Microlensing Neutron Stars

Abstract

We investigate the chances that neutron stars act as the lense in a gravitational microlensing event towards the galactic bulge or a spiral arm. The observation of neutron stars by means of gravitational microlensing would allow the estimation of neutron star masses independently of the property of being a pulsar in a binary system. We estimate the contribution of neutron stars to the optical depth and the lensing rate based on two different models of the pulsar distribution in the galaxy. Since only a small fraction of all neutron stars are pulsars, it is unlikely to find a pulsar that acts as a microlense by chance. A position comparison of known radio pulsars with observed microlensing candidates towards the galactic bulge and spiral arms shows no candidate pair, which is consistent with the theoretical expectation. To improve the probability of microlensing a pulsar, we suggest to search for gravitational microlensing events of known nearby high proper motion pulsars. The pulsar PSR J1932+1059 is a good candidate for an astrometric detection of gravitational lensing.

9 pages, 7 figures, includes note added in proof, A&A in press

References in corpus (4)

• GAIA: Composition, Formation and Evolution of the Galaxy
• The Parkes Multibeam Pulsar Survey: I. Observing and Data Analysis Systems, Discovery and Timing of 100 Pulsars
• The Swinburne Intermediate Latitude Pulsar Survey
• Resolving gravitational microlensing events with long-baseline optical interferometry. Prospects for the ESO Very Large Telescope Interferometer

Cited by in corpus (6)

• Revisiting the radial distribution of pulsars in the Galaxy
• Gravitational Microlensing by Neutron Stars and Radio Pulsars: Event Rates, Timescale Distributions, and Mass Measurements
• Peccei-Quinn axions from frequency dependence radiation dimming
• Natal kicks of compact objects
• Microlensing pulsars
• Astrometric microlensing probes of the isolated neutron star population with Roman