2014/02/10 by Yuanjie Du, Jun Yang, R. M. Campbell +6 · 23 citations
Physics and Astronomy · #Astrometry #Astronomy #Astrophysics #Astrophysics and Cosmic Phenomena #Galaxy #Luminosity #Millisecond pulsar #Parallax #Physics #Proper motion #Pulsar #Pulsars and Gravitational Waves Research #Quasar #Radio Astronomy Observations and Technology #Stars #Very Long Baseline Array #Very-long-baseline interferometry #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.1088/2041-8205/782/2/l38
published in The Astrophysical Journal Letters 782(2), L38 (IOP Publishing) · 5 pages, 2 figures, 2 tables; published in the Astrophysical Journal Letters on 2014 Feb. 10
openalex publication_date 2014/02/10 · arxiv created 2014/02/11 · arxiv updated 2014/02/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
PSR J0218+4232 is a millisecond pulsar (MSP) with a flux density ∼0.9 mJy at 1.4 GHz. It is very bright in the high-energy X-ray and γ-ray domains. We conducted an astrometric program using the European VLBI Network (EVN) at 1.6 GHz to measure its proper motion and parallax. A model-independent distance would also help constrain its γ-ray luminosity. We achieved a detection of signal-to-noise ratio S/N >37 for the weak pulsar in all five epochs. Using an extragalactic radio source lying 20 arcmin away from the pulsar, we estimate the pulsar's proper motion to be μ α cos δ = 5.35 ± 0.05 mas yr −1 and μ δ = −3.74 ± 0.12 mas yr −1 , and a parallax of π = 0.16 ± 0.09 mas. The very long baseline interferometry (VLBI) proper motion has significantly improved upon the estimates from long-term pulsar timing observations. The VLBI parallax provides the first model-independent distance constraints: kpc, with a corresponding 3σ lower-limit of d = 2.3 kpc. This is the first pulsar trigonometric parallax measurement based solely on EVN observations. Using the derived distance, we believe that PSR J0218+4232 is the most energetic γ-ray MSP known to date. The luminosity based on even our 3σ lower-limit distance is high enough to pose challenges to the conventional outer gap and slot gap models.