We present the results of a spectroscopic study of the Fe Kα emission of the persistent neutron-star atoll low-mass X-ray binary and type I X-ray burster GX 3+1 with the EPIC-PN on board XMM-Newton. The source shows a flux modulation over several years and we observed it during its fainter phase, which corresponds to an X-ray luminosity of LX ~ 1037 erg s-1. When fitted with a two-component model, the X-ray spectrum shows broad residuals at ~6-7 keV that can be ascribed to an iron Kα fluorescence line. In addition, lower energy features are observed at ~3.3 keV, ~3.9 keV and might originate from Ar XVIII and Ca XIX. The broad iron line feature is well fitted with a relativistically smeared profile. This result is robust against possible systematics caused by instrumental pile-up effects. Assuming that the line is produced by reflection from the inner accretion disk, we infer an inner disk radius of ~25Rg and a disk inclination of 35° < i < 44°.

Piraino, S., Santangelo, A., Kaaret, P., Mück, B., D'Aì, A., Di Salvo, T., et al. (2012). A relativistic iron emission line from the neutron star low-mass X-ray binary GX 3+1. ASTRONOMY & ASTROPHYSICS, 542(L 27) [10.1051/0004-6361/201219283].

A relativistic iron emission line from the neutron star low-mass X-ray binary GX 3+1

DI SALVO, Tiziana;IARIA, Rosario;
2012-01-01

Abstract

We present the results of a spectroscopic study of the Fe Kα emission of the persistent neutron-star atoll low-mass X-ray binary and type I X-ray burster GX 3+1 with the EPIC-PN on board XMM-Newton. The source shows a flux modulation over several years and we observed it during its fainter phase, which corresponds to an X-ray luminosity of LX ~ 1037 erg s-1. When fitted with a two-component model, the X-ray spectrum shows broad residuals at ~6-7 keV that can be ascribed to an iron Kα fluorescence line. In addition, lower energy features are observed at ~3.3 keV, ~3.9 keV and might originate from Ar XVIII and Ca XIX. The broad iron line feature is well fitted with a relativistically smeared profile. This result is robust against possible systematics caused by instrumental pile-up effects. Assuming that the line is produced by reflection from the inner accretion disk, we infer an inner disk radius of ~25Rg and a disk inclination of 35° < i < 44°.
Settore FIS/05 - Astronomia E Astrofisica
http://adsabs.harvard.edu/abs/2012A%26A...542L..27P
Piraino, S., Santangelo, A., Kaaret, P., Mück, B., D'Aì, A., Di Salvo, T., et al. (2012). A relativistic iron emission line from the neutron star low-mass X-ray binary GX 3+1. ASTRONOMY & ASTROPHYSICS, 542(L 27) [10.1051/0004-6361/201219283].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/64191
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