The nature of arms in spiral galaxies. II. The sample

del Río, M. S.; Cepa, J.
Referencia bibliográfica

Astronomy and Astrophysics, v.400, p.421-428 (2003)

Fecha de publicación:
3
2003
Número de autores
2
Número de autores del IAC
1
Número de citas
1
Número de citas referidas
1
Descripción
We present here the results of an imaging study of eight grand-design and two intermediate-arm galaxies, based on CCD observations in U, B, V, R and I. We give grey-scale images, both in individual and in colour indices. Also we present a decomposition into bulge and disc following an iterative method. This provides us with a reasonable estimate of the bulge size and disc scale length, and shows the disc deviation from an exponential law, which can be interpreted as due to the long-term star formation caused by the spiral arms. To evaluate the contribution of the spiral arms to the disc luminosity distribution, with the aid of a mask we have decomposed each image into two parts: arms (which include bulge and nucleus, and eventually bars) and inter-arms (which include the outer disc). In subsequent papers in this series (del Río & Cepa cite{del1998}, hereafter Paper III; del Río & Cepa cite{del1999}, hereafter Paper IV) the data presented here are used to analyse the spiral structure of the galaxies of the sample, using the methods of Beckman & Cepa (cite{Beckman}, hereafter Paper I) and the Fourier transform method to find the different symmetry degrees. Figures 1 to 4 and Fig. 7 are only available in electronic form at http://www.edpsciences.org}