Astrophysicist simulating and imaging Black Holes with the Event Horizon Telescope. Black holes, accretion disks & jets, MHD simulations, computational imaging, and other topics.

achael@princeton.edu

465 Jadwin Hall
Princeton University
Princeton, NJ 08540

You can find my papers in this ADS library or on ArXiv.

Dissertation

Here is a link to my thesis, “Simulating and Imaging Supermassive Black Hole Accretion Flows”.

EHT Collaboration Papers

  • The Event Horizon Telescope Collaboration et al.
    “First Sagittarius A* Event Horizon Telescope Results. I–VIII”. ApJL 964, 2022,2023.
    ApJL (open access)

  • The Event Horizon Telescope Collaboration et al.
    “First M87 Event Horizon Telescope Results. I–IX”. ApJL 875, 2019,2021.
    ApJL (open access)

First Author and Primary Collaboration Papers

  • A Chael.
    “Hybrid GRMHD and force-free simulations of black hole accretion”. MNRAS 532, 2024.
    MNRAS | arXiv

  • A Chael, A Lupsasca, GN Wong, E Quataert.
    “Black hole polarimetry I: a signature of electromagnetic energy extraction”. ApJ 958, 2023.
    ApJ | arXiv

  • The Event Horizon Telescope Collaboration et al. (paper coordinator).
    “First Event Horizon Telescope Results IX: detection of near-horizon circular polarization”. ApJL 957, 2023.
    ApJL

  • A Chael, S Issaoun, D Pesce, M Johnson, A Ricarte, C Fromm, Y Mizuno.
    “Multifrequency imaging for the next-generation Event Horizon Telescope”. ApJ 945, 2023. ApJ | arXiv

  • The Event Horizon Telescope Collaboration et al. (paper writing team).
    “First Sagittarius A* Event Horizon Telescope Results III: imaging of the Galactic Center supermassive black hole”. ApJL 930, 2022.
    ApJL

  • A Chael, M Johnson, A Lupsasca.
    “Observing the inner shadow of a black hole: a direct view of the event horizon”. ApJ 918, 2021.
    MNRAS | arXiv

  • The Event Horizon Telescope Collaboration et al. (paper coordinator).
    “First Event Horizon Telescope Results VIII: magnetic field structure near the event horizon”. ApJL 910, 2021.
    ApJL

  • The Event Horizon Telescope Collaboration et al. (paper writing team).
    “First Event Horizon Telescope Results VII: polarization of the ring”. ApJL 910, 2021.
    ApJL

  • A Chael, R Narayan, M Johnson.
    “Two-temperature, Magnetically Arrested Disc simulations of the supermassive black hole in M87”. MNRAS 486, 2019.
    MNRAS | arXiv

  • The Event Horizon Telescope Collaboration et al. (paper writing team).
    “First Event Horizon Telescope Results IV: imaging the central supermassive black hole”. ApJL 875, 2019.
    ApJL

  • A Chael, M Rowan, R Narayan, MD Johnson, L Sironi.
    “The role of electron heating physics in images and variability of the Galactic Center black hole Sagittarius A*’’. MNRAS 478, 2018.
    MNRAS | arXiv

  • A Chael, MD Johnson, KL Bouman, L Blackburn, K Akiyama, R Narayan.
    “Interferometric imaging directly with closure phases and closure amplitudes”. ApJ 857, 2018.
    ApJ | arXiv

  • A Chael, R Narayan, A Sadowski.
    “Evolving non-thermal electrons in simulations of black hole accretion”. MNRAS 470, 2017.
    MNRAS | arXiv

  • A Chael, MD Johnson, R Narayan, SS Doeleman, J Wardle, KL Bouman.
    “High-resolution linear polarimetric imaging for the Event Horizon Telescope”. ApJ 829, 2016.
    ApJ | arXiv

Other Selected Papers

  • T Desire, A Chael, A Cardenas-Avendano. “Multi-frequency models of black hole photon rings from low-luminosity accretion disks.” ApJ, submitted.
    ArXiv

