A search for the optical counterpart to PSR B1821-24 in M 28

A. Golden, R. F. Butler, A. Shearer

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

We have analysed archival HST/WFPC2 images in both the F555W & F814W bands of the core field of the globular cluster M 28 in an attempt to identify the optical counterpart of the magnetospherically active millisecond pulsar PSR B1821-24. Examination of the radio derived error circle yielded several potential candidates, down to a magnitude of V ∼ 24.5 (V0 ∼ 23.0). Each were further investigated, both in the context of the CMD of M 28, and also with regard to phenomenological models of pulsar magnetospheric emission. The latter was based on both luminosity-spindown correlations and known spectral flux density behaviour in this regime from the small population of optical pulsars observed to date. None of the potential candidates exhibited emission expected from a magnetospherically active pulsar. The fact that the magnetic field & spin coupling for PSR B1821-24 is of a similar magnitude to that of the Crab pulsar in the vicinity of the light cylinder has suggested that the millisecond pulsar may well be an efficient nonthermal emitter. ASCA's detection of a strong synchrotron-dominated X-ray pulse fraction encourages such a viewpoint. We argue that only future dedicated 2-d high speed photometry observations of the radio error-circle can finally resolve this matter.

Original languageEnglish (US)
Pages (from-to)198-204
Number of pages7
JournalAstronomy and Astrophysics
Volume371
Issue number1
StatePublished - May 2001
Externally publishedYes

Fingerprint

pulsars
radio
crab
magnetic field
crabs
globular clusters
photometry
synchrotrons
emitters
flux density
examination
luminosity
high speed
pulses
magnetic fields
detection
speed
x rays

Keywords

  • Astrometry
  • Globular clusters: general
  • Globular clusters: individual M 28/NGC 6626
  • Pulsars: general
  • Pulsars: individual PSR B1821-24
  • Techniques: image processing

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Golden, A., Butler, R. F., & Shearer, A. (2001). A search for the optical counterpart to PSR B1821-24 in M 28. Astronomy and Astrophysics, 371(1), 198-204.

A search for the optical counterpart to PSR B1821-24 in M 28. / Golden, A.; Butler, R. F.; Shearer, A.

In: Astronomy and Astrophysics, Vol. 371, No. 1, 05.2001, p. 198-204.

Research output: Contribution to journalArticle

Golden, A, Butler, RF & Shearer, A 2001, 'A search for the optical counterpart to PSR B1821-24 in M 28', Astronomy and Astrophysics, vol. 371, no. 1, pp. 198-204.
Golden A, Butler RF, Shearer A. A search for the optical counterpart to PSR B1821-24 in M 28. Astronomy and Astrophysics. 2001 May;371(1):198-204.
Golden, A. ; Butler, R. F. ; Shearer, A. / A search for the optical counterpart to PSR B1821-24 in M 28. In: Astronomy and Astrophysics. 2001 ; Vol. 371, No. 1. pp. 198-204.
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