Bibcode
Vicente, B.; Garzon, F.
Bibliographical reference
Highlights of Spanish Astrophysics VI, Proceedings of the IX Scientific Meeting of the Spanish Astronomical Society (SEA), held in Madrid, September 13 - 17, 2010, Eds.: M. R. Zapatero Osorio, J. Gorgas, J. Maíz Apellániz, J. R. Pardo, and A. Gil de Paz., p. 552-552
Advertised on:
11
2011
Citations
0
Refereed citations
0
Description
The luminosity function is not only crucial to know the stellar density
distribution in space, and thus to know the structure of the Galaxy; it
also allows the determination of the stellar mass function using the
mass-luminosity relationship. The luminosity and mass functions are
crucial to understand star formation and the evolution of the Milky Way.
It is customary to assume that the luminosity function in the solar
neighborhood, which can be obtained directly from precise star counts,
represents well that of the Galactic disk, if not the whole Milky Way
and similar external galaxies. Under this assumption, we simply need to
calculate in the solar vicinity and then move it to the disk area of
interest. In this regard, the larger the sample used for determining
more reliable is the extrapolation to galactic studies. We have
determined the luminosity function in the solar neighborhood up to 200
pcs considering the proper motions as distance estimators. We used the
parameter ``reduced proper motion'' (Luyten 1938) for calibration of the
apparent magnitudes to absolute ones. This calibration must be done with
kinematically similar populations, i.e., they share the same velocity
distribution. So, prior to calculating the luminosity determination we
used the SKY model (Wainscoat et al. 1992) to separate stars with
different kinematic evolution in our catalogue. As our kinematical
database, we used the CdC-SF Catalogue (Vicente et al. 2010), which has
proper motion precision similar to that of Hipparcos but to much fainter
magnitudes (V=15). Such a rich data allow getting the luminosity
function for distances greater than those identified so far by extending
existing results. Have greater distances involved have information of
the luminosity function for stars more luminous, since the number of
bright stars near the sun is quite low. Also, a larger sample with
smaller proper motions produce a luminosity function more adapted to the
real Galaxy model due to decrease the correction factor of completeness.