Discovery of millisecond pulsars in radio searches of southern Fermi LAT sources
| Autor: | Keith, M. J., Johnston, S., Ray, P. S., Ferrara, E. C., Parkinson, P. M. Saz, Celik, O., Belfiore, A., Donato, D., Cheung, C. C., Abdo, A. A., Camilo, F., Freire, P. C. C., Guillemot, L., Harding, A. K., Kramer, M., Michelson, P. F., Ransom, S. M., Romani, R. W., Smith, D. A., Thompson, D. J., Weltevrede, P., Wood, K. S. |
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| Rok vydání: | 2011 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1111/j.1365-2966.2011.18464.x |
| Popis: | Using the Parkes radio telescope we have carried out deep observations of eleven unassociated gamma-ray sources. Periodicity searches of these data have discovered two millisecond pulsars, PSR J1103-5403 (1FGL J1103.9-5355) and PSR J2241-5236 (1FGL J2241.9-5236), and a long period pulsar, PSR J1604-44 (1FGL J1604.7-4443). In addition we searched for but did not detect any radio pulsations from six gammaray pulsars discovered by the Fermi satellite to a level of - 0.04 mJy (for pulsars with a 10% duty cycle). Timing of the millisecond pulsar PSR J1103-5403 has shown that its position is 9' from the centroid of the gamma-ray source. Since these observations were carried out, independent evidence has shown that 1FGL J1103.9-5355 is associated with the flat spectrum radio source PKS 1101-536. It appears certain that the pulsar is not associated with the gamma-ray source, despite the seemingly low probability of a chance detection of a radio millisecond pulsar. We consider that PSR J1604-44 is a chance discovery of a weak, long period pulsar and is unlikely to be associated with 1FGL J1604.7-4443. PSR J2241-5236 has a spin period of 2.2 ms and orbits a very low mass companion with a 3.5 hour orbital period. The relatively high flux density and low dispersion measure of PSR J2241-5236 makes it an excellent candidate for high precision timing experiments. The gamma-rays of 1FGL J2241.9-5236 have a spectrum that is well modelled by a power law with exponential cutoff, and phasebinning with the radio ephemeris results in a multi-peaked gamma-ray pulse profile. Observations with Chandra have identified a coincident X-ray source within 0.1" of the position of the pulsar obtained by radio timing Comment: 9 Pages 6 Figures, for publication in MNRAS |
| Databáze: | arXiv |
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