Accretion Geometry in the Hard State of the Black-Hole X-Ray Binary MAXI J1820+070

Abstract

We study X-ray spectra from the outburst rise of the accreting black-hole binary MAXI J1820+070. We find that models having the disk inclinations within those of either the binary or the jet imply significant changes of the accretion disk inner radius during the luminous part of the hard spectral state, with that radius changing from $>$100 to $\sim$10 gravitational radii. The main trend is a decrease with the decreasing spectral hardness. Our analysis requires the accretion flow to be structured, with at least two components with different spectral slopes. The harder component dominates the bolometric luminosity and produces strong, narrow, X-ray reflection features. The softer component is responsible for the underlying broader reflection features. The data are compatible with the harder component having a large scale height, located downstream the disk truncation radius, and reflecting mostly from remote parts of the disk. The softer component forms a corona above the disk up to some transition radius. Our findings can explain the changes of the characteristic variability time scales, found in other works, as being driven by the changes of the disk characteristic radii.

ApJL, 909, L9 (2021)

References in corpus (11)

• Modelling the behaviour of accretion flows in X-ray binaries
• The corona contracts in a black-hole transient
• A radio parallax to the black hole X-ray binary MAXI J1820+070
• Discovery of oscillations above 200 keV in a black hole X-ray binary with Insight-HXMT
• The binary mass ratio in the black hole transient MAXI J1820+070
• X-ray and Optical Monitoring of State Transitions in MAXI J1820+070
• X-ray dips and a complex UV/X-ray cross-correlation function in the black hole candidate MAXI J1820+070
• Black hole magnetosphere with small scale flux tubes--II. Stability and dynamics
• The evolution of the broadband temporal features observed in the black-hole transient MAXI J1820+070 with Insight-HXMT
• A spectral study of the black hole X-ray binary MAXI J1820+070 with AstroSat and NuSTAR
• Illumination of the accretion disk in black hole binaries: An extended jet as the primary source of hard X-rays

Cited by in corpus (18)

• Disk, Corona, Jet Connection in the Intermediate State of MAXI J1820+070 Revealed by NICER Spectral-Timing Analysis
• The NICER "Reverberation Machine": A Systematic Study of Time Lags in Black Hole X-Ray Binaries
• Phase-resolved spectroscopy of a quasi-periodic oscillation in the black hole X-ray binary GRS 1915+105 with NICER and NuSTAR
• A variable corona during the transition from type-C to type-B quasi-periodic oscillations in the black hole X-ray binary MAXI J1820+070
• Physical origin of the nonphysical spin evolution of MAXI J1820+070
• A timing-based estimate of the spin of the black hole in MAXI J1820+070
• A NICER look at the jet-like corona of MAXI J1535-571 through type-B quasi-periodic oscillations
• The Evolution of Rapid Optical/X-ray Timing Correlations in the Initial Hard State of MAXI J1820+070
• Accretion Scenario of MAXI J1820+070 during 2018 Outbursts with Multi-mission Observations
• The Donor of the Black-Hole X-Ray Binary MAXI J1820+070
• Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
• A possible overall scenario for the outburst evolution of MAXI J1820+070 revealed by Insight-HXMT
• X-ray spectral correlations in a sample of Low-mass black hole X-ray binaries in the hard state
• The long-stable hard state of XTE J1752-223 and the disk truncation dilemma
• Investigating the consistency of the shape and flux of X-ray reflection spectra in the hard state with an accretion disk reaching close to the black hole
• X-ray time lag evaluation of MAXI J1820+070 with a differential cross-correlation analysis
• The jet emitting disk standard accretion disk model applied to the active galactic nuclei ultra violet Xray correlation
• Evolution of X-ray and optical rapid variability during the low/hard state in the 2018 outburst of MAXI J1820+070 = ASASSN-18ey