NICER follow-up of the new black hole transient MAXI J1820+070
Abstract
On March 11, 2018, a new black hole transient, MAXI J1820+070 emerged from quiescence to become one of the brightest sources in the X-ray sky. In this talk, I will give an overview of the subsequent X-ray observations as it transitioned from hard coronal-dominated to soft-thermal dominated, and back again. I will put particular emphasis on NICER observations that revealed reverberation lags that shortened by an order of magnitude during the luminous hard state, during which the shape of the broad iron line remained constant. This suggests that the state transition is driven by a change in the vertical extent of the corona, rather than a reduction in the truncation radius of the accretion disc.
- Publication:
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AAS/High Energy Astrophysics Division
- Pub Date:
- March 2019
- Bibcode:
- 2019HEAD...1730401K