Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: How well can we measure supermassive black hole spin?   Being one of only two fundamental properties black holes possess, the spin of
supermassive black holes (SMBHs) is of great interest for understanding
accretion processes and galaxy evolution. However, in these early days of spin
measurements, consistency and reproducibility of spin constraints have been a
challenge. Here we focus on X-ray spectral modelling of active galactic nuclei
(AGN), examining how well we can truly return known reflection parameters such
as spin under standard conditions. We have created and fit over 4000 simulated
Seyfert 1 spectra each with 375$\pm$1k counts. We assess the fits with
reflection fraction of $R$ = 1 as well as reflection-dominated AGN with $R$ =
5. We also examine the consequence of permitting fits to search for retrograde
spin. In general, we discover that most parameters are over-estimated when
spectroscopy is restricted to the 2.5 - 10.0 keV regime and that models are
insensitive to inner emissivity index and ionization. When the bandpass is
extended out to 70keV, parameters are more accurately estimated. Repeating the
process for $R$ = 5 reduces our ability to measure photon index ($\sim$3 to 8
per cent error and overestimated), but increases precision in all other
parameters -- most notably ionization, which becomes better constrained
($\pm$45 erg cm $\rm{s^{-1}}$) for low ionization parameters ($\xi$$<$200 erg
cm $\rm{s^{-1}}$). In all cases, we find the spin parameter is only well
measured for the most rapidly rotating supermassive black holes (i.e. $a$ $>$
0.8 to about $\pm$0.10) and that inner emissivity index is never well
constrained. Allowing our model to search for retrograde spin did not improve
the results.

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The categories of this paper are: quant-ph
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The categories of this paper are: funct-an
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The categories of this paper are: math-ph
2
The categories of this paper are: math
32
The categories of this paper are: atom-ph
35
The categories of this paper are: mtrl-th
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The categories of this paper are: solv-int
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The categories of this paper are: econ
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
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The categories of this paper are: q-alg
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The categories of this paper are: adap-org
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat