We discuss design considerations and simulation results for IceRay, a proposed large-scale ultra-high energy (UHE) neutrino detector at the South Pole. The array is designed to detect the coherent Askaryan radio emission from UHE neutrino interactions in the ice, with the goal of detecting the cosmogenic neutrino flux with reasonable event rates. Operating in coincidence with the IceCube neutrino detector would allow complete calorimetry of a subset of the events. We also report on the status of a testbed IceRay station which incorporates both ANITA and IceCube technology and will provide year-round monitoring of the radio environment at the South Pole.
The IceCube Neutrino Observatory opened the window on neutrino astronomy by discovering high-energy astrophysical neutrinos in 2013 and identifying the first compelling astrophysical neutrino source, the blazar TXS0506+056, in 2017. In this talk, we will discuss the science reach and ongoing development of the IceCube-Gen2 facility---a planned extension to IceCube. IceCube-Gen2 will increase the rate of observed cosmic neutrinos by an order of magnitude, be able to detect five-times fainter neutrino sources, and extend the measurement of astrophysical neutrinos several orders of magnitude higher in energy. We will discuss the envisioned design of the instrument, which will include an enlarged in-ice optical array, a surface array for the study of cosmic-rays, and a shallow radio array to detect ultra-high energy (>100 PeV) neutrinos. we will also highlight ongoing efforts to develop and test new instrumentation for IceCube-Gen2.
In 2016, IceCube initiated a system of public real-time alerts that are typically issued within one minute, following the detection of a neutrino candidate event that is likely to be of astrophysical origin. The goal of these alerts is to enable multi-messenger observations that may identify the neutrino source. Through January 31, 2019, a total of 20 public alerts have been issued, with many of them receiving follow-up observations across multiple wavelength bands. One alert in particular, IceCube-170922A, was found to be associated with a flaring gamma-ray blazar, TXS 0506+056. This was the first >3 sigma association of a high-energy neutrino with an electromagnetic counterpart. In 2019, the IceCube collaboration is introducing a new set of neutrino candidate selections that expand the alert program. These new selections provide two alert channels. A Gold channel will issue alerts for neutrino candidates at least 50% likely to be of astrophysical origin and is expected to deliver $sim$10 alerts per year. Additionally a more frequent Bronze channel will provide $sim$20 alerts per year for neutrino candidates that are between 30% and 50% likely to be of astrophysical origin. We present the neutrino event selections used to generate these alerts, the expected alert rates, and a description of the alert message.
Multi-messenger astrophysics will enable the discovery of new astrophysical neutrino sources and provide information about the mechanisms that drive these objects. We present a curated online catalog of astrophysical neutrino candidates. Whenever single high energy neutrino events, that are publicly available, get published multiple times from various analyses, the catalog records all these changes and highlights the best information. All studies by IceCube that produce astrophysical candidates will be included in our catalog. All information produced by these searches such as time, type, direction, neutrino energy and signalness will be contained in the catalog. The multi-messenger astrophysical community will be able to select neutrinos with certain characteristics, e.g. within a declination range, visualize data for the selected neutrinos, and finally download data in their preferred form to conduct further studies.
IceCube has performed several all-sky searches for point-like neutrino sources using track-like events, including a recent time-integrated analysis using 10 years of IceCube data. This paper accompanies the public data release of these neutrino candidates detected by IceCube between April 6, 2008 and July 8, 2018. The selection includes through-going tracks, primarily due to muon neutrino candidates, that reach the detector from all directions, as well as neutrino track events that start within the instrumented volume. An updated selection and reconstruction for data taken after April 2012 slightly improves the sensitivity of the sample. While more than 80% of the sample overlaps between the old and n