Bibcode
                                    
                            Edmunds, M. G.; Vílchez, J. M.; Terlevich, E.; Pagel, B. E. J.; Díaz, A. I.
    Referencia bibliográfica
                                    Revista Mexicana de Astronomia y Astrofisica, Vol. 21, p. 223 - 227
Fecha de publicación:
    
                        11
            
                        1990
            
  Número de citas
                                    8
                            Número de citas referidas
                                    4
                            Descripción
                                    Spectrophotometric data of giant H II regions covering the spectral
range from λ3600 to 9700 Å in the spiral galaxies M101 and
M51 have been analyzed in order to determine reliable chemical
abundances and radial gradients. The behaviour of the S/O ratio with
metallicity is also explored. The data are consistent, within the
errors, with a constant S/O abundance although uncertainties are large.