Spectral analysis of IGR J01572-7259 during its 2016 outburst

Abstract

We report on the results of the $XMM-Newton$ observation of IGR J01572-7259 during its most recent outburst in 2016 May, the first since 2008. The source reached a flux $f\sim 10^{-10}$ erg cm${}^{-2}$ s${}^{-1}$, which allowed us to perform a detailed analysis of its timing and spectral properties. We obtained a pulse period $P_{\mathrm{spin}}$ = 11.58208(2) s. The pulse profile is double peaked and strongly energy dependent, as the second peak is prominent only at low energies and the pulsed fraction increases with energy. The main spectral component is a power-law model, but at low energies we also detected a soft thermal component, which can be described with either a blackbody or a hot plasma model. Both the EPIC and RGS spectra show several emission lines, which can be identified with the transition lines of ionized N, O, Ne, and Fe and cannot be described with a thermal emission model. The phase-resolved spectral analysis showed that the flux of both the soft excess and the emission lines vary with the pulse phase: the soft excess disappears in the first pulse and becomes significant only in the second, where also the Fe line is stronger. This variability is difficult to explain with emission from a hot plasma, while the reprocessing of the primary X-ray emission at the inner edge of the accretion disk provides a realiable scenario. On the other hand, the narrow emission lines can be due to the presence of photoionized matter around the accreting source.

arXiv comment10 pages, 7 figures, 5 tables. Accepted for publication by Monthly Notices of the Royal Astronomical Society

References in corpus (18)

• On the Absorption of X-rays in the Interstellar Medium
• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
• The USNO-B Catalog
• Atomic Data for Astrophysics. II. New Analytic Fits for Photoionization Cross Sections of Atoms and Ions
• Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs
• An eclipsing binary distance to the Large Magellanic Cloud accurate to 2 per cent
• The Araucaria Project. The distance to the Small Magellanic Cloud from late-type eclipsing binaries
• Origin of the Soft Excess in X-ray Pulsars
• The Carnegie Hubble Program: The Distance and Structure of the SMC as Revealed by Mid-infrared Observations of Cepheids
• XMM-Newton observations reveal the disappearance of the wind in 4U 1630-47
• The Discovery of an Outburst and Pulsed X-ray Flux from SMC X-2 from RXTE Observations
• Broad-Band X-Ray Study of a Transient Pulsar RX J0059.2-7138
• Spectral analysis of SMC X-2 during its 2015 outburst
• ASCA Identification of SMC X-2 with the 2.37-s Pulsar Discovered by RXTE
• The Magellanic Bridge: evidence for a population of X-ray binaries
• Swift discovery of the orbital period of the HMXB IGR J015712-7259 in the Small Magellanic Cloud
• Spectral properties of the soft excess pulsar RX J0059.2-7138 during its 2013 outburst

Cited by in corpus (2)

• Spectral analysis of SXP59.0 during its 2017 outburst and properties of the soft excess in X-ray binary pulsars
• Discovery of a magnetar candidate X-ray pulsar in the Large Magellanic Cloud