IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
artículos
Título:
Building a control sample for galaxy pairs
Autor/es:
PEREZ, J; TISSERA, P. B.; BLAIZOT, J.
Revista:
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2009 vol. 397 p. 748 - 756
ISSN:
0035-8711
Resumen:
Several observational works have attempted to isolate the effects of
galaxy interactions by comparing galaxies in pairs with isolated
galaxies. However, different authors have proposed different ways to
build these so-called control samples (CS). By using mock galaxy
catalogues of the Sloan Digital Sky Survey Data Release 4 buildup from
the Millennium Simulation, we explore how the way of building a CS might
introduce biases which could affect the interpretation of results. We
make use of the fact that the physics of interactions are not included
in the semi-analytic model, to infer that any difference between the
mock control and pair samples can be ascribed to selection biases. Thus,
we find that galaxies in pairs artificially tend to be older and more
bulge dominated, and to have less cold gas and different metallicities
than their isolated counterparts. Also because of a biased selection,
galaxies in pairs tend to live in higher density environments and in
haloes of larger masses. We find that imposing constraints on redshift,
stellar masses and local densities diminishes the selection biases by
~70per cent. Based on these findings, we suggest observers how to build
a unique and unbiased CS in order to reveal the effect of galaxy
interactions.