2005/05/05 by M. Kalinkov, T. Valchanov, I. Valtchanov +2
Physics and Astronomy · #Astronomy and Astrophysical Research #Cluster (spacecraft) #Field (mathematics) #Fundamental plane (elliptical galaxies) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy rotation curve #Rotation (mathematics) #Scientific Research and Discoveries #Virial mass #Virial theorem #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09008.x
published as Mon.Not.Roy.Astron.Soc. 359 (2005) 1491-1497 · 7 pages, 9 figures gzipped tar file. to be published in MNRAS
arxiv created 2005/05/05 · openalex publication_date 2005/05/27 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present indications of rotation in the galaxy cluster A2107 by a method that searches for the maximum gradient in the velocity field in a flat disc-like model of a cluster. Galaxies from cumulative subsamples containing more and more distant members from the cluster centre are projected on to an axis passing through the centre and we apply a linear regression model on the projected distances x and the line-of-sight velocities V. The axis with the maximum linear correlation coefficient rmax = max[r(V, x)] defines the direction of the maximum velocity gradient, and consequently it presents the major axis of the apparently elliptical cluster. Because the effects of rotation are subtle, we put strong emphasis on the estimation of the uncertainties of the results by implementing different bootstrap techniques. We have found that rotational effects are more strongly expressed at distances of 0.26–0.54 Mpc from the cluster centre. The total virial mass of the cluster is (3.2 ± 0.6) × 1014 M⊙, while the virial mass, corrected for rotation, is (2.8 ± 0.5) × 1014 M⊙.