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Black hole spin-orbit misalignment in the x-ray binary MAXI J1820+070.
Juri Poutanen1,2,3, Alexandra Veledina1,2,3, Andrei V Berdyugin1
1Department of Physics and Astronomy, FI-20014 University of Turku, Finland.
Science (New York, N.Y.)
|February 24, 2022
Summary
Black hole spin-orbit misalignment in X-ray binaries can exceed 40°. This significant misalignment, observed in MAXI J1820+070, may bias black hole mass and spin measurements from X-ray data.
Area of Science:
- Astrophysics
- X-ray Astronomy
- Black Hole Physics
Background:
- Observational signatures of black holes in X-ray binaries are influenced by mass, spin, accretion rate, and spin-orbit misalignment.
- Understanding these parameters is crucial for accurate black hole characterization.
Purpose of the Study:
- To constrain the spin-orbit misalignment angle in the black hole X-ray binary MAXI J1820+070.
- To investigate the implications of such misalignments on black hole parameter measurements.
Main Methods:
- Optical polarimetric observations were used to determine the binary orbital position angle.
- Combined with existing data on jet orientation (tracing black hole spin) and orbital inclination.
Main Results:
- A lower limit of 40° was determined for the spin-orbit misalignment angle in MAXI J1820+070.
- This significant misalignment suggests origins in binary evolution or black hole formation.
Conclusions:
- Large spin-orbit misalignments are present in black hole X-ray binaries.
- Such misalignments can introduce biases in black hole mass and spin measurements derived from X-ray observations.
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