A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
NuSTAR observations of the supergiant X-ray pulsar IGR J18027-2016: accretion from the stellar wind and possible cyclotron absorption line
Tekijät: Lutovinov AA, Tsygankov SS, Postnov KA, Krivonos RA, Molkov SV, Tomsick JA
Kustantaja: OXFORD UNIV PRESS
Julkaisuvuosi: 2017
Journal: Monthly Notices of the Royal Astronomical Society
Tietokannassa oleva lehden nimi: MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Lehden akronyymi: MON NOT R ASTRON SOC
Vuosikerta: 466
Numero: 1
Aloitussivu: 593
Lopetussivu: 599
Sivujen määrä: 7
ISSN: 0035-8711
DOI: https://doi.org/10.1093/mnras/stw3058
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/20667125
We report on the first focused hard X-ray view of the absorbed supergiant system IGR J18027-2016 performed with the Nuclear Spectroscopic Telescope Array observatory. The pulsations are clearly detected with a period of P-spin = 139.866(1)s and a pulse fraction of about 50-60 per cent at energies from 3 to 80 keV. The source demonstrates an approximately constant X-ray luminosity on a time-scale of more than dozen years with an average spin-down rate of P similar or equal to 6 x 10(-10) s s(-1). This behaviour of the pulsar can be explained in terms of the wind accretion model in the settling regime. The detailed spectral analysis at energies above 10 keV was performed for the first time and revealed a possible cyclotron absorption feature at energy similar to 23 keV. This energy corresponds to the magnetic field B similar or equal to 3 x 10(12) G at the surface of the neutron star, which is typical for X-ray pulsars.
Ladattava julkaisu This is an electronic reprint of the original article. |  |
