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Full-Text Articles in Physics
Multiwavelength Follow-Up Of A Rare Icecube Neutrino Multiplet, Karen Andeen
Multiwavelength Follow-Up Of A Rare Icecube Neutrino Multiplet, Karen Andeen
Physics Faculty Research and Publications
On February 17, 2016, the IceCube real-time neutrino search identified, for the first time, three muon neutrino candidates arriving within 100 s of one another, consistent with coming from the same point in the sky. Such a triplet is expected once every 13.7 years as a random coincidence of background events. However, considering the lifetime of the follow-up program the probability of detecting at least one triplet from atmospheric background is 32%. Follow-up observatories were notified in order to search for an electromagnetic counterpart. Observations were obtained by Swift’s X-ray telescope, by ASAS-SN, LCO and MASTER at optical wavelengths, …
Search For Astrophysical Sources Of Neutrinos Using Cascade Events In Icecube, Karen Andeen
Search For Astrophysical Sources Of Neutrinos Using Cascade Events In Icecube, Karen Andeen
Physics Faculty Research and Publications
The IceCube neutrino observatory has established the existence of a flux of high-energy astrophysical neutrinos, which is inconsistent with the expectation from atmospheric backgrounds at a significance greater than 5σ. This flux has been observed in analyses of both track events from muon neutrino interactions and cascade events from interactions of all neutrino flavors. Searches for astrophysical neutrino sources have focused on track events due to the significantly better angular resolution of track reconstructions. To date, no such sources have been confirmed. Here we present the first search for astrophysical neutrino sources using cascades interacting in IceCube with …
Vacuum Birefringence, The Photon Anomalous Magnetic Moment And The Neutron Star Rx J1856.5−3754, Sree Ram Valluri, J.W. Mielniczuk, Farrukh Chishtie, D. Lamm, S. Auddy
Vacuum Birefringence, The Photon Anomalous Magnetic Moment And The Neutron Star Rx J1856.5−3754, Sree Ram Valluri, J.W. Mielniczuk, Farrukh Chishtie, D. Lamm, S. Auddy
Physics and Astronomy Publications
We analyse the spectrum of the Hamiltonian of a photon propagating in a strong magnetic field B ∼ Bcr, where Bcr=m2e≃4.4×1013" role="presentation">Bcr=m2e≃4.4×1013 G is the Schwinger critical field. We show that the anomalous magnetic moment of a photon in the one-loop approximation is a non-decreasing function of the magnetic field B in the range 0 ≤ B ≤ 30 Bcr. We provide a numerical representation of the expression for the anomalous magnetic moment in terms of special functions. We find that the anomalous magnetic moment μγ of a photon for B = 30 B …
All-Sky Search For Time-Integrated Neutrino Emission From Astrophysical Sources With 7 Yr Of Icecube Data, Karen Andeen
All-Sky Search For Time-Integrated Neutrino Emission From Astrophysical Sources With 7 Yr Of Icecube Data, Karen Andeen
Physics Faculty Research and Publications
Since the recent detection of an astrophysical flux of high-energy neutrinos, the question of its origin has not yet fully been answered. Much of what is known about this flux comes from a small event sample of high neutrino purity, good energy resolution, but large angular uncertainties. In searches for point-like sources, on the other hand, the best performance is given by using large statistics and good angular reconstructions. Track-like muon events produced in neutrino interactions satisfy these requirements. We present here the results of searches for point-like sources with neutrinos using data acquired by the IceCube detector over 7 …
The Contribution Of Fermi-2lac Blazars To Diffuse Tev-Pev Neutrino Flux, Karen Andeen
The Contribution Of Fermi-2lac Blazars To Diffuse Tev-Pev Neutrino Flux, Karen Andeen
Physics Faculty Research and Publications
The recent discovery of a diffuse cosmic neutrino flux extending up to PeV energies raises the question of which astrophysical sources generate this signal. Blazars are one class of extragalactic sources which may produce such high-energy neutrinos. We present a likelihood analysis searching for cumulative neutrino emission from blazars in the 2nd Fermi-LAT AGN catalog (2LAC) using IceCube neutrino data set 2009-12, which was optimized for the detection of individual sources. In contrast to those in previous searches with IceCube, the populations investigated contain up to hundreds of sources, the largest one being the entire blazar sample in the …