Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Environment and mass dependencies of galactic $\lambda$ spin parameter:
  cosmological simulations and observed galaxies compared   We use a sample of galaxies from the Sloan Digital Sky Survey (SDSS) to
search for correlations between the $\lambda$ spin parameter and the
environment and mass of galaxies. In order to calculate the total value of
$\lambda$ for each observed galaxy, we employed a simple model of the dynamical
structure of the galaxies, which allows a rough estimate of the value of
$\lambda$ using only readily obtainable observables from the luminous galaxies.
Use of a large volume-limited sample (upwards of 11,000) allows reliable
inferences of mean values and dispersions of $\lambda$ distributions. We find,
in agreement with some N-body cosmological simulations, no significant
dependence of $\lambda$ on the environmental density of the galaxies. For the
case of mass, our results show a marked correlation with $\lambda$, in the
sense that low-mass galaxies present both higher mean values of $\lambda$ and
associated dispersions, than high-mass galaxies. These results provide
interesting constrain on the mechanisms of galaxy formation and acquisition of
angular momentum, a valuable test for cosmological models.

15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
3
The categories of this paper are: physics
18
The categories of this paper are: econ
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
2
The categories of this paper are: math