INVESTIGADORES
DIAZ Maria Eugenia
artículos
Título:
Two Degree Field Galaxy Redshift Survey and Sloan Digital Sky Survey Galaxy Group Density Profiles
Autor/es:
DÍAZ, EUGENIA; ZANDIVAREZ, ARIEL; MERCHÁN, MANUEL E.; MURIEL, HERNÁN
Revista:
ASTROPHYSICAL JOURNAL
Referencias:
Año: 2005 vol. 629 p. 158 - 171
ISSN:
0004-637X
Resumen:
We have analyzed the distribution of galaxies in groups identified in
the largest redshift surveys available at present: the final release of
the 2dF Galaxy Redshift Survey and the first release of the Sloan
Digital Sky Survey. Our work comprises the study of the galaxy density
profiles and the fraction of galaxies per spectral type as a function of
the groupcentric distance. We have calculated the projected galaxy
density profiles of galaxy groups using composite samples in order to
increase the statistical significance of the results. Special care has
been taken in order to avoid possible biases in the group identification
and the construction of the projected galaxy density profile estimator.
The results show that the projected galaxy density profiles obtained for
both redshift surveys are in agreement with a projected Navarro, Frenk,
and White prediction in the range 0.15<r/r200<1,
whereas a good fit for the measured profiles in the whole range of
r/r200 is given by a projected King profile. We have adopted
a generalized King profile to fit the measured projected density
profiles per spectral type. In order to infer the three-dimensional
galaxy density profiles, we deproject the two-dimensional density
profiles using a deprojection method similar to that developed by Allen
and Fabian. From two-dimensional and three-dimensional galaxy density
profiles, we have estimated the corresponding galaxy fractions per
spectral type. The two-dimensional fraction of galaxies computed using
the projected profiles shows a similar segregation of galaxy spectral
types as that obtained by Domínguez and coworkers for groups in
the early data release of the 2dF Galaxy Redshift Survey. As expected,
the trends obtained for the three-dimensional galaxy fractions show
steeper slopes than those observed in the two-dimensional fractions.