2008/04/01 by A. Rawat, F. Hammer, Francois Hammer +4 · 1 citation
Physics and Astronomy · #Absolute magnitude #Adaptive optics and wavefront sensing #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Luminosity #Photometry (optics) #Physics #Redshift #Star formation #Stars #Stellar mass #astro-ph
paper · pdf · doi:10.1086/588774
Accepted for Publication in ApJ. 9 Figures
arxiv created 2008/04/01 · openalex publication_date 2008/07/10 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We use a combination of deep, high angular resolution imaging data from the CDFS ( HST /ACS GOODS survey) and ground-based near-IR K s images to derive the evolution of the galaxy major merger rate in the redshift range 0.2 ⩽ z⩽ 1.2. We select galaxies solely on the basis of their J -band rest-frame absolute magnitude, which is a good tracer of the stellar mass. We find steep evolution with redshift, with the merger rate ∝(1 + z) 3.43 ± 0.49 for optically selected pairs and ∝(1 + z) 2.18 ± 0.18 for pairs selected in the near-IR. Our result is unlikely to be affected by luminosity evolution that is relatively modest when using rest-frame J -band selection. The apparently more rapid evolution that we find in the visible is likely caused by biases relating to incompleteness and spatial resolution affecting the ground-based near-IR photometry, underestimating pair counts at higher redshifts in the near-IR. The major merger rate was ~5.6 times higher at z ∼ 1.2 than at the current epoch. Overall, 41% × (0.5 Gyr/τ) of all galaxies with M J ⩽ − 19.5 have undergone a major merger in the last ~8 Gyr, where τ is the merger timescale. Interestingly, we find no effect on the derived major merger rate due to the presence of the large-scale structure at z = 0.735 in the CDFS.