XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658 Export

@article{citeulike:3755395, abstract = {We report on a 63-ks long XMM-Newton observation of the accreting millisecond pulsar SAX J1808.4-3658 during the latest X-ray outburst which started on September 21st 2008. The pn spectrum shows a highly significant emission line in the energy band where the iron K-alpha line is expected, and which we identify as emission from neutral (or mildly ionized) iron. The line profile appears to be quite broad (more than 1 keV FWHM) and asymmetric; the most probable explanation for this profile is Doppler and relativistic broadening from the inner accretion disc. From a fit with a diskline profile we find an inner radius of the disc of 8.7^(+3.7)\_(-2.7) R\_g, corresponding to 18.0^(+7.6)\_(-5.6) km for a 1.4 Msun neutron star. The disc therefore appears truncated inside the corotation radius (31 km for SAX J1808.4-3658) in agreement with the fact that the source was still showing pulsations during the XMM-Newton observation.}, archivePrefix = {arXiv}, author = {Papitto, A. and Di Salvo, T. and D\&\#x27;a\&\#xec;, A. and Iaria, R. and Burderi, L. and Riggio, A. and Menna, M. T. and Robba, N. R.}, citeulike-article-id = {3755395}, citeulike-linkout-0 = {http://arxiv.org/abs/0812.1149}, citeulike-linkout-1 = {http://arxiv.org/pdf/0812.1149}, day = {5}, eprint = {0812.1149}, keywords = {accretion, binaries, disks, individual, j180843658, lineprofiles, pulsars, relativity, sax, xrays}, month = {Dec}, posted-at = {2008-12-08 10:19:39}, priority = {5}, title = {XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658}, url = {http://arxiv.org/abs/0812.1149}, year = {2008} }

TY - JOUR ID - citeulike:3755395 L3 - citeulike-article-id:3755395 N2 - We report on a 63-ks long XMM-Newton observation of the accreting millisecond pulsar SAX J1808.4-3658 during the latest X-ray outburst which started on September 21st 2008. The pn spectrum shows a highly significant emission line in the energy band where the iron K-alpha line is expected, and which we identify as emission from neutral (or mildly ionized) iron. The line profile appears to be quite broad (more than 1 keV FWHM) and asymmetric; the most probable explanation for this profile is Doppler and relativistic broadening from the inner accretion disc. From a fit with a diskline profile we find an inner radius of the disc of 8.7^(+3.7)_(-2.7) R_g, corresponding to 18.0^(+7.6)_(-5.6) km for a 1.4 Msun neutron star. The disc therefore appears truncated inside the corotation radius (31 km for SAX J1808.4-3658) in agreement with the fact that the source was still showing pulsations during the XMM-Newton observation. TI - XMM-Newton detects a relativistically broadened iron line in the spectrum of the ms X-ray pulsar SAX J1808.4-3658 KW - accretion KW - binaries KW - disks KW - individual KW - j180843658 KW - lineprofiles KW - pulsars KW - relativity KW - sax KW - xrays AU - Papitto, A AU - Di Salvo, T AU - D'aì, A AU - Iaria, R AU - Burderi, L AU - Riggio, A AU - Menna, MT AU - Robba, NR PY - 2008/Dec/05/ UR - http://arxiv.org/abs/0812.1149 ER -