August 14, 2009 Journal article Open Access

A Population of Gamma-Ray Millisecond Pulsars Seen with the Fermi Large Area Telescope

Brian L Winer; B. Lott; Roger Blandford; M. L. Kocian; P. Weltevrede; Richard N. Manchester; M. N. Lovellette; M. Ziegler; A. Reimer; A. Reimer; Maura McLaughlin; J. Lande; A. Chekhtman; A. Chekhtman; Matthew Kerr; A. De Luca; L. Tibaldo; A. Tramacere; Francesco Longo; J. F. Ormes; Hartmut Sadrozinski; S. Cutini; T. Glanzman; Ronaldo Bellazzini; David Sánchez; Paulo C. C. Freire; P. M. Saz Parkinson; J. Bregeon; N. A. Webb; S. Germani; James Chiang; J. M. Casandjian; W. McConville; W. McConville; Hiromitsu Takahashi; Neil Gehrels; Neil Gehrels; T. H. Burnett; F. Loparco; W. B. Focke; E. Hays; Gregory Desvignes; Luca Latronico; Jean Ballet; Tyrel J. Johnson; Tyrel J. Johnson; Keith Bechtol; T. Reposeur; T. Ylinen; T. Ylinen; David S. Smith; Matthew G. Baring; Emanuele Bonamente; A. A. Abdo; Claudia Cecchi; Peter F. Michelson; L. Guillemot; M. Hayashida; Jeffrey D. Scargle; Charles D. Dermer; S. Rainò; M. Dormody; A. Makeev; A. Makeev; V. Pelassa; A. De Angelis; T. Ohsugi; Carmelo Sgrò; Riccardo Rando; J. H. Panetta; Johann Cohen-Tanugi; R. P. Johnson; Gudlaugur Johannesson; C. Meurer; A. S. Johnson; Tsunefumi Mizuno; George Hobbs; E. Orlando; I. A. Grenier; B. M. Baughman; Stephen E. Thorsett; E. Striani; Nicola Giglietto; P. Carlson; P. Carlson; Sylvain Guiriec; Ö. Çelik; V. Vasileiou; V. Vasileiou; Michael Kramer; Paul J. Wang; Robin H. D. Corbet; Robin H. D. Corbet; P. Lubrano; F. de Palma; Persis S. Drell; G. Theureau; Christo Venter; Christo Venter; Dario Gasparrini; Alice K. Harding; D. J. Thompson; David Paneque; E. Wallace; Marco Ajello; R. A. Cameron; Y. Edmonds; G.L. Godfrey; M. Brigida; W. Mitthumsiri; B. Berenji; A. Y. Rodriguez; Julie McEnery; M. Lemoine-Goumard; C. Favuzzi; Felix Ryde; Felix Ryde; Scott M. Ransom; V. Vitale; P. A. Caraveo; Marco Frailis; Nicola Omodei; R. Claus; T. Kamae; J. E. Grove; M. Marelli; P. Spinelli; H. Tajima; M. Razzano; L.S. Rochester; Jun Kataoka; Diego F. Torres; G. A. Caliandro; C. C. Cheung; J. G. Thayer; E. Charles; D. Dumora; N. Kawai; K. S. Wood; Denis Bastieri; A. W. Borgland; W. N. Johnson; Ismaël Cognard; Hideaki Katagiri; E. J. Siskind; Elliott D. Bloom; Y. Hanabata; Jean-Luc Starck; S. Murgia; F. Piron; M. N. Mazziotta; J. B. Thayer; M. Pepe; L. R. Cominsky; Yasunobu Uchiyama; Markus Ackermann; Karen Watters; Yasushi Fukazawa; M. Roth; T. Schalk; Stefano Ciprini; Roger W. Romani; A. Sander; Benjamin Stappers; P. D. Smith; A. A. Moiseev; A. A. Moiseev; E. Nuss; E. Do Couto E Silva; R. E. Hughes; B. Giebels; A. P. Waite; Simon Johnston; Grzegorz Madejski; C. Farnier; A. van Etten; D. J. Suson; S. Ritz; Jürgen Knödlseder; A. Brez; A. Morselli; Olaf Reimer; Olaf Reimer; Luca Baldini; Guido Barbiellini; T. L. Usher; P. Fusco; Magnus Axelsson; Pascal Bruel; M. S. Strickman; Fernando Camilo; F. Giordano; Seth Digel; G. Tosti; Paul S. Ray; T. A. Porter; J. P. Norris; P. L. Nolan; M. Kuss; F. Gargano

Gamma-Ray Pulsar Bonanza Most of the pulsars we know about were detected through their radio emission; a few are known to pulse gamma rays but were first detected at other wavelengths (see the Perspective by Halpern ). Using the Fermi Gamma-Ray Space Telescope, Abdo et al. (p. 840 , published online 2 July; see the cover) report the detection of 16 previously unknown pulsars based on their gamma-ray emission alone. Thirteen of these coincide with previously unidentified gamma-ray sources, solving the 30-year-old mystery of their identities. Pulsars are fast-rotating neutron stars. With time they slow down and cease to radiate; however, if they are in a binary system, they can have their spin rates increased by mass transfer from their companion stars, starting a new life as millisecond pulsars. In another study, Abdo et al. (p. 845 ) report the detection of gamma-ray emission from the globular cluster 47 Tucanae, which is coming from an ensemble of millisecond pulsars in the cluster's core. The data imply that there are up to 60 millisecond pulsars in 47 Tucanae, twice as many as predicted by radio observations. In a further companion study, Abdo et al. (p. 848 , published online 2 July) searched Fermi Large Area Telescope data for pulsations from all known millisecond pulsars outside of stellar clusters, finding gamma-ray pulsations for eight of them. Their properties resemble those of other gamma-ray pulsars, suggesting that they share the same basic emission mechanism. Indeed, both sets of pulsars favor emission models in which the gamma rays are produced in the outer magnetosphere of the neutron star.