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Grand design and flocculent spirals in the Spitzer survey of stellar structure in galaxies (S⁴G)
- Source :
- ASTROPHYSICAL JOURNAL
- Publication Year :
- 2011
-
Abstract
- Spiral arm properties of 46 galaxies in the Spitzer Survey of Stellar Structure in Galaxies (S(4)G) were measured at 3.6 mu m, 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.
- Subjects :
- GRAVITATIONAL TORQUES
WAVE RESONANCES
DUST-PENETRATED CLASSIFICATION
Astrophysics::Cosmology and Extragalactic Astrophysics
OPTICAL TRACERS
GALAXIES
spiral [galaxies]
[infrared]
Physics and Astronomy
DRIVING MECHANISMS
BARRED
photometry [galaxies]
structure [galaxies]
NEARBY GALAXIES
Astrophysics::Earth and Planetary Astrophysics
INFRARED SURFACE PHOTOMETRY
PATTERN SPEEDS
Astrophysics::Galaxy Astrophysics
BAND OBSERVATIONS
Subjects
Details
- Language :
- English
- ISSN :
- 0004637X and 15384357
- Database :
- OpenAIRE
- Journal :
- ASTROPHYSICAL JOURNAL
- Accession number :
- edsair.od.......330..516072a0d345aec1327d1f27e9604b5a