The accreting environment around the sg-HMXB IGR J18027-2016 through X-ray wind tomography.
Abstract
Supergiant High Mass X-ray Binaries (sg-HMXB) usually comprise of a neutron star accreting from the wind of an OB supergiant companion. As the neutron star moves through the dense stellar wind, it accretes material from its donor star and therefore emits X-rays. The wind will therefore be highly unstable revealing a very rich phenomenology. In other words, the presence of a neutron star, deeply embedded within the strong winds from its massive companion, strongly influences the wind flow, allowing to study of stellar wind properties in situ. For X-ray wind tomography, precise knowledge of the orbital phase is essential. In this regard, we utilize archival data for IGR J18027-2016 using XMM-Newton, NuStar, and swift satellites. The plethora of all these data can further constrain the orbit of the system and hence allow for an accurate wind tomography along its newly refined orbit. Spectral analysis shows a strong variability along the orbit, a signature of a dense accretion wake trailing the neutron star, revealing an absorbing column density reaching up to ∼1024 cm-2. To further shed light on the nature of the accretion flow around this system, we employ state-of-the-art hydrodynamical simulations to reproduce the observed variability of the absorbing column density. Comparison between the simulations and the observations can provide new estimates on the geometrical, dynamical, and wind parameters of this system. Recent developments on the accretion models in massive binaries, ranging from detailed descriptions of the wind acceleration to modeling of the structure of the flow of matter on a global (binary-wide) scale and on a very close to the neutron star are discussed.
- Publication:
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44th COSPAR Scientific Assembly. Held 16-24 July
- Pub Date:
- July 2022
- Bibcode:
- 2022cosp...44.2378M