The Millennium Galaxy Catalogue: Dynamically Close Galaxy Pairs and the Global Merger Rate

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dc.creatorDe Propris, R.
dc.creatorLiske, J.
dc.creatorDriver, S. P.
dc.creatorAllen, P.
dc.creatorCross, N. J. G.
dc.date2005-06-27
dc.date.accessioned2026-07-07T11:24:30Z
dc.date.available2026-07-07T11:24:30Z
dc.descriptionWe derive the number of dynamically close companions per galaxy ($N_c$) and their total luminosity ($L_c$) for galaxies in the Millennium Galaxy Catalogue: $N_c$ is similar to the fraction of galaxies in close pairs and is directly related to the galaxy merger rate. We find $N_c=0.0174 \pm 0.0015$ and $L_c=(252 \pm 30) \times 10^6$ $L_{\odot}$ for galaxies with $-22 < M_B -5 \log h < -19$ with $<z>=0.123$ and $N_c=0.0357 \pm 0.0027$, $L_c= (294 \pm 31) \times 10^6 L_{\odot}$ for galaxies with $-21 < M_B -5 \log h < -18$, with $<z>=0.116$. The integrated merger rate to $z=1$ for both samples is about 20 %, but this depends sensitively on the fraction of kinematic pairs that are truly undergoing a merger (assumed here to be 50%), the evolution of the merger rate (here as $(1+z)^3$) and the adopted timescale for mergers (0.2 and 0.5 Gyr for each sample, respectively). Galaxies involved in mergers tend to be marginally bluer than non-interacting galaxies and show an excess of both early-type and very late-type objects and a deficiency of intermediate-type spirals. This suggests that interactions and mergers partly drive the star formation and morphological evolution of galaxies.
dc.description26 pages, 3 figures, AJ accepted for publication
dc.identifierhttps://arxiv.org/abs/astro-ph/0506635
dc.identifierhttp://arxiv.org/abs/astro-ph/0506635
dc.identifierAstron.J.130:1516,2005
dc.identifierdoi:10.1086/433169
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/195215
dc.subjectAstrophysics
dc.titleThe Millennium Galaxy Catalogue: Dynamically Close Galaxy Pairs and the Global Merger Rate
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