Spectral Variability of a Soft-intermediate State QPO from MAXI J1820+070
Abstract
Black Hole X-ray binaries are known to exhibit variability in their light curves on timescales as short as milliseconds and as long as months. The short-timescale variability can be in the form of quasi-periodic oscillations (QPOs), which may be produced by general relativistic effects. In this work, we looked at low-frequency QPOs from an exciting recent black hole transient, MAXI J1820+070, which first went into outburst in 2018. This source was observed in a multi-wavelength campaign that included the NICER mission, a soft X-ray telescope attached to the International Space Station. In our analysis, we applied X-ray timing and spectral-timing techniques to help place constraints on the QPO emission mechanism in the extreme environment surrounding the black hole. Although the QPO amplitude was too low to carry out phase-resolved spectroscopy, our work indicates that weak QPOs such as this one may be present in the light curves of many sources.
- Publication:
-
Research Notes of the American Astronomical Society
- Pub Date:
- June 2020
- DOI:
- 10.3847/2515-5172/ab9f39
- Bibcode:
- 2020RNAAS...4...95D
- Keywords:
-
- High time resolution astrophysics;
- Black holes;
- Low-mass x-ray binary stars;
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- 162;
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