2004/02/07 by C. K. Xu, Y. C. Sun, X. T. He · 6 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Fundamental plane (elliptical galaxies) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Gamma-ray bursts and supernovae #Luminosity #Luminosity function #Luminous infrared galaxy #Radio galaxy #Redshift #Stellar mass #astro-ph
paper · pdf · doi:10.1086/383223
published as Astrophys.J. 603 (2004) L73-L76 · Accepted by ApJL, 16 pages, 2 figures
arxiv created 2004/02/07 · openalex publication_date 2004/02/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A sample of close major-merger pairs (projected separation 5 h -1 kpc ≤ r ≤ 20 h -1 kpc, K s -band magnitude difference δ K s ≤ 1 mag) is selected from the matched Two Micron All Sky Survey (2MASS)/Two-Degree Field Galaxy Redshift Survey catalog of Cole et al. The pair primaries are brighter than K s = 12.5 mag. After corrections for various biases, the comparison between counts in the paired galaxy sample and counts in the parent sample shows that for the local " M * galaxies" sampled by flux-limited surveys, the fraction of galaxies in the close major-merger pairs is 1.70% ± 0.32%. Using 38 paired galaxies in the sample, a K s -band luminosity function (LF) is calculated. This is the first unbiased LF for a sample of objectively defined interacting/merging galaxies in the local universe, while all previously determined LFs of paired galaxies are biased by mistreating paired galaxies as singles. A stellar mass function (MF) is translated from the LF. Compared to the LF/MF of 2MASS galaxies, a differential pair fraction function is derived. The results suggest a trend in the sense that less massive galaxies may have a lower chance to be involved in close major-merger pairs than more massive galaxies. The algorithm presented in this Letter can be easily applied to much larger samples of 2MASS galaxies with redshifts in the near future.