger may cause short gamma-ray bursts (Pazcynski1986, Goodman1986, Shemi&Piran1990, Paczysnki1990), a search for afterglows with radio telescope Canadian Hydrogen Intensity Mapping Experiment (CHIME) will provide an alternative measurement of the BNS merger rate relying on entirely different physical process and so will be an important confirmation of the GW-measured rate.

A previous research (Feng+2014) estimated the detectability of afterglows from SGRBs with respect to the circum medium density. They employed a fixed threshold in Janski to define "detectable". They concluded that up to 10^4 yr^{-1} afterglows can be detected with CHIME Pathfinder, a prototype of CHIME Full.

Here, we introduce a specific detection algorithm based on likelihood ratio statistics and simulate its response to signals embedded in noises. From the result, we also estimate a false alarm rate caused by the search over sky location and the choice of light curve templates. Taking all of that into consideration, we set a detection threshold based on target sample purity.

Assuming thermal noise is dominant, we estimated 50, 10 at least, and 154 at most afterglows per year can be detected with CHIME Pathfinder in one year observation. Our more detailed analysis leads to the prediction of a slightly smaller rate of detections, but it confirms the essential conclusion of the earlier analysis, namely that using CHIME to search for synchrotron afterglows will be effective.


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Last-modified: 2020-12-10 (木) 15:25:04 (36d)