Title: Discovery of millisecond pulsars in radio searches of southern Fermi Large Area Telescope sources

Abstract

Using the Parkes Radio Telescope, we have carried out deep observations of 11 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 gamma-ray pulsars discovered by the Fermi satellite to a level of ~0.04 mJy (for pulsars with a 10 per cent duty cycle). The timing of the millisecond pulsar PSR J1103–5403 has shown that its position is 9 arcmin 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-h orbital period. The relatively high fluxmore » density and low dispersion measure of PSR J2241–5236 make 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 an exponential cut-off, and phase binning with the radio ephemeris results in a multipeaked gamma-ray pulse profile. Furthermore, observations with Chandra have identified a coincident X-ray source within 0.1 arcsec of the position of the pulsar obtained by radio timing.« less

Authors:

Keith, M. J. ^[1]; Johnston, S. ^[1]; Ray, P. S. ^[2]; Ferrara, E. C. ^[3]; Saz Parkinson, P. M. ^[4]; Çelik, Ö. ^[5]; Belfiore, A. ^[6]; Donato, D. ^[7]; Cheung, C. C. ^[8]; Abdo, A. A. ^[8]; Camilo, F. ^[9]; Freire, P. C. C. ^[10]; Guillemot, L. ^[10]; Harding, A. K. ^[3]; Kramer, M. ^[11]; Michelson, P. F. ^[12]; Ransom, S. M. ^[13]; Romani, R. W. ^[12]; Smith, D. A. ^[14]; Thompson, D. J. ^[3] more »; Weltevrede, P. ^[15]; Wood, K. S. ^[2] « less

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+ Show Author Affiliations

1. Australia Telescope National Facility, Epping, NSW (Australia)
2. Naval Research Lab., Washington, D.C. (United States)
3. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
4. Univ. of California, Santa Cruz, CA (United States)
5. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland Baltimore County (UMBC), Baltimore, MD (United States)
6. Univ. of California, Santa Cruz, CA (United States); INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, Milano (Italy); Univ. di Pavia, Pavia (Italy)
7. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States)
8. National Academy of Sciences, Washington, D.C. (United States); Naval Research Lab., Washington, D.C. (United States)
9. Columbia Univ., New York, NY (United States)
10. Max-Planck-Institut fur Radioastronomie, Bonn (Germany)
11. Max-Planck-Institut fur Radioastronomie, Bonn (Germany); The Univ. of Manchester, Manchester (United Kingdom)
12. Stanford Univ., Stanford, CA (United States)
13. National Radio Astronomy Observatory (NRAO), Charlottesville, VA (United States)
14. Univ. Bordeaux, Gradignan (France)
15. The Univ. of Manchester, Manchester (United Kingdom)

Publication Date:

Wed Jun 08 00:00:00 EDT 2011

Research Org.:

SLAC National Accelerator Lab., Menlo Park, CA (United States)

Sponsoring Org.:

USDOE

OSTI Identifier:

1357255

Grant/Contract Number:  

AC02-76SF00515

Resource Type:

Accepted Manuscript

Journal Name:

Monthly Notices of the Royal Astronomical Society

Additional Journal Information:

Journal Volume: 414; Journal Issue: 2; Journal ID: ISSN 0035-8711

Publisher:

Royal Astronomical Society

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; pulsars: general; pulsars: individual: J2241−5236