Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Balance among gravitational instability, star formation, and accretion
  determines the structure and evolution of disk galaxies   Over the past 10 Gyr, star-forming galaxies have changed dramatically, from
clumpy and gas rich, to rather quiescent stellar-dominated disks with specific
star formation rates lower by factors of a few tens. We present a general
theoretical model for how this transition occurs, and what physical processes
drive it, making use of 1D axisymmetric thin disk simulations with an improved
version of the Gravitational Instability-Dominated Galaxy Evolution Tool
(GIDGET) code. We show that at every radius galaxies tend to be in a slowly
evolving equilibrium state wherein new accretion is balanced by star formation,
galactic winds, and radial transport of gas through the disk by gravitational
instability (GI) -driven torques. The gas surface density profile is determined
by which of these terms are in balance at a given radius - direct accretion is
balanced by star formation and galactic winds near galactic centers, and by
transport at larger radii. We predict that galaxies undergo a smooth transition
from a violent disk instability phase to secular evolution. This model provides
a natural explanation for the high velocity dispersions and large clumps in z~2
galaxies, the growth and subsequent quenching of bulges, and features of the
neutral gas profiles of local spiral galaxies.

15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin
0
The categories of this paper are: hep-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
32
The categories of this paper are: atom-ph
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph