Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT

We constrain the spin of the black hole candidate MAXI J1727-203 using Insight-HXMT data. Due to limited Insight-HXMT observations covering only part of the outburst, NICER data were used to analyze the full outburst’s state transitions; we identified two of three HXMT observations in the high soft...

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Main Authors: Haifan Zhu, Wei Wang
Format: Article
Language:English
Published: IOP Publishing 2025-01-01
Series:The Astrophysical Journal
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Online Access:https://doi.org/10.3847/1538-4357/adae8b
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author Haifan Zhu
Wei Wang
author_facet Haifan Zhu
Wei Wang
author_sort Haifan Zhu
collection DOAJ
description We constrain the spin of the black hole candidate MAXI J1727-203 using Insight-HXMT data. Due to limited Insight-HXMT observations covering only part of the outburst, NICER data were used to analyze the full outburst’s state transitions; we identified two of three HXMT observations in the high soft state and applied the continuum-fitting method to measure the spin. Based on previous estimates and continuum spectral fittings, we explored the parameter space and found that the best-fitting values were ( D , i , M ) ≈ (6 kpc, 30°, 12 M _⊙ ). We also tested the variation of these parameters using Monte Carlo simulations, sampling over 3000 sets within the parameter ranges 5.9 kpc <  D  < 7 kpc, 24° <  i  < 35°, and 10 M _⊙ < M < 14 M _⊙ , yielding a spin measurement of $a=0.3{4}_{-0.19}^{+0.15}$ (1 σ ). In addition, we analyzed NuSTAR data in the low hard state and found a good fit with the tbabs∗(diskbb+powerlaw) model, with no significant iron line features observed in the residuals; therefore, the previous reflection model results suggesting an extremely high spin overestimates the black hole spin.
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spelling doaj-art-bc28a3108d0d4ea29fda1f6f9606dc352025-08-20T02:43:49ZengIOP PublishingThe Astrophysical Journal1538-43572025-01-01980223710.3847/1538-4357/adae8bEstimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMTHaifan Zhu0https://orcid.org/0000-0002-4858-3001Wei Wang1https://orcid.org/0000-0003-3901-8403Department of Astronomy, School of Physics and Technology, Wuhan University , Wuhan 430072, People’s Republic of China ; wangwei2017@whu.edu.cnDepartment of Astronomy, School of Physics and Technology, Wuhan University , Wuhan 430072, People’s Republic of China ; wangwei2017@whu.edu.cnWe constrain the spin of the black hole candidate MAXI J1727-203 using Insight-HXMT data. Due to limited Insight-HXMT observations covering only part of the outburst, NICER data were used to analyze the full outburst’s state transitions; we identified two of three HXMT observations in the high soft state and applied the continuum-fitting method to measure the spin. Based on previous estimates and continuum spectral fittings, we explored the parameter space and found that the best-fitting values were ( D , i , M ) ≈ (6 kpc, 30°, 12 M _⊙ ). We also tested the variation of these parameters using Monte Carlo simulations, sampling over 3000 sets within the parameter ranges 5.9 kpc <  D  < 7 kpc, 24° <  i  < 35°, and 10 M _⊙ < M < 14 M _⊙ , yielding a spin measurement of $a=0.3{4}_{-0.19}^{+0.15}$ (1 σ ). In addition, we analyzed NuSTAR data in the low hard state and found a good fit with the tbabs∗(diskbb+powerlaw) model, with no significant iron line features observed in the residuals; therefore, the previous reflection model results suggesting an extremely high spin overestimates the black hole spin.https://doi.org/10.3847/1538-4357/adae8bBlack hole physicsStellar accretion disksKerr black holesX-ray binary starsHigh energy astrophysics
spellingShingle Haifan Zhu
Wei Wang
Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT
The Astrophysical Journal
Black hole physics
Stellar accretion disks
Kerr black holes
X-ray binary stars
High energy astrophysics
title Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT
title_full Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT
title_fullStr Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT
title_full_unstemmed Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT
title_short Estimating the Black Hole Spin for the X-Ray Binary MAXI J1727-203 Based on Insight-HXMT
title_sort estimating the black hole spin for the x ray binary maxi j1727 203 based on insight hxmt
topic Black hole physics
Stellar accretion disks
Kerr black holes
X-ray binary stars
High energy astrophysics
url https://doi.org/10.3847/1538-4357/adae8b
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