2003/07/04 by Victor P. Debattista · 7 citations
Environmental Science · Mathematics · Physics and Astronomy · #Morphological variations and asymmetry #Soil Geostatistics and Mapping #Statistical and numerical algorithms #astro-ph
paper · pdf · doi:10.1046/j.1365-8711.2003.06620.x
published as Mon.Not.Roy.Astron.Soc. 342 (2003) 1194 · 12 pages, 13 figures. Appeared in July 2003 issue of MNRAS
openalex publication_date 2003/07/04 · arxiv created 2004/01/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
I show that Tremaine–Weinberg (TW) measurements of bar pattern speeds are sensitive to errors in the position angle of the disc, PAdisc. I use an N-body experiment to measure these errors; for typical random PAdisc errors, the resulting scatter in the measured values of the dimensionless bar speed parameter (defined as the ratio of the corotation radius to the bar semi-major axis) is of the order of the scatter in the observed values. I also consider how the systematic PAdisc errors produced by disc ellipticities affect TW measurements. The scatter produced by these errors may be significant, depending on the ellipticity distribution. Conversely, by using the sample of TW observations, I find that an upper limit of the typical disc (density) ellipticity is 0.07 at the 90 per cent confidence level, which is in good agreement with previous measurements. Taken together, the random and systematic scatter suggest that the intrinsic distribution of of gas-poor early-type barred galaxies may be as narrow as that of the gas-rich later types.