[Paper Review] Multi-messenger studies with amanda/icecube: observations and strategies

A. Achterberg, A. C. Pohl+200 more|arXiv (Cornell University)|Sep 14, 2005

Astrophysics and Cosmic Phenomena3 citations

TL;DR

This paper presents a four-year search for high-energy neutrinos from point sources using AMANDA-II, finding no significant excess but identifying a notable temporal coincidence between neutrino events and gamma-ray flares from the blazar 1ES1959+650. The results motivate enhanced multi-messenger strategies between AMANDA/IceCube and gamma-ray observatories for future joint source investigations.

ABSTRACT

Four years of AMANDA-II data have been searched for neutrinos from point sources. No statistically significant excess of events has been detected, neither integrated in the years 2000 to 2003, nor in the searches for occasional signals. An interesting coincidence of neutrinos with gamma-ray flares emerges when inspecting the time of the events detected from the direction of the Blazar 1ES1959+650. The exceptional character of the gamma-ray observation provides a strong motivation for consolidating similar search strategies with AMANDA and its successor IceCube, as well as for multidisciplinary investigations of this and other gamma-ray sources. We report the outcomes of the most recent survey of the northern sky to search for neutrino point sources with AMANDA-II. We also discuss possible viable collaborations between the gamma-ray and the high energy neutrino observatories.

Motivation & Objective

• To search for high-energy neutrino point sources in four years of AMANDA-II data (2000–2003).
• To investigate potential temporal correlations between neutrino events and gamma-ray flares from known sources, particularly 1ES1959+650.
• To evaluate the feasibility and value of coordinated multi-messenger studies between high-energy neutrino and gamma-ray observatories.
• To develop strategies for future joint analyses using IceCube and gamma-ray instruments.

Proposed method

• Analysis of AMANDA-II data from 2000 to 2003 for neutrino events coinciding with known point sources.
• Application of directional and temporal coincidence searches to identify potential neutrino emission from transient sources.
• Focus on the blazar 1ES1959+650 due to its exceptional gamma-ray activity during the observation period.
• Use of statistical methods to assess significance of event clusters in time and direction.
• Comparison of neutrino event timing with gamma-ray flare light curves to detect correlations.
• Proposal of collaborative frameworks between neutrino and gamma-ray observatories for coordinated source monitoring.

Experimental results

Research questions

• RQ1 Is there a statistically significant excess of high-energy neutrinos from point sources in AMANDA-II data from 2000 to 2003?
• RQ2 Do neutrino events detected from the direction of 1ES1959+650 show temporal correlation with its gamma-ray flares?
• RQ3 What is the significance of the observed coincidence between neutrino events and gamma-ray activity in 1ES1959+650?
• RQ4 How can high-energy neutrino and gamma-ray observatories improve joint detection strategies for transient sources?
• RQ5 What are the viable pathways for sustained multi-messenger collaboration between AMANDA/IceCube and gamma-ray facilities?

Key findings

• No statistically significant excess of neutrino events was detected from any point source in the four-year AMANDA-II dataset.
• A notable temporal coincidence was observed between neutrino events and gamma-ray flares from the blazar 1ES1959+650.
• The exceptional nature of the gamma-ray flare from 1ES1959+650 strengthens the case for targeted neutrino follow-up observations.
• The observed coincidence, while not statistically significant on its own, provides a compelling motivation for future coordinated multi-messenger studies.
• The results support the development of joint search strategies between high-energy neutrino and gamma-ray observatories.
• The study highlights the potential of multi-messenger astronomy in probing extreme astrophysical sources like blazars.