Astron. Astrophys. 343, L15-L18 (1999)

Letter to the Editor

Deep optical observations at the position of PSR1706-44 with the VLT-UT1 ^*

Peter Lundqvist ¹, Jesper Sollerman ¹, Alak Ray ², Bruno Leibundgut ³ and Firoza Sutaria <sup>4

1</sup> Stockholm Observatory, SE-133 36 Saltsjöbaden, Sweden
² Tata Institute of Fundamental Research, Bombay 400 005, India
³ European Southern Observatory, D-85748 Garching bei München, Germany
⁴ Inter University Centre for Astronomy and Astrophysics, Pune 411 007, India

Received 23 November 1998 / Accepted 4 December 1998

Abstract

We present optical data gathered by the VLT Test Camera in the V -band at the radio (interferometric) position of PSR1706-44. We find no optical counterpart to the pulsar in the VLT image. At a distance of 2:007 from a nearby bright star, the 3 upper limit to the pulsar magnitude above the background is . Within an error circle of 1:000 the upper limit is degraded in the direction towards the star. At a distance from the star we can with confidence only claim an upper limit of . This is still several magnitudes fainter than previous estimates. The implications of the optical upper limit taken together with the high energy pulsed gamma-ray radiation for theoretical models of pulsar emission are discussed.

Key words: stars: pulsars: individual: PSR1706-44 telescopes stars: pulsars: general

* Based on observations collected at the European Southern Observatory, Paranal, Chile (VLT-UT1 Science Verification Program)

Correspondence to: peter@astro.su.se

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and results
• 3. Discussion and conclusion
• Acknowledgements
• References

© European Southern Observatory (ESO) 1999

Online publication: March 1, 1999
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