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@Article{CoelhoCáLiMaRuRu:2017:RoNaSo,
               author = "Coelho, Jaziel Goulart and C{\'a}ceres, D. L. and Lima, R. C. R. 
                         and Malheiro, M. and Rueda, J. A. and Ruffini, R.",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Sapienza 
                         Universit{\`a} di Roma} and ICRANet and {Instituto 
                         Tecnol{\'o}gico de Aeron{\'a}utica (ITA)} and {Sapienza 
                         Universit{\`a} di Roma} and {Sapienza Universit{\`a} di Roma}",
                title = "The rotation-powered nature of some soft gamma-ray repeaters and 
                         anomalous X-ray pulsars",
              journal = "Astronomy and Astrophysics",
                 year = "2017",
               volume = "599",
               number = "A87",
                month = "Mar.",
             keywords = "pulsars: general, stars: rotation, stars: neutron, stars: magnetic 
                         field.",
             abstract = "Context. Soft gamma-ray repeaters (SGRs) and anomalous X-ray 
                         pulsars (AXPs) are slow rotating isolated pulsars whose energy 
                         reservoir is still matter of debate. Adopting neutron star (NS) 
                         fiducial parameters; mass M = 1 : 4 M-circle dot, radius R = 10 
                         km, and moment of inertia, I = 1045 g cm(2), the rotational energy 
                         loss,. E-rot, is lower than the observed luminosity (dominated by 
                         the X-rays) L-X for many of the sources. Aims. We investigate the 
                         possibility that some members of this family could be canonical 
                         rotation-powered pulsars using realistic NS structure parameters 
                         instead of fiducial values. Methods. We compute the NS mass, 
                         radius, moment of inertia and angular momentum from numerical 
                         integration of the axisymmetric general relativistic equations of 
                         equilibrium. We then compute the entire range of allowed values of 
                         the rotational energy loss,. E-rot, for the observed values of 
                         rotation period P and spin-down rate. P. We also estimate the 
                         surface magnetic field using a general relativistic model of a 
                         rotating magnetic dipole. Results. We show that realistic NS 
                         parameters lowers the estimated value of the magnetic field and 
                         radiation efficiency, LX/Erot, with respect to estimates based on 
                         fiducial NS parameters. We show that nine SGRs/AXPs can be 
                         described as canonical pulsars driven by the NS rotational energy, 
                         for L-X computed in the soft (2-10 keV) X-ray band. We compute the 
                         range of NS masses for which LX/Erot < 1. We discuss the observed 
                         hard X-ray emission in three sources of the group of nine 
                         potentially rotation-powered NSs. This additional hard X-ray 
                         component dominates over the soft one leading to LX/Erot > 1 in 
                         two of them. Conclusions. We show that 9 SGRs/AXPs can be 
                         rotation-powered NSs if we analyze their X-ray luminosity in the 
                         soft 2-10 keV band. Interestingly, four of them show radio 
                         emission and six have been associated with supernova remnants 
                         (including Swift J1834.9-0846 the first SGR observed with a 
                         surrounding wind nebula). These observations give additional 
                         support to our results of a natural explanation of these sources 
                         in terms of ordinary pulsars. Including the hard X-ray emission 
                         observed in three sources of the group of potential 
                         rotation-powered NSs, this number of sources with L-X/E-rot < 1 
                         becomes seven. It remains open to verification 1) the accuracy of 
                         the estimated distances and 2) the possible contribution of the 
                         associated supernova remnants to the hard X-ray emission.",
                  doi = "10.1051/0004-6361/201629521",
                  url = "http://dx.doi.org/10.1051/0004-6361/201629521",
                 issn = "0004-6361 and 1432-0746",
             language = "en",
        urlaccessdate = "01 dez. 2020"
}


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