Resumen:
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The rate of major galaxy-galaxy merging is theoretically predicted to steadily increase with redshift during the peak epoch of massive galaxy development (1 2 x 10(10)M(circle dot)) hosting major companions (1 = 5 x 10(9)M(circle dot)) sample of 23 696 galaxies in the five Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey fields and the Sloan Digital Sky Survey. Using 5-50 kpc projected separation and close redshift proximity criteria, we find that the major companion fraction f(mc)(z) based on stellar mass-ratio (MR) selection increases from 6 per cent (z similar to 0) to 16 per cent (z similar to 0.8), then turns over at z similar to 1 and decreases to 7 per cent (z similar to 3). Instead, if we use a major F160W flux-ratio (FR) selection, we find that f(mc)(z) increases steadily until z similar to 3 owing to increasing contamination from minor (MR > 4: 1) companions at z > 1. We show that these evolutionary trends are statistically robust to changes in companion proximity. We find disagreements between published results are resolved when selection criteria are closely matched. If we compute merger rates using constant fraction-to-rate conversion factors (C-merg,C-pair = 0.6 and T-obs,T-pair = 0.65 Gyr), we find that MR rates disagree with theoretical predictions at z > 1.5. Instead, if we use an evolving T-obs,T-pair(z) alpha (1 + z)- 2 from Snyder et al., our MR-based rates agree with theory at 0
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