Einstein@Home aggregates the computer power of hundreds of thousands of volunteers from 193 countries, to search for new neutron stars using data from electromagnetic and gravitational-wave detectors. This paper presents a detailed description of the search for new radio pulsars using Pulsar ALFA survey data from the Arecibo Observatory. The enormous computing power allows this search to cover a new region of parameter space; it can detect pulsars in binary systems with orbital periods as short as 11 minutes. We also describe the first Einstein@Home discovery, the 40.8 Hz isolated pulsar PSR J2007+2722, and provide a full timing model. PSR J2007+2722's pulse profile is remarkably wide with emission over almost the entire spin period. This neutron star is most likely a disrupted recycled pulsar, about as old as its characteristic spin-down age of 404 Myr. However, there is a small chance that it was born recently, with a low magnetic field. If so, upper limits on the X-ray flux suggest but cannot prove that PSR J2007+2722 is at least ~100 kyr old. In the future, we expect that the massive computing power provided by volunteers should enable many additional radio pulsar discoveries.
"The Einstein@Home Search for Radio Pulsars and PSR J2007+2722" B. Allen, B. Knispel, J. M. Cordes, J. S. Deneva, J. W. T. Hessels, D. Anderson, C. Aulbert, O. Bock, A. Brazier, S. Chatterjee, P. B. Demorest, H. B. Eggenstein, H. Fehrmann, E. V. Gotthelf, D. Hammer, V. M. Kaspi, M. Kramer, A. G. Lyne, B. Machenschalk, M. A. McLaughlin, C. Messenger, H. J. Pletsch, S. M. Ransom, I. H. Stairs, B. W. Stappers, N. D. R. Bhat, S. Bogdanov, F. Camilo, D. J. Champion, F. Crawford, G. Desvignes, P. C. C. Freire, G. Heald, F. A. Jenet, P. Lazarus, K. J. Lee, J. van Leeuwen, R. Lynch, M. A. Papa, R. Prix, R. Rosen, P. Scholz, X. Siemens, K. Stovall, A. Venkataraman, & W. Zhu, Astrophysical Journal, 773, 91 (2013).