Systematic effects and a new determination of the primordial abundance of He-4 and dY/dZ from observations of blue compact galaxies

Oct, 2003
53 pages
Published in:
  • Astrophys.J. 602 (2004) 200-230
e-Print:

Citations per year

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Abstract: (arXiv)
We use spectroscopic observations of a sample of 82 HII regions in 76 blue compact galaxies to determine the primordial helium abundance Yp and the slope dY/dZ from the Y-O/H linear regression. To improve the accuracy of the dY/dZ measurement, we have included new spectrophotometric observations of 33 HII regions which span a large metallicity range, with oxygen abundance 12+log(O/H) varying between 7.43 and 8.30 (Zsun/30
  • GALAXIES ABUNDANCES
  • GALAXIES IRREGULAR
  • GALAXIES ISM
  • HII REGIONS
  • ISM ABUNDANCES