Two Millisecond Pulsars Discovered by the PALFA Survey and a Shapiro Delay Measurement

J. S. Deneva (1) , P. C. C. Freire (2) , J. M. Cordes (3) , A. G. Lyne (4) , S. M. Ransom (5) , Ismaël Cognard (6, 7) , F. Camilo (1, 8) , D. J. Nice (9) , I. H. Stairs (10) , B. Allen (11) , N. D. R. Bhat (12) , S. Bogdanov (8) , A. Brazier (3) , D. J. Champion (2) , S. Chatterjee (3) , F. Crawford (13) , G. Desvignes (2) , J. W. T. Hessels (14) , F. A. Jenet (15) , V. M. Kaspi (16) , B. Knispel (11) , M. Kramer (2) , P. Lazarus (2) , J. van Leeuwen (14) , D. R. Lorimer (17) , R. S. Lynch (16) , M. A. Mclaughlin (17) , P. Scholz (16) , X. Siemens (18) , B. W. Stappers (4) , K. Stovall (15) , A. Venkataraman (1)

1 NAIC - Arecibo Observatory, National Astronomy and Ionosphere Center
2 MPIFR - Max-Planck-Institut für Radioastronomie
3 Department of Astronomy [Ithaca]
4 Jodrell Bank Centre for Astrophysics
5 NRAO - National Radio Astronomy Observatory
6 LPC2E - Laboratoire de Physique et Chimie de l'Environnement et de l'Espace
7 USN - Unité Scientifique de la Station de Nançay
8 CAL - Columbia Astrophysics Laboratory
9 Lafayette College [Easton]
10 Department of Physics and Astronomy, University of British Columbia
11 AEI - Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut )
12 Center for Astrophysics and Supercomputing
13 Department of Physics and Astronomy [Lancaster]
14 ASTRON - Netherlands Institute for Radio Astronomy
15 CGWA - Center for Gravitational Wave Astronomy
16 Department of Physics [Montréal]
17 Department of Physics, West Virginia University
18 Physics Department, University of Wisconsin at Milwaukee

We present two millisecond pulsar discoveries from the PALFA survey of the Galactic plane with the Arecibo telescope. PSR J1955+2527 is an isolated pulsar with a period of 4.87 ms, and PSR J1949+3106 has a period of 13.14 ms and is in a 1.9 day binary system with a massive companion. Their timing solutions, based on 4 years of timing measurements with the Arecibo, Green Bank, Nançay , and Jodrell Bank telescopes, allow precise determination of spin and astrometric parameters, including precise determinations of their proper motions. For PSR J1949+3106, we can clearly detect the Shapiro delay. From this we measure the pulsar mass to be 1.47 +0.43 −0.31 M , the companion mass to be 0.85 +0.14 −0.11 M , and the orbital inclination to be i = 79.9 −1.9 +1.6 deg, where uncertainties correspond to ±1σ confidence levels. With continued timing, we expect to also be able to detect the advance of periastron for the J1949+3106 system. This effect, combined with the Shapiro delay, will eventually provide very precise mass measurements for this system and a test of general relativity.

Domains: Sciences of the Universe [physics]; Astrophysics [astro-ph]; Physics [physics]

J. S. Deneva, P. C. C. Freire, J. M. Cordes, A. G. Lyne, S. M. Ransom, et al.. Two Millisecond Pulsars Discovered by the PALFA Survey and a Shapiro Delay Measurement. The Astrophysical Journal, 2012, 757 (1), 10 p. ⟨10.1088/0004-637X/757/1/89⟩. ⟨insu-01259503⟩