Elmegreen, Debra Meloy and Helou, George and Sheth, Kartik and Mizusawa, Trisha (2011) Grand Design and Flocculent Spirals in the Spitzer Survey of Stellar Structure in Galaxies (S^(4)G). Astrophysical Journal, 737 (1). Art. No. 32. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20110823-102753742
- Published Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20110823-102753742
Spiral arm properties of 46 galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S^(4)G) were measured at 3.6 μm, where extinction is small and the old stars dominate. The sample includes flocculent, multiple arm, and grand design types with a wide range of Hubble and bar types. We find that most optically flocculent galaxies are also flocculent in the mid-IR because of star formation uncorrelated with stellar density waves, whereas multiple arm and grand design galaxies have underlying stellar waves. Arm-interarm contrasts increase from flocculent to multiple arm to grand design galaxies and with later Hubble types. Structure can be traced further out in the disk than in previous surveys. Some spirals peak at mid-radius while others continuously rise or fall, depending on Hubble and bar type. We find evidence for regular and symmetric modulations of the arm strength in NGC 4321. Bars tend to be long, high amplitude, and flat-profiled in early-type spirals, with arm contrasts that decrease with radius beyond the end of the bar, and they tend to be short, low amplitude, and exponential-profiled in late Hubble types, with arm contrasts that are constant or increase with radius. Longer bars tend to have larger amplitudes and stronger arms.
|Additional Information:||© 2011 American Astronomical Society. Received 2011 March 22; accepted 2011 May 26; published 2011 July 26. We are grateful to the dedicated staff at the Spitzer Science Center for their help and support in planning and execution of this Exploration Science program. We also gratefully acknowledge support from NASA JPL/Spitzer grant RSA1374189 provided for the S4G project. D.M.E. gratefully acknowledges Vassar College for student support for Andrew Yau, and thanks NASA/JPL/Caltech for grant 1368024. E.A. and A.B. thank the Centre National d’Etudes Spatiales for financial support. This research is based in part on archival data obtained with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA, and has made use of the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. D.M.E. thanks Fred Chromey for writing the script to transform images into polar coordinates. We thank the referee for helpful comments on statistics.|
|Subject Keywords:||galaxies: photometry; galaxies: spiral; galaxies: structure; infrared: galaxies|
|Classification Code:||PACS: 98.52.Nr; 98.62.Ck; 98.62.Py; 98.35.Hj; 98.62.Ai; 98.62.Dm|
|Official Citation:||Grand Design and Flocculent Spirals in the Spitzer Survey of Stellar Structure in Galaxies (S4G) Debra Meloy Elmegreen et al. 2011 ApJ 737 32|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Jason Perez|
|Deposited On:||23 Aug 2011 21:16|
|Last Modified:||26 Dec 2012 13:30|
Repository Staff Only: item control page