SIMBAD references

2021MNRAS.508.3569K - Mon. Not. R. Astron. Soc., 508, 3569-3588 (2021/December-2)

Ionized emission and absorption in a large sample of ultraluminous X-ray sources.

KOSEC P., PINTO C., REYNOLDS C.S., GUAINAZZI M., KARA E., WALTON D.J., FABIAN A.C., PARKER M.L. and VALTCHANOV I.

Abstract (from CDS):

Most ultraluminous X-ray sources (ULXs) are thought to be powered by super-Eddington accretion on to stellar-mass compact objects. Accretors in this extreme regime are naturally expected to ionize copious amounts of plasma in their vicinity and launch powerful radiation-driven outflows from their discs. High spectral resolution X-ray observations [with reflection grating spectrometer (RGS) gratings onboard XMM-Newton] of a few ULXs with the best data sets indeed found complex line spectra and confirmed such extreme (0.1-0.3c) winds. However, a search for plasma signatures in a large ULX sample with a rigorous technique has never been performed, thereby preventing us from understanding their statistical properties such as the rate of occurrence, to constrain the outflow geometry, and its duty cycle. We developed a fast method for automated line detection in X-ray spectra and applied it to the full RGS ULX archive, rigorously quantifying the statistical significance of any candidate lines. Collecting the 135 most significant features detected in 89 observations of 19 objects, we created the first catalogue of spectral lines detected in soft X-ray ULX spectra. We found that the detected emission lines are concentrated around known rest-frame elemental transitions and thus originate from low-velocity material. The absorption lines instead avoid these transitions, suggesting they were imprinted by blueshifted outflows. Such winds therefore appear common among the ULX population. Additionally, we found that spectrally hard ULXs show fewer line detections than soft ULXs, indicating some difference in their accretion geometry and orientation, possibly causing overionization of plasma by the harder spectral energy distributions of harder ULXs.

Abstract Copyright: © 2021 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society

Journal keyword(s): accretion, accretion discs - X-rays: binaries

Status at CDS : Large table(s) will be appraised for possible ingestion in VizieR.

Simbad objects: 22

goto Full paper

goto View the references in ADS

To bookmark this query, right click on this link: simbad:2021MNRAS.508.3569K and select 'bookmark this link' or equivalent in the popup menu


2022.08.14-15:08:20

© Université de Strasbourg/CNRS

    • Contact