Neutrons travel on straight lines, undeflected by magnetic fields, and they produce air showers that are indistinguishable from air showers produced by protons. A flux of neutrons from a discrete source would cause an excess of cosmic-ray events around the direction to the source, clustered within the angular resolution of the observatory. Since free neutrons undergo beta decay with a mean lifetime of about 886 s at rest (Particle Data Group 2010), the mean travel distance for relativistic neutrons is 9.2 × E kpc, where E is the energy of the neutron in EeV (1 EeV = 1018 eV). The distance from Earth to the Galactic center is about 8.3 kpc (Gillessen 2009), and the radius of the Galaxy is approximately 15 kpc. Sources in part of the Galactic disk, including the Galactic center, should be detectable via neutrons above 1 EeV. Above 2 EeV, the volume for detectable neutron emitters includes most of the Galaxy.

A SEARCH FOR POINT SOURCES OF EeV NEUTRONS / P., A., M., A., M., A., E. J., A., I. F. M., A., D., A., I., A., J., A., P., A., A., A., J., A.C., J., A.M., R., A.B., M., A., A., A., L., A., S., A., T., A., Aramo, C., E., A., et al.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 760:(2012), pp. 148-159. [10.1088/0004-637X/760/2/148]

A SEARCH FOR POINT SOURCES OF EeV NEUTRONS

ARAMO, CARLA;CILMO, MARCO;D'URSO, DOMENICO;GUARINO, FAUSTO;VALORE, LAURA;
2012

Abstract

Neutrons travel on straight lines, undeflected by magnetic fields, and they produce air showers that are indistinguishable from air showers produced by protons. A flux of neutrons from a discrete source would cause an excess of cosmic-ray events around the direction to the source, clustered within the angular resolution of the observatory. Since free neutrons undergo beta decay with a mean lifetime of about 886 s at rest (Particle Data Group 2010), the mean travel distance for relativistic neutrons is 9.2 × E kpc, where E is the energy of the neutron in EeV (1 EeV = 1018 eV). The distance from Earth to the Galactic center is about 8.3 kpc (Gillessen 2009), and the radius of the Galaxy is approximately 15 kpc. Sources in part of the Galactic disk, including the Galactic center, should be detectable via neutrons above 1 EeV. Above 2 EeV, the volume for detectable neutron emitters includes most of the Galaxy.
2012
A SEARCH FOR POINT SOURCES OF EeV NEUTRONS / P., A., M., A., M., A., E. J., A., I. F. M., A., D., A., I., A., J., A., P., A., A., A., J., A.C., J., A.M., R., A.B., M., A., A., A., L., A., S., A., T., A., Aramo, C., E., A., et al.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - 760:(2012), pp. 148-159. [10.1088/0004-637X/760/2/148]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/533851
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