Day 1444

Wednesday.

1807.08794
Neutrino emission from the direction of the blazar TXS 0506+056 prior to the IceCube-170922A alert
IceCube Collaboration

A high-energy neutrino event detected by IceCube on 22 Sept. 2017 was coincident in direction and time with a gamma-ray flare from the blazar TXS 0506+056.  Prompted by the association, investigate 9.5 years of IceCube neutrino observations to search for excess emission at the position of the blazar.  Found an excess of high-energy neutrino events with respect to atmospheric backgrounds at that position between September 2014 and March 2015.  Allowing for time-variable flux, this constitutes 3.5 sigma evidence for neutrino emission from the direction of TXS 0506+056, independent of and prior to the 2017 caring episode.  This suggests that blazers are the first identifiable sources of the high-energy astrophysical neutrino flux.


1807.08816
Multi-messenger observations of a flaring blazar coincident with high-energy neutrino IceCube-170922A
IceCube, Fermi-Lat, MAGIC, AGILE, ASAS-SN, HAWC, HESS, INTEGRAL, anata, Kiso, Kapteyn, Liverpool telescope, Subaru, Swift/NuSTAR, VERITAS, VLA/17B-403 teams

An extensive multi-wavelength campaign followed the event, ranging from radio frequencies to gamma-rays.  These observations characterize the variability and energetics of the blazar and include the first detection of TXS 0506+056 in very-high-energy gamma-rays.  This observation of a neutrino in spatial coincidence with a gamma-ray emitting blazar during an active phase suggests that blazers may be a source of high-energy neutrinos.


1807.09004
A dark matter hurricane: measuring the S1 stream with dark matter detectors
O'Hare, McCabe, et al

The recently discovered S1 stream passes through the Solar neighborhood on a low inclination, counter-rotating the orbit.  The progenitor of S1 is a dwarf galaxy with a total mass comparable to the present-day Fornax dwarf spheroidal, so the stream is expected to have a significant DM component.  Compute the effects of the S1 stream on WIMP and axion detectors as a function of the density of its unmeasured dark component.  In WIMP detectors the S1 stream supplies more high energy nuclear recoils so will marginally improve DM detection prospects.  Find that even if S1 comprises less than 10% of the local density, multi-ton xenon WIMP detectors can distinguish the S1 stream from the bulk halo in the relatively narrow mass range between 5 and a 25 GeV.  In directional WIMP detectors such as CYGNUS, S1 increases DM detection prospects more substantially since it enhances the anisotropy of the WIMP signal.  Finally, show that axion haloscopes possess by far the greatest potential sensitivity to the S1 stream.  Once the axion mass has been discovered, the distinctive velocity distribution of S1 can easily be extracted from the axion power spectrum.