W. J. Maciel - Abstract #86


SOME ASPECTS OF THE CHEMICAL EVOLUTION OF 4He IN THE GALAXY: THE He/H RADIAL GRADIENT AND THE Delta Y/Delta Z ENRICHMENT RATIO

W. J. Maciel

IAU Symposium 198, The light elements and their evolution, ed. L. da Silva, M. Spite, J. R. de Medeiros ASP, 204-213 (2000)

Two aspects of the chemical evolution of 4He in the Galaxy are considered on the basis of a sample of disk planetary nebulae by the application of corrections due to the contamination of 4He from the progenitor stars. First, the He/H radial gradient is analyzed, and then, the helium to heavy element enrichment ratio is determined for metallicities up to the solar value.

back to W. J. Maciel Homepage back to W. J. Maciel/Research