We report on the spectral and timing properties of the accreting millisecond X-ray pulsar IGR J00291+5934 observed by XMM-Newton and NuSTAR during its 2015 outburst. The source is in a hard state dominated at high energies by a Comptonization of soft photons (~0.9 keV) by an electron population with kTe ~30 keV, and at lower energies by a blackbody component with kT ~ 0.5 keV. A moderately broad, neutral Fe emission line and four narrow absorption lines are also found. By investigating the pulse phase evolution, we derived the best-fitting orbital solution for the 2015 outburst. Comparing the updated ephemeris with those of the previous outbursts, we set a 3σ confidence level interval -6.6 × 10-13 s s-1 < P˙ orb < 6.5 × 10-13 s s-1 on the orbital period derivative. Moreover, we investigated the pulse profile dependence on energy finding a peculiar behaviour of the pulse fractional amplitude and lags as a function of energy.We performed a phase-resolved spectroscopy showing that the blackbody component tracks remarkably well the pulse profile, indicating that this component resides at the neutron star surface (hotspot).

Sanna, A., Pintore, F., Bozzo, E., Ferrigno, C., Papitto, A., Riggio, A., et al. (2017). Spectral and timing properties of IGR J00291+5934 during its 2015 outburst. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 466(3), 2910-2917 [10.1093/mnras/stw3332].

Spectral and timing properties of IGR J00291+5934 during its 2015 outburst

DI SALVO, Tiziana;IARIA, Rosario;
2017-01-01

Abstract

We report on the spectral and timing properties of the accreting millisecond X-ray pulsar IGR J00291+5934 observed by XMM-Newton and NuSTAR during its 2015 outburst. The source is in a hard state dominated at high energies by a Comptonization of soft photons (~0.9 keV) by an electron population with kTe ~30 keV, and at lower energies by a blackbody component with kT ~ 0.5 keV. A moderately broad, neutral Fe emission line and four narrow absorption lines are also found. By investigating the pulse phase evolution, we derived the best-fitting orbital solution for the 2015 outburst. Comparing the updated ephemeris with those of the previous outbursts, we set a 3σ confidence level interval -6.6 × 10-13 s s-1 < P˙ orb < 6.5 × 10-13 s s-1 on the orbital period derivative. Moreover, we investigated the pulse profile dependence on energy finding a peculiar behaviour of the pulse fractional amplitude and lags as a function of energy.We performed a phase-resolved spectroscopy showing that the blackbody component tracks remarkably well the pulse profile, indicating that this component resides at the neutron star surface (hotspot).
2017
Sanna, A., Pintore, F., Bozzo, E., Ferrigno, C., Papitto, A., Riggio, A., et al. (2017). Spectral and timing properties of IGR J00291+5934 during its 2015 outburst. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 466(3), 2910-2917 [10.1093/mnras/stw3332].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10447/228375
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