title: Statistics of clustering of ultrahigh energy cosmic rays and the number of their sources.
abstract: Observation of clustering of ultrahigh energy cosmic rays (UHECR) suggests that they are emitted by compact sources. Assuming small ( <3 degrees ) deflection of UHECR during the propagation, the statistical analysis of clustering allows an estimate of the spatial density of the sources h(*), including those not yet observed. When applied to astrophysical models involving extragalactic sources, the estimate based on 14 events with energy E>10(20) eV gives h(*) approximately 6x10(-3) Mpc(-3). With increasing statistics, this estimate may lead to exclusion of some models.
authors.affiliation: Institute for Nuclear Research, 60th October Anniversary prospect 7a, 117312 Moscow, Russia.
authors.forename: S L
authors.initials: SL
authors.lastname: Dubovsky
authors.forename: P G
authors.initials: PG
authors.lastname: Tinyakov
authors.forename: I I
authors.initials: II
authors.lastname: Tkachev
mesh_terms: D055580:Astronomical Phenomena; D001256:Astronomy; D003359:Cosmic Radiation; D015233:Models, Statistical