C.D.S. - SIMBAD4 rel 1.7 - 2021.01.24CET02:07:32

2009A&A...501..505L - Astronomy and Astrophysics, volume 501, 505-518 (2009/7-2)

The galaxy Major merger fraction to z ∼1.


Abstract (from CDS):

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. 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 zd=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. We obtain morphological merger fractions (fmmph) below 0.06 up to z ∼1. Parameterizing the merger fraction evolution with redshift as fmmph(z)=fmmph(0)(1+z)m, we find that m=1.8±0.5 for MB≤-20 galaxies, while m=5.4±0.4 for M*≥1010M galaxies. When we translate our merger fractions to merger rates (Rmmph), their evolution, parameterized as Rmmph(z)=Rmmph(0)(1+z)n, is quite similar in both cases: n=3.3±0.8 for MB≤-20 galaxies, and n=3.5±0.4 for M*≥1010M galaxies. Our results imply that only ∼8% of today's M*≥1010M galaxies have undergone a disc-disc major merger since z∼1. In addition, ∼21% of M*≥1010M galaxies at z∼1 have undergone one of these mergers since z∼1.5. This suggests that disc-disc major mergers are not the dominant process in the evolution of M*≥1010M 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<z<3.

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Journal keyword(s): galaxies: evolution - galaxies: formation - galaxies: interactions - galaxies: statistics

Simbad objects: 4

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Number of rows : 4

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
1 NAME GOODS Southern Field reg 03 32 28.0 -27 48 30           ~ 1103 1
2 NAME Hubble Ultra Deep Field reg 03 32 39.0 -27 47 29           ~ 1332 0
3 NAME Hubble Deep Field reg 12 36 49.5 +62 12 58           ~ 1840 1
4 NAME Extended Groth Strip reg 14 19 +52.8           ~ 604 0

    Equat.    Gal    SGal    Ecl

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