Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Maximum Likelihood Fitting of Tidal Streams With Application to the
  Sagittarius Dwarf Tidal Tails   We present a maximum likelihood method for determining the spatial properties
of tidal debris and of the Galactic spheroid. With this method we characterize
Sagittarius debris using stars with the colors of blue F turnoff stars in SDSS
stripe 82. The debris is located at (alpha, delta, R) = (31.37 deg +/- 0.26
deg, 0.0 deg, 29.22 +/- 0.20 kpc), with a (spatial) direction given by the unit
vector < -0.991 +/- 0.007 kpc, 0.042 +/- 0.033 kpc, 0.127 +/- 0.046 kpc >, in
Galactocentric Cartesian coordinates, and with FWHM = 6.74 +/- 0.06 kpc. This
2.5 degee-wide stripe contains 0.9% as many F turnoff stars as the current
Sagittarius dwarf galaxy. Over small spatial extent, the debris is modeled as a
cylinder with a density that falls off as a Gaussian with distance from the
axis, while the smooth component of the spheroid is modeled with a Hernquist
profile. We assume that the absolute magnitude of F turnoff stars is
distributed as a Gaussian, which is an improvement over previous methods which
fixed the absolute magnitude at Mg0 = 4.2. The effectiveness and correctness of
the algorithm is demonstrated on a simulated set of F turnoff stars created to
mimic SDSS stripe 82 data, which shows that we have a much greater accuracy
than previous studies. Our algorithm can be applied to divide the stellar data
into two catalogs: one which fits the stream density profile and one with the
characteristics of the spheroid. This allows us to effectively separate tidal
debris from the spheroid population, both facilitating the study of the tidal
stream dynamics and providing a test of whether a smooth spheroidal population
exists.

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The categories of this paper are: cs
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The categories of this paper are: math-ph
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The categories of this paper are: math
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
29
The categories of this paper are: funct-an
37
The categories of this paper are: supr-con
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
15
The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th