The XMM-newton and integral observations of the supergiant fast X-ray transient IGR J16328-4726

Journal Article · Sat Oct 01 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/829/2/125· OSTI ID:22868627

Fiocchi, M.; Bazzano, A.; Natalucci, L.; Ubertini, P.; Persi, P.; Piro, L. ^[1]; Sguera, V. ^[2]; Bird, A. J.; Boon, C. M. ^[3]

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1. INAF, Istituto di Astrofisica e Planetologia Spaziali, Via Fosso del Cavaliere 100, I-00133 Roma (Italy)
2. INAF, Istituto di Astrofisica Spaziale e Fisica Cosmica, Via Gobetti 101, I-40129 Bologna (Italy)
3. School of Physics and Astronomy, University of Southampton, University Road, Southampton, SO17 1BJ (United Kingdom)

The accretion mechanism producing the short flares observed from the Supergiant Fast X-ray Transients (SFXT) is still highly debated and forms a major part in our attempts to place these X-ray binaries in the wider context of the High Mass X-ray Binaries. We report on a 216 ks INTEGRAL observation of the SFXT IGR J16328-4726 (2014 August 24–27) simultaneous with two fixed-time observations with XMM-Newton (33 and 20 ks) performed around the putative periastron passage, in order to investigate the accretion regime and the wind properties during this orbital phase. During these observations, the source has shown luminosity variations, from ∼4×10{sup 34} to ∼10{sup 36} erg s{sup −1}, linked to spectral properties changes. The soft X-ray continuum is well modeled by a power law with a photon index varying from ∼1.2 up to ∼1.7 and with high values of the column density in the range of ∼2--4×10{sup 23} cm{sup −2}. We report on the presence of iron lines at ∼6.8–7.1 keV, suggesting that the X-ray flux is produced by the accretion of matter from the companion wind characterized by density and temperature inhomogeneities.

• OSTI ID: 22868627
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 829; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
COSMIC X-RAY SOURCES
DENSITY
IRON
LUMINOSITY
MASS
PHOTONS
SOFT X RADIATION
SUPERGIANT STARS
TRANSIENTS