Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A backwards approach to the formation of disk galaxies I. Stellar and
  gas content   A simple chemical enrichment code is described where the two basic mechanisms
driving the evolution of the ages and metallicities of the stellar populations
are the star formation efficiency and the fraction of gas ejected from the
galaxy. Using the observed Tully-Fisher relation in different passbands as a
constraint, it is found that a steep correlation between the maximum disk
rotational velocity and star formation efficiency must exist either for a
linear or a quadratic Schmidt law. Outflows do not play a major role. The
redshift evolution of disk galaxies is explored, showing that a significant
change in the slope of the Tully-Fisher relation is expected because of the
different age distributions of the stellar components in high and low-mass disk
galaxies. The slope measured in the rest frame B,K bands is found to change
from 3(B); 4(K) at z=0 up to 4.5(B); 5(K) at z~1, with a slight dependence on
formation redshift.

2
The categories of this paper are: math
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
36
The categories of this paper are: cmp-lg
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
16
The categories of this paper are: stat