NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-16 T13:33:51 PDT
Help | Comment | NED Home

For refcode 2009ApJ...694..115B:
Retrieve 33 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2009ApJ...694..115B Detection of Star Streams and Turbulence in Nearby Galaxies: Power Spectrum Analysis of Spitzer Images Block, D. L.; Puerari, I.; Elmegreen, B. G.; Elmegreen, D. M.; Fazio, G. G.; Gehrz, R. D. Abstract. Fourier transform power spectra of azimuthal scans in 33 galaxies imaged with the Infrared Array Camera on the Spitzer Space Telescope show an approximate power-law structure over a wide range of wavenumbers with a gradual steepening from 3.6 or 4.5 micron to 8.0 micron, in the order of an increasing contribution from gas and dust. At radii with active star formation, the average of the slopes of the 8 micron power spectra at intermediate spatial frequencies is about the same for all galaxies, independent of spiral arm morphology. These power spectra are reminiscent of turbulence, although the 8 micron slopes, averaging --2.0, are slightly steeper than expected (--1.7). Reconstructed images using only these intermediate spatial frequencies at 4.5 micron show aging star complexes distorted by shear. These sheared features illustrate the transition from a hierarchical structure during star formation into azimuthal star streams like the Pleiades moving group in the Solar neighborhood. This is the first time that young star streams have been observed in spiral galaxies other than the Milky Way. Key words: galaxies: evolution, galaxies: ISM, galaxies: spiral
Retrieve 33 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home