Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Origin of asymmetries in X-ray emission lines from the blast wave of the
  2014 outburst of nova V745 Sco   The symbiotic nova V745 Sco was observed in outburst on 2014 February 6. Its
observations by the Chandra X-ray Observatory at days 16 and 17 have revealed a
spectrum characterized by asymmetric and blue-shifted emission lines. Here we
investigate the origin of these asymmetries through three-dimensional
hydrodynamic simulations describing the outburst during the first 20 days of
evolution. The model takes into account thermal conduction and radiative
cooling and assumes a blast wave propagates through an equatorial density
enhancement. From the simulations, we synthesize the X-ray emission and derive
the spectra as they would be observed with Chandra. We find that both the blast
wave and the ejecta distribution are efficiently collimated in polar directions
due to the presence of the equatorial density enhancement. The majority of the
X-ray emission originates from the interaction of the blast with the equatorial
density enhancement and is concentrated on the equatorial plane as a ring-like
structure. Our "best-fit" model requires a mass of ejecta in the outburst
$M_{ej} \approx 3\times 10^{-7}\,M_{\odot}$ and an explosion energy $E_b
\approx 3 \times 10^{43}$ erg and reproduces the distribution of emission
measure vs temperature and the evolution of shock velocity and temperature
inferred from the observations. The model predicts asymmetric and blue-shifted
line profiles similar to those observed and explains their origin as due to
substantial X-ray absorption of red-shifted emission by ejecta material. The
comparison of predicted and observed Ne and O spectral line ratios reveals no
signs of strong Ne enhancement and suggests the progenitor is a CO white dwarf.

24
The categories of this paper are: dg-ga
4
The categories of this paper are: cond-mat
9
The categories of this paper are: nlin
2
The categories of this paper are: math
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
17
The categories of this paper are: q-fin
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
21
The categories of this paper are: adap-org
11
The categories of this paper are: hep-lat