Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A unified picture of breaks and truncations in spiral galaxies from SDSS
  and S^{4}G imaging   The mechanism causing breaks in the radial surface brightness distribution of
spiral galaxies is not yet well known. Despite theoretical efforts, there is
not a unique explanation for these features and the observational results are
not conclusive. In an attempt to address this problem, we have selected a
sample of 34 highly inclined spiral galaxies present both in the Sloan Digital
Sky Survey and in the Spitzer Survey of Stellar Structure in Galaxies. We have
measured the surface brightness profiles in the five Sloan optical bands and in
the 3.6$\mu m$ Spitzer band. We have also calculated the color and stellar
surface mass density profiles using the available photometric information,
finding two differentiated features: an innermost break radius at distances of
$\sim 8 \pm 1$ kpc [$0.77 \pm 0.06$ $R_{25}$] and a second characteristic
radius, or truncation radius, close to the outermost optical extent ($\sim 14
\pm 2$ kpc [$1.09 \pm 0.05$ $R_{25}$]) of the galaxy. We propose in this work
that the breaks might be a phenomena related to a threshold in the star
formation, while truncations are more likely a real drop in the stellar mass
density of the disk associated with the maximum angular momentum of the stars.

20
The categories of this paper are: acc-phys
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
14
The categories of this paper are: math-ph
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
10
The categories of this paper are: q-bio