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Título:
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The galaxy major merger fraction to z ~ 1
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Autores:
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López Sanjuan, C. ;
Balcells, M. ;
Pérez González, Pablo Guillermo ;
Barro, Guillermo ;
García Dabó, C. E. ;
Gallego Maestro, Jesús ;
Zamorano Calvo, Jaime
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Tipo de documento:
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texto impreso
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Editorial:
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EDP Sciencies, 2009-07
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Dimensiones:
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application/pdf
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Nota general:
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info:eu-repo/semantics/openAccess
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Idiomas:
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Palabras clave:
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Estado = Publicado
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Materia = Ciencias: Física: Astrofísica
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Materia = Ciencias: Física: Astronomía
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Tipo = Artículo
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Resumen:
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Aims. The importance of disc-disc major mergers in galaxy evolution remains uncertain. We study the major merger fraction in a SPITZER/IRAC-selected catalogue in the GOODS-S field up to z ~ 1 for luminosity- and mass-limited samples. Methods. We select disc-disc merger remnants on the basis of morphological asymmetries/distortions, and address three main sources of systematic errors: (i) we explicitly apply morphological K-corrections; (ii) we measure asymmetries in galaxies artificially redshifted to z_d = 1.0 to deal with loss of morphological information with redshift; and (iii) we take into account the observational errors in z and A, which tend to overestimate the merger fraction, though use of maximum likelihood techniques. Results. We obtain morphological merger fractions (f_m^mph) below 0.06 up to z ~ 1. Parameterizing the merger fraction evolution with redshift as f_m^mph (z) = f_m^mph (0)(1 + z)^m, we find that m = 1.8 ± 0.5 for M(B)? -20 galaxies, while m = 5.4 ± 0.4 for M_* ? 10^10 M_? galaxies. When we translate our merger fractions to merger rates (R_m^mph), their evolution, parameterized as R_m^mph (z) = R_m^mph (0)(1+ z)^n, is quite similar in both cases: n = 3.3 ± 0.8 for M(B) ? -20 galaxies, and n = 3.5 ± 0.4 for M_* ?10^10 M_? galaxies. Conclusions. Our results imply that only similar to 8% of today's M(star) ? 10^10 M_? galaxies have undergone a disc-disc major merger since z ~ 1. In addition, ~ 21% of M_* ? 10(10) M_? galaxies at z ~ 1 have undergone one of these mergers since z similar to 1.5. This suggests that disc-disc major mergers are not the dominant process in the evolution of M_* ? 10(10) M_? galaxies since z 1, with only 0.2 disc-disc major mergers per galaxy, but may be an important process at z > 1, with ~ 1 merger per galaxy at 1
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En línea:
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https://eprints.ucm.es/34162/1/jesusgallego46libre.pdf
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