VLT polarimetry observations of the middle-aged pulsar PSR B0656+14
Abstract
Context. Optical polarisation measurements are key tests for different models of the pulsar magnetosphere. Furthermore, comparing the relative orientation of the phase-averaged linear polarisation direction and the pulsar proper motion vector may unveil a peculiar alignment, clearly seen in the Crab pulsar.
Aims: Our goal is to obtain the first measurement of the phase-averaged optical linear polarisation of the fifth brightest optical pulsar, PSR B0656+14, which also has a precisely measured proper motion, and to verify a possible alignment between the polarisation direction and the proper motion vector.
Methods: We carried out observations with the Very Large Telescope (VLT) to measure the phase-averaged optical polarisation degree (PD) and position angle (PA) of PSR B0656+14.
Results: We measured a PD of 11.9% ± 5.5% and a PA of 125.8° ± 13.2°, measured east of north. Albeit of marginal significance, this is the first measurement of the phase-averaged optical PD for this pulsar. Moreover, we found that the PA of the phase-averaged polarisation vector is close to that of the pulsar proper motion (93.12° ± 0.38°).
Conclusions: Deeper observations are needed to confirm our polarisation measurement of PSR B0656+14, whereas polarisation measurements for more pulsars will better assess possible correlations of the polarisation degree with the pulsar parameters.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- November 2015
- DOI:
- 10.1051/0004-6361/201527082
- arXiv:
- arXiv:1510.01057
- Bibcode:
- 2015A&A...583A.105M
- Keywords:
-
- pulsars: individual: PSR B0656+14;
- pulsars: general;
- polarization;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 5 pages, 7 figures, accepted for publication on Astronomy &