A VLBI distance and transverse velocity for PSR B1913+16

Nice, David J.; Weisberg, J. M.; Deller, A. T.; Chatterjee, S.

A VLBI distance and transverse velocity for PSR B1913+16

Abstract

Using the Very Long Baseline Array, we have made astrometric observations of the binary pulsar B1913+16 spanning an 18-month period in 2014-2015. From these observations we make the first determination of the annual geometric parallax of B1913+16, measuring pi = 0.24(-0.08)(+0.68) mas (68% confidence interval). The inferred parallax probability distribution differs significantly from a Gaussian. Using our parallax measurement and prior information on the spatial and luminosity distributions of the millisecond pulsar population, we infer a distance of d = 4.1(-0.7)( )(+2.0)kpc, which is significantly closer than the 9.8 +/- 3.1 kpc suggested by the pulsar's dispersion measure (DM) and analyses of the ionized interstellar medium. While the relatively low significance of the parallax detection (similar to 3 sigma) currently precludes an improved test of general relativity using the orbital decay of PSR B1913 +16, ongoing observations with improved control of systematic astrometric errors could reach the 10% distance uncertainty required for this goal. The proper motion measured by our Very Long Baseline Interferometry astrometry differs substantially from that obtained by pulsar timing, a discrepancy that has also been found between the proper motion measurements made by interferometers and pulsar timing for some other pulsars, which we speculate is the result of timing noise or DM variations in the timing data set. Our parallax and proper motion measurements yield a transverse velocity of 15(-)(4)( )(+8)km s(-1) in the solar reference frame. Analysis incorporating galactic rotation and solar motion finds that the space velocity of the pulsar relative to its standard of rest has a component 22(-)(3)( )(+7)km s(-1) perpendicular to the galactic plane and components on the order of 100 km s(-1) parallel to the galactic plane.

Title	A VLBI distance and transverse velocity for PSR B1913+16
Creator	Nice, David J.
	Weisberg, J. M.
	Deller, A. T.
	Chatterjee, S.
Publisher	Astrophysical Journal
Academic Department	Physics
Division	Natural Sciences
Organization	Lafayette College
Date Issued	August 2018
Date Available	2018-08-22T20:28:31Z
Type	Article
Language	English
Keyword	pulsars: individual (PSR B1913+16)
	techniques: high angular resolution
	gravitation
	astrometry
	stars: neutron
Bibliographic Citation	Deller, A. T., et al. (2018 Aug.) "A VLBI distance and transverse velocity for PSR B1913+16." Astrophysical Journal 862 (2): Article 139.
Standard Identifier	DOI 10.3847/1538-4357/aacf95
Standard Identifier	Handle 10385/2426
Permalink	http://hdl.handle.net/10385/2426
Rights Statement	In Copyright
Rights Holders	The American Astronomical Society