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Date and Time of the Query: 2019-08-23 T22:16:07 PDT
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For refcode 1993A&AS..100..431G:
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Copyright by European Southern Observatory (ESO). Reproduced by permission
1993A&AS..100..431G Analysis of the distribution of HII regions in external galaxies. II. Analysis of the spiral structure C. Garcia Gomez and E. Athanassoula Observatoire de Marseille, 2 Place Le Verrier, F-13248 Marseille Cedex 4, France Received August 18; accepted December 2,1992 Abstract. - This paper is the second of a series where we study the distribution of HII regions in spiral galaxies. We use a Fourier decomposition to obtain the main spiral components of 44 galaxies, extracted from the sample of Garcia Gomez & Athanassoula (1991) as those having some structure in their HII region distribution. We recompose the density distribution using more than one component from each Fourier spectrum, thus obtaining more accurate results than in previous studies. We also study the dependences of the pitch angles of these components on other physical parameters of the galaxies, like the Hubble type and the arm class. Finally, for the galaxies where information on the flux of the HII regions is available, we use the Fourier decomposition to separate the HII regions in the arms from those in the interarm zones. The HII regions in the arms are, on the average, brighter by a factor of the order of 1.25 than those in the interarm. The brightest HII regions are preferentially located in the arms. Key words: galaxies: fundamental parameters - galaxies: general - galaxies: interstellar matter - galaxies: spiral
Retrieve 44 NED objects in this reference.
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