Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the size and location of the X-ray emitting coronae around black
  holes   The observation of energetic X-ray emission from black holes, inconsistent
with thermal emission from an accretion disk, has long indicated the presence
of a "corona" around these objects. However, our knowledge of the geometry,
composition, and processes within black hole coronae is severely lacking. Basic
questions regarding their size and location are still a topic of debate. In
this letter, we show that for black holes with luminosities
$L\gtrsim10^{-2}L_{Edd}$ -- characteristic of many Seyferts, quasars, and
stellar-mass black holes (in their brighter states) -- advanced imaging and
timing data strongly favor X-ray emitting regions that are highly compact, and
only a few Gravitational radii above the accretion disk. The inclusion of a
large number of possible systematics uncertainties does not significantly
change this conclusion with our results still suggesting emission from within
$\sim20$\rg\ in all cases. This result favors coronal models wherein most of
the hard X-ray emission derives from magnetic reconnection in the innermost
disk and/or from processes in the compact base of a central, relativistic jet.

13
The categories of this paper are: quant-ph
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
15
The categories of this paper are: nucl-ex
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
2
The categories of this paper are: math
26
The categories of this paper are: bayes-an