ARRAKIS: atlas of resonance rings as known in the S4G⋆
1 University of Oulu, Astronomy Division, Department of Physics, PO Box 3000, 90014 Oulu, Finland
2 Finnish Centre of Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
3 Korea Astronomy and Space Science Institute, 776, Daedeokdae-ro, Yuseong-gu, 305-348 Daejeon, Republic of Korea
4 Instituto de Astrofísica de Canarias, 38205 La Laguna, Tenerife, Spain
5 Departamento de Astrofísica, Universidad de La Laguna, 38200 La Laguna, Tenerife, Spain
6 Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487, USA
7 European Space Agency, ESTEC, Keplerlaan 1, 2200 AG Noorwijk, The Netherlands
8 National Radio Astronomy Observatory/NAASC, 520 Edgemont Road, Charlottesville, VA 22903, USA
9 Space Telescope Science Institute, 3700 San Antonio Drive, Baltimore, MD 21218, USA
10 European Southern Observatory, 19001 Casilla, Santiago 19, Chile
11 MMTO, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721, USA
12 Departamento de Astrofísica, Universidad Complutense de Madrid, 28040 Madrid, Spain
13 Universidade Federal do Rio de Janeiro, Observatório do Valongo, Ladeira Pedro Antônio, 43, CEP 20080-090 Rio de Janeiro, Brazil
14 The Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101, USA
15 Florida Institute of Technology, Melbourne, FL 32901, USA
16 Astronomy Program, Department of Physics and Astronomy, Seoul National University, 151-742 Seoul, Republic of Korea
17 Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
18 Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing, PR China
Received: 3 April 2013
Accepted: 2 December 2013
Context. Resonance rings and pseudorings (here collectively called rings) are thought to be related to the gathering of material near dynamical resonances caused by non-axisymmetries in galaxy discs. This means that they are the result of secular evolution processes that redistribute material and angular momentum in discs. Studying them may give clues on the formation and growth of bars and other disc non-axisymmetries.
Aims. Our aims are to produce a catalogue and an atlas of the rings detected in the Spitzer Survey of Stellar Structure in Galaxies (S4G) and to conduct a statistical study of the data in the catalogue.
Methods. We traced the contours of rings previously identified and fitted them with ellipses. We found the orientation of bars by studying the galaxy ellipse fits from the S4G pipeline 4. We used the galaxy orientation data obtained by the S4G pipeline 4 to obtain intrinsic ellipticities and orientations of rings and the bars.
Results. ARRAKIS contains data on 724 ringed galaxies in the S4G. The frequency of resonance rings in the S4G is of 16 ± 1% and 35 ± 1% for outer and inner features, respectively. Outer rings are mostly found in Hubble stages − 1 ≤ T ≤ 4. Inner rings are found in a broad distribution that covers the range − 1 ≤ T ≤ 7. We confirm that outer rings have two preferred orientations, namely parallel and perpendicular to the bar. We confirm a tendency for inner rings to be oriented parallel to the bar, but we report the existence of a significant fraction (maybe as large as 50%) of inner features that have random orientations with respect to the bar. These misaligned inner rings are mostly found in late-type galaxies (T ≥ 4). We find that the fraction of barred galaxies hosting outer (inner) rings is ~1.7 times (~1.3 times) that in unbarred galaxies.
Conclusions. We confirm several results from previous surveys as well as predictions from simulations of resonant rings and/or from manifold flux tube theory. We report that a significant fraction of inner rings in late-type galaxies have a random orientation with respect to the bar. This may be caused by spiral modes that are decoupled from the bar and dominate the Fourier amplitude spectrum at the radius of the inner ring. The fact that rings are only mildly favoured by bars suggests that those in unbarred galaxies either formed because of weak departures from the axisymmetry of the galactic potential or that they are born because of bars that were destroyed after the ring formation.
Key words: atlases / catalogs / galaxies: statistics / galaxies: structure
Tables A.1 and A.2 (catalogue) are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (188.8.131.52) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/562/A121
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