Journal Article

The effect of stellar evolution uncertainties on the rest-frame ultraviolet stellar lines of C <span class="smallCaps">iv</span> and He <span class="smallCaps">ii</span> in high-redshift Lyman-break galaxies

John J. Eldridge and Elizabeth R. Stanway

in Monthly Notices of the Royal Astronomical Society

Published on behalf of The Royal Astronomical Society

Volume 419, issue 1, pages 479-489
Published in print January 2012 | ISSN: 0035-8711
Published online December 2011 | e-ISSN: 1365-2966 | DOI: http://dx.doi.org/10.1111/j.1365-2966.2011.19713.x
The effect of stellar evolution uncertainties on the rest-frame ultraviolet stellar lines of C iv and He ii in high-redshift Lyman-break galaxies

Show Summary Details

Preview

Young, massive stars dominate the rest-frame ultraviolet (UV) spectra of star-forming galaxies. At high redshifts (z > 2), these rest-frame UV features are shifted into the observed-frame optical and a combination of gravitational lensing, deep spectroscopy and spectral stacking analysis allows the stellar population characteristics of these sources to be investigated. We use our stellar population synthesis code Binary Population and Spectral