Sources of scatter in the fundamental plane and the Dn-sigma relation

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view Abstract Citations (77) References (30) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Sources of Scatter in the Fundamental Plane and the D n- sigma Relation Jorgensen, Inger ; Franx, Marijn ; Kjaergaard, Per Abstract On the basis of new photometric data for early-type galaxies in the Coma Cluster we have determined the relation log r_e_ = α log σ + b<μ>_e_+ c known as the fundamental plane (FP). The scatter in the FP is equivalent to 11% uncertainty on distances. The residuals for the FP show no dependence on other available photometric and geometric parameters. Analysis of a nearby sample of ellipticals indicates that differences in dynamical structure for these galaxies may cause a scatter in the FP equivalent to 10% uncertainty on the distances. Thus, it may be possible to decrease the scatter by using the mean velocity dispersion within half the effective radius instead of the central velocity dispersion. The scatter in the D_n_-σ relation for the Coma Cluster galaxies is 17%, much higher than the 11% scatter for the FP. The residuals depend on the mean surface brightness. A similar result was obtained by Lucey, Bower, & Ellis, who used a linear fit in a restricted interval in <μ>_e_ in order to incorporate the effect in the distance determination. The D_n_-σ relation is an approximation to the FP, as first noted by Dressler et al. and Phillips. We find that the dependence on <μ>_e_ can be understood (without restrictions in <μ>_e_) as originating from this approximation. The FP projects into a slightly tilted and bended surface in the log D_n_-log σ-<μ>_e_ space. The available data in literature support this interpretation. Under the assumption that the FP is linear and the galaxies follow a de Vaucouleurs r^1/4^ law, the D_n_-σ relation can cause systematic errors of the order 10%-15% on distance determinations. It is possible that some existing discrepancies between distances determined from the D_n_-σ relation and from the Tully-Fisher method or the surface brightness fluctuation method are caused by the systematic errors of the D_n_-σ relation. There is no evidence that the large-scale motions in the universe derived by Lynden-Bell et al. on the basis of the D_n_-σ relation are severely affected by the systematic errors. We conclude that the FP is to be preferred as a distance indicator. Publication: The Astrophysical Journal Pub Date: July 1993 DOI: 10.1086/172805 Bibcode: 1993ApJ...411...34J Keywords: Astrometry; Astronomical Photometry; Elliptical Galaxies; Galactic Clusters; Red Shift; Galactic Evolution; Mass To Light Ratios; Universe; Astrophysics; GALAXIES: CLUSTERING; GALAXIES: DISTANCES AND REDSHIFTS; GALAXIES: ELLIPTICAL AND LENTICULAR; CD; GALAXIES: FUNDAMENTAL PARAMETERS; GALAXIES: PHOTOMETRY full text sources ADS | data products NED (52) SIMBAD (47)