  • Z Gelles, A Chael, E Quataert. “Signatures of black hole spin and plasma acceleration in jet polarimetry.” ApJ, submitted.
    ArXiv

  • A Raymond et al. “First Very Long Baseline Interferometry detections at 870 $\mu$m.” AJ 168, 3, 2024.
    AJ | ArXiv

  • MD Johnson et al.
    “The Black Hole Explorer: motivation and vision.” Proc. SPIE Astron. 2024.
    SPIE | ArXiv

  • A Levis, P Srinivasan, A Chael, R Ng, KL Bouman.
    “Orbital polarimetric tomography of a flare near the Sagittarius A* supermassive black hole.” Nat. Astron. 8, 2024.
    Nature Astronomy | ArXiv

  • The Event Horizon Telescope Collaboration et al. “The persistent shadow of the supermassive black hole of M 87. I. Observations, calibration, imaging, and analysis.” A&A 681, A79, 2024.
    A&A

  • A Fuentes et al.
    “Filamentary structures as the origin of blazar jet radio variability”. Nat. Astron. 7, 2024.
    Nature Astronomy | ArXiv

  • F Roelofs, MD Johnson, A Chael et al. “Polarized geometric modeling for mm-VLBI observations of black holes.” ApJL 957, L21, 2023.
    ApJL | ArXiv

  • DCM Palumbo, GN Wong, A Chael, MD Johnson.
    “Demonstrating photon ring existence with single-baseline polarimetry”. ApJL 952, 2023.
    ApJL | ArXiv

  • R Qiu, A Ricarte, R narayan, GN Wong, A Chael, DCM Palumbo. “Using machine learning to link black hole accretion flows with spatially resolved polarimetric observables.” MNRAS 520, p.4867-4888, 2023.
    MNRAS | ArXiv

  • MD Johnson et al.
    “Key science goals for the next-generation Event Horizon Telescope”. Galaxies 11, 2023.
    Galaxies | ArXiv

  • K Chatterjee, A Chael et al. “Accretion Flow Morphology in Numerical Simulations of Black Holes from the ngEHT Model Library: The Impact of Radiation Physics.” Galaxies 11, 2, 2023.
    Galaxies | ArXiv

  • S Issaoun et al.
    “Enabling transformational ngEHT science via the inclusion of 86 GHz capabilities”. Galaxies 11, 2023.
    Galaxies | ArXiv

  • P Tiede, AE Broderick, DCM Palumbo, A Chael. “Measuring the ellipticity of M87* images.” ApJ 940, 2, 2022.
    ApJ | ArXiv

  • H Okino et al. “Collimation of the relativistic jet in the quasar 3C 273.” ApJ 940, 1, 2022.
    ApJ | ArXiv

  • DCM Palumbo et al. “Bayesian accretion modeling: axisymmetric equatorial emission in the Kerr spacetime.” ApJ 939, 2, 2022. ApJ | ArXiv

  • S Issaoun et al.
    “Resolving the inner parsec of the blazar J1924-2914 with the Event Horizon Telescope.” ApJ 934, 2022.
    ApJ | ArXiv

  • J Farah, P Galison, K Akiyama, KL Bouman, GC Bower, A Chael, et al. “Selective dynamical imaging of interferometric data.” ApJL 930, L18, 2022. ApJL | ArXiv

  • A Levis, P Srinivasan, A Chael, R Ng, KL Bouman.
    “Gravitationally lensed black hole emission tomography.” IEEE Proceedings of the CVPR, 2022.
    CVF | ArXiv

  • R Narayan, A Chael, K Chatterjee, A Ricarte, B Curd.
    “Jets in magnetically arrested accretion flows: geometry, power and black hole spindown”. MNRAS 511, p.3795-3813, 2022. MNRAS | ArXiv

