Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The evolution of planetary nebulae VII. Modelling planetary nebulae of
  distant stellar systems   By means of hydrodynamical models we do the first investigations of how the
properties of planetary nebulae are affected by their metal content and what
can be learned from spatially unresolved spectrograms of planetary nebulae in
distant stellar systems. We computed a new series of 1D radiation-hydrodynamics
planetary nebulae model sequences with central stars of 0.595 M_sun surrounded
by initial envelope structures that differ only by their metal content. At
selected phases along the evolutionary path, the hydrodynamic terms were
switched off, allowing the models to relax for fixed radial structure and
radiation field into their equilibrium state with respect to energy and
ionisation. The analyses of the line spectra emitted from both the dynamical
and static models enabled us to systematically study the influence of
hydrodynamics as a function of metallicity and evolution. We also recomputed
selected sequences already used in previous publications, but now with
different metal abundances. These sequences were used to study the expansion
properties of planetary nebulae close to the bright cut-off of the planetary
nebula luminosity function. Our simulations show that the metal content
strongly influences the expansion of planetary nebulae: the lower the metal
content, the weaker the pressure of the stellar wind bubble, but the faster the
expansion of the outer shell because of the higher electron temperature. This
is in variance with the predictions of the interacting-stellar-winds model (or
its variants) according to which only the central-star wind is thought to be
responsible for driving the expansion of a planetary nebula. Metal-poor objects
around slowly evolving central stars become very dilute and are prone to depart
from thermal equilibrium because then adiabatic expansion contributes to gas
cooling. ...abridged abstract.

1
The categories of this paper are: cs
12
The categories of this paper are: nucl-th
4
The categories of this paper are: cond-mat
2
The categories of this paper are: math
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
16
The categories of this paper are: stat
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc