Abstract for Proposal 090335
X-ray sources and neutrinos: Investigating the most promising IceCube neutrinos
We propose to perform two 35 ksec ToO follow-up observations of X-ray
luminous sources that we identify in association with IceCube cosmic
high-energy neutrinos, using the AMON multimessenger framework. Since
identification of the first probable source of high-energy neutrinos in
2018, the blazar TXS 0506+056, multiwavelength follow-up of IceCube's
neutrino alerts has proven its utility for characterizing multimessenger
neutrino and electromagnetic sources, and we aim to use this approach
to identify more such sources. We will conduct XMM-Newton follow-up
studies of counterparts identified via Swift/XRT observations. While
capable of rapid response, Swift/XRT cannot constrain the X-ray spectra
of candidate counterparts with the precision needed for multimessenger
modeling studies.
Details on Observing Strategy and Trigger Criteria
With this program, we plan to trigger XMM-Newton observations only
if a. A high-confidence neutrino alert, called a ”Gold” alert
has been sent by IceCube with a > 60% chance of the neutrino being
astrophysical. b. Follow-up observations with Swift/XRT reveal a bright
X-ray source that is a potential counterpart OR if a well know X-ray
bright is within the neutrino uncertainty region. For most source
types, we do not expect variability on time scales below days, so a
follow-up within 1-2 weeks is sufficient for obtaining quasi-simultaneous
data. Multiwavelength programs at other wavelengths will provide insights
into variability, spectroscopy and the source identification.