Is the lack of pulsations in low mass X-Ray binaries due to comptonizing coronae?
Göğüş, Ersin and Alpar, M. Ali and Gilfanov, Marat (2007) Is the lack of pulsations in low mass X-Ray binaries due to comptonizing coronae? The Astrophysical journal, 659 (1). pp. 580-584. ISSN 0004-637X
Official URL: http://dx.doi.org/10.1086/512028
The spin periods of the neutron stars in most Low Mass X-ray Binary (LMXB) systems still remain undetected. One of the models to explain the absence of coherent pulsations has been the suppression of the beamed signal by Compton scattering of X-ray photons by electrons in a surrounding corona. We point out that simultaneously with wiping out the pulsation signal, such a corona will upscatter (pulsating or not) X-ray emission originating at and/or near the surface of the neutron star leading to appearance of a hard tail of Comptonized radiation in the source spectrum. We analyze the hard X-ray spectra of a selected set of LMXBs and demonstrate that the optical depth of the corona is not likely to be large enough to cause the pulsations to disappear.
Repository Staff Only: item control page