Abstract The X-ray pulsar GX 1+4 was observed during a balloon flight from Alice Springs, Australia on November 20, 1986. Significant flux was detected over the full energy range of the detector (15 – 114 keV). The spectrum was very hard with a photon power law index of 1.9 ± 0.2. The intensity at 30 keV was (5.1±0.2) × 10−4 cm−2s−1keV−1; a factor of ∼ 3 less than typical during the 1970's but orders of magnitude greater than during recent satellite measurements. The pulse profiles below ∼ 75 keV were very broad with indications of a notch at the peak. At higher energies there was a remarkable change with a narrow pulse of phase width ∼ 0.2 centred on the phase of the lower energy notch. We believe this to be the first observation of phase reversals in pulse profiles in the hard X-ray energy range. The observational evidence can be explained within the framework of a model based on two-photon emission as the dominant continuum source. This requires a magnetic field ∼ 2 × 1013 gauss — a value consistent with accretion models in which the system has a retrograde disc.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Energy spectrum and pulse profiles of the binary pulsar GX 1 + 4


    Contributors:
    Dieters, S.W.B. (author) / Greenhill, J.G. (author) / Sharma, D.P. (author) / Sood, R.K. (author) / Waldron, L. (author) / Storey, M.C. (author)

    Published in:

    Publication date :

    1991-01-01


    Size :

    5 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Fast time-delay measurement for integrated pulsar pulse profiles

    Kang, Zhiwei / He, Xin / Liu, Jin et al. | Emerald Group Publishing | 2017


    The double-pulsar binary J0737-3039

    Lyne, A. G. / COSPAR | British Library Conference Proceedings | 2006


    The double-pulsar binary J0737–3039

    Lyne, A.G. | Online Contents | 2006



    HST imaging of the binary pulsar PSR1913+16

    Crane, P. | British Library Online Contents | 1992