Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: New Spectral State of Supercritical Accretion Flow with Comptonizing
  Outflow   Supercritical accretion flows inevitably produce radiation-pressure driven
outflows, which will Compton up-scatter soft photons from the underlying
accretion flow, thereby making hard emission. We perform two dimensional
radiation hydrodynamic simulations of supercritical accretion flows and
outflows, incorporating such Compton scattering effects, and demonstrate that
there appears a new hard spectral state at higher photon luminosities than that
of the slim-disk state. In this state, as the photon luminosity increases, the
photon index decreases and the fraction of the hard emission increases. The
Compton $y$-parameter is of the order of unity (and thus the photon index will
be $\sim 2$) when the apparent photon luminosity is ${\sim}30L_{\rm E}$ (with
$L_{\rm E}$ being the Eddington luminosity) for nearly face-on sources. This
explains the observed spectral hardening of the ULX NGC1313 X-2 in its
brightening phase and thus supports the model of supercritical accretion onto
stellar mass black holes in this ULX.

14
The categories of this paper are: math-ph
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-bio