  • M Janssen et al.
    “Event Horizon Telescope observations of the jet launching and collimation in Centaurus A”. Nature Astronomy 2021.
    Nature Astronomy | ArXiv

  • S Issaoun et al. “Persistant non-Gaussian structure in the image of Sagittarius A* at 86 GHz.” ApJ 915, 2, 2021. ApJ | ArXiv

  • R Narayan et al. “The polarized image of a synchrotron-emtting ring of gas orbiting a black hole.” ApJ 912, 35, 2021. ApJ | ArXiv

  • M Wielgus et al.
    “Monitoring the morphology of M87* in 2009-2017 with the Event Horizon Telescope”. ApJ 901, 2020.
    ApJ | ArXiv

  • L Blackburn et al. “Closure statistics in interferometric data.” ApJ 894, 31, 2020. ApJ | ArXiv

  • J-Y Kim et al. “Event Horizon Telescope Imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution” A&A 640, A69, 2020. A&A

  • M Johnson et al.
    “Universal interferometric signatures of a black hole’s photon ring”. Science Advances 6, 2020.
    Science Advances | ArXiv

  • L Blackburn et al. “Studying black holes on horizon scales with VLBI arrays.” Astro2020 White Paper ArXiv

  • S Issaoun, MD Johnson, L Blackburn, M Moscibrodzka, A Chael, H Falcke. “VLBI imaging of black holes via second moment regularization”. A&A 629, 2019.
    A&A | ArXiv

  • S Issaoun et al. “The size, shape, and scattering of Sagittarius A* at 86 GHz: first VLBI with ALMA”. ApJ 871, 2019.
    ApJ | ArXiv

  • W Lu, C Dvorkin, A Chael. “Probing sub-GeV dark matter-baryon scattering with cosmological observables”. Phys. Rev. D 97, 2018.
    Phys. Rev. D | ArXiv

  • KL Bouman, MD Johnson, A Dalca, A Chael, F Roelofs, SS Doeleman, W Freeman. “Reconstructing video from interferometric measurements of time-varying sources”. IEEE Transactions on Computational Imaging, 2018.
    IEEE | ArXiv

  • MD Johnson, KL Bouman, L Blackburn, A Chael, J Rosen, H Shiokawa, F Roelofs, K Akiyama, V Fish, SS Doeleman. “Dynamical imaging with interferometry”. ApJ 850, 2018.
    ApJ | ArXiv

  • A Sadowski, M Wielgus, R Narayan, D Abarca, J McKinney, A Chael. “Radiative, two-temperature simulations of low-luminosity black hole accretion flows in general relativity”. MNRAS 466, 2018.
    MNRAS | ArXiv

  • K Akiyama, K Kuramochi, S Ikeda, V Fish, F Tazaki, M Honma, SS Doeleman, A Broderick, J Dexter, M Moscibrodzka, KL Bouman, A Chael, A Zaizen. “Imaging the Schwarzschild-radius-scale structure of M87 with the Event Horizon Telescope using sparse modeling”. ApJ 838, 2017.
    ApJ | ArXiv

  • G Ortiz-Leon et al.
    “The intrinsic shape of Sagittarius A* at 3.5-mm wavelength”. ApJ 824, 2016.
    ApJ | ArXiv

  • V Fish et al. “Persistent asymmetric structure of Sagittarius A* on event horizon scales”. ApJ 820, 2016.
    ApJ | ArXiv

  • MD Johnson et al.
    “Resolved magnetic field structure and variability near the event horizon of Sagittarius A*”. Science 350, 2015.
    Science | ArXiv

  • MD Johnson, A Loeb, H Shiokawa, A Chael, SS Doeleman. “Measuring the direction and angular velocity of a black hole accretion disk via lagged interferometric covariance”. ApJ 813, 2015.
    ApJ | ArXiv

  • P Verbiest, J Weisberg, A Chael, K Lee, D Lorimer. “On pulsar distance measures and their uncertainties”.
    ApJ 775, 2012.
    ApJ | ArXiv