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Evidence for Fe Kα line and soft X-ray lag in NGC 7456 ultraluminous X-ray source-1.
- Source :
- Monthly Notices of the Royal Astronomical Society: Letters; Jul2021, Vol. 505 Issue 1, pL106-L111, 6p
- Publication Year :
- 2021
-
Abstract
- We report the first detection of an Fe K<subscript>α</subscript> line and soft X-ray lag in the ultraluminous X-ray (ULX) source NGC 7456 ULX-1. The XMM–Newton spectra show the presence of the 6.4 keV Fe line at 2.6σ confidence and an upper limit on the FWHM of 32900 km s<superscript>−1</superscript>. Assuming that the line arises by reflection from a Keplerian disk, it must originate beyond 85 r <subscript>g</subscript> from the compact object. As a result of Fourier timing analysis, we found that the soft X-ray photons lag behind the hard X-ray photons with a ∼1300 s delay. The covariance spectra indicate that the hard spectral component is responsible for the correlated variability and the soft X-ray lag. This is the second ULX in which an Fe K<subscript>α</subscript> line is found, the fifth with a soft X-ray lag, and the first with both features detected. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 17453925
- Volume :
- 505
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Monthly Notices of the Royal Astronomical Society: Letters
- Publication Type :
- Academic Journal
- Accession number :
- 151270342
- Full Text :
- https://doi.org/10.1093/mnrasl/slab061