Abstract The gamma-ray emission of Geminga during five COS-B observations has been analysed to derive its spectral properties between 50 MeV and 5 GeV. In all observations but one, the spectrum presents a turnover between 100 and 200 MeV, the source becoming very weak at the lowest gamma- ray energies. During the remaining observation, the spectrum is consistent with a power-law spectrum with index −2.02 ± 0.10 over the whole energy range. So, Geminga exhibits long-term variability for energies below 200 MeV. Very similar spectral properties and variability have been found for one component of the Vela pulsar lightcurve, providing new evidence that Geminga might be a Vela-type pulsar.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    The variable energy-distribution of the gamma-ray emission from Geminga


    Contributors:
    Grenier, I.A. (author) / Hermsen, W. (author) / Hote, C. (author)

    Published in:

    Advances in Space Research ; 11 , 8 ; 107-110


    Publication date :

    1991-01-01


    Size :

    4 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Geminga pulsar observations with gamma-telescope Gamma-1

    Akimov, V.V. / Afanassyev, V.G. / Blokhintsev, I.D. et al. | Elsevier | 1993


    Geminga Pulsar Observations with Gamma-Telescope Gamma-1

    Akimov, V. V. / Afanassyev, V. G. / Blokhintsev, I. D. et al. | British Library Conference Proceedings | 1993



    The neutral gas in the environs of the Geminga gamma-ray pulsar

    Giacani, E. / Reynoso, E. M. / Dubner, G. et al. | British Library Conference Proceedings | 2005


    Einstein and EXOSAT observations of Geminga revisited

    Mereghetti, S. / Caraveo, P. / Bignami, G.F. | Elsevier | 1993