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Probing the Physical Properties of the Corona in Accreting Black Holes

Kamraj, Nikita and Fabian, Andrew and Lohfink, Anne and Baloković, Mislav and Ricci, Claudio and Madsen, Kristin (2019) Probing the Physical Properties of the Corona in Accreting Black Holes. Astro2020 Science White Paper, . (Unpublished)

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The corona is a key component of most luminous accreting black holes, carrying 5 - 30 % of the power and in non-jetted Active Galactic Nuclei (AGN), creating all the X-ray emission above ≃1−2 keV. Its emission illuminates the inner accretion disc, creating the atomic line-rich reflection spectrum used to diagnose and map the accretion flow and measure black hole spin. The corona is likely powered magnetically by the strong differential rotation of the accretion disc and it may be intimately related to relativistic jets. Recent work shows that many black hole coronae may be dominated by electron-positron pairs produced by photon-photon collisions in the compact coronal environment. Despite the corona being an integral component of AGN and black hole binary systems, much is still unknown about the nature of the corona, such as its geometry, location, and the physical mechanisms powering the emission. In this white paper we explore our current understanding of coronal properties, such as its temperature, obtained from measurements with existing hard X-ray telescopes such as NuSTAR, and discuss important questions to be addressed in the coming decade surrounding the nature of the corona. Hard X-ray observations will continue to dispel the mystery of coronae and open up this part of the quasar engine to full understanding.

Item Type:Report or Paper (White Paper)
Related URLs:
URLURL TypeDescription Paper
Kamraj, Nikita0000-0002-3233-2451
Fabian, Andrew0000-0002-9378-4072
Baloković, Mislav0000-0003-0476-6647
Ricci, Claudio0000-0001-5231-2645
Madsen, Kristin0000-0003-1252-4891
Group:Space Radiation Laboratory
Subject Keywords:Formation and Evolution of Compact Objects, Galaxy Evolution
Series Name:Astro2020 Science White Paper
Record Number:CaltechAUTHORS:20190917-134419227
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:98682
Deposited By: Tony Diaz
Deposited On:17 Sep 2019 21:43
Last Modified:03 Oct 2019 21:43

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