Search for the elusive optical counterpart of PSR J0537–6910 with the HST Advanced Camera for Surveys

¹ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany e-mail: rmignani@eso.org
² INAF - Osservatorio Astronomico di Roma, Via di Frascati 33, 00040 Monte Porzio Catone, Italy e-mail: [pulone;giacinto]@mporzio.astro.it
³ Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA e-mail: [pavlov;townsley;green]@astro.psu.edu

Received: 3 August 2004
Accepted: 25 October 2004

Abstract

We present the results of deep, high-resolution, multi-band optical observations of the field of the young ( yr) 16 ms X-ray pulsar PSR J0537-6910 performed with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST). Although a few new potential counterparts have been detected within or close to the revised Chandra X-ray error circle () of the pulsar, only two of them (with magnitudes and ) show indications of a peculiar spectrum which could be related to optical emission from the pulsar. This might be true also for a third, fainter, candidate detected only in one filter (with magnitude ). If either of the two brighter candidates is indeed the actual counterpart, the optical output of PSR J0537-6910 would make it similar to young Crab-like pulsars. If not, it would mean that PSR J0537-6910 is significantly underluminous with respect to all pulsars detected in the optical.