2010/04/30 by H. Salo, E. Laurikainen, R. Buta +1 · 1 citation
Mathematics · Physics and Astronomy · #Amplitude #Astronomy and Astrophysical Research #Astrophysics #Bar (unit) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Mathematical analysis #Mathematics #Optics #Physics #Spiral (railway) #Spiral galaxy #Stellar, planetary, and galactic studies #astro-ph.CO
paper · pdf · doi:10.1088/2041-8205/715/1/l56
Accepted to ApJL
arxiv created 2010/04/30 · openalex publication_date 2010/05/03 · arxiv updated 2015/05/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recently, Buta et al. examined the question "Do Bars Drive Spiral Density Waves?", an idea supported by theoretical studies and also from a preliminary observational analysis. They estimated maximum bar strengths Q b , maximum spiral strengths Q s , and maximum m = 2 arm contrasts A 2 s for 23 galaxies with deep Anglo-Australian Telescope (AAT) K s -band images. These were combined with previously published Q b and Q s values for 147 galaxies from the Ohio State University Bright Spiral Galaxy Survey (OSUBSGS) sample and with the 12 galaxies from Block et al. Weak correlation between Q b and Q s was confirmed for the combined sample, whereas the AAT subset alone showed no significant correlations between Q b and Q s , nor between Q b and A 2 s . A similar negative result was obtained in Durbala et al. for 46 galaxies. Based on these studies, the answer to the above question remains uncertain. Here we use a novel approach, and show that although the correlation between the maximum bar and spiral parameters is weak, these parameters do correlate when compared locally . For the OSUBSGS sample, a statistically significant correlation is found between the local spiral amplitude, and the forcing due to the bar's potential at the same distance, out to ≈1.6 bar radii (the typical bar perturbation is then of the order of a few percent). Also for the sample of 23 AAT galaxies of Buta et al., we find a significant correlation between local parameters out to ≈1.4 bar radii. Our new results confirm that, at least in a statistical sense, bars do indeed drive spiral density waves.