Astron. Astrophys. 348, 519-523 (1999)

Timing and spectral properties of PSR B0540-69 observed with BeppoSAX

T. Mineo ¹, G. Cusumano ¹, E. Massaro ², L. Nicastro ¹, A.N. Parmar ³ and B. Sacco <sup>1

1</sup> Istituto di Fisica Cosmica ed Applicazioni all'Informatica CNR, Via U. La Malfa 153, I-90146 Palermo, Italy
² Istituto Astronomico, Unita' GIFCO Roma-1, Universita' "La Sapienza", Via Lancisi 29, I-00161 Roma, Italy
³ Astrophysics Division, Space Science Department of ESA, ESTEC, Post box 299, 2200 AG Noordwijk, The Netherlands

Received 4 November 1998 / Accepted 25 January 1999

Abstract

BeppoSAX observed PSR B0540-69 on 1996 October 25-26 during the Science Verification Phase. The pulsar, detected by the imaging LECS and MECS instruments (0.1-10 keV), shows a characteristic nearly sinusoidal pulse structure with a minor structure on the left side of the maximum. By combining the BeppoSAX measurements with earlier ASCA results we derived a low value of the braking index of . We also investigate the X-ray spectral distribution of the pulsed emission in the energy band (2-10) keV. We find that it can be well represented by a single absorbed power-law with energy index of and cm^-2.

Key words: stars: neutron stars: pulsars: general stars: pulsars: individual: PSR B0540-69 X-rays: stars

Send offprint requests to: T. Mineo (mineo@ifcai.pa.cnr.it)

© European Southern Observatory (ESO) 1999

Online publication: July 26, 1999

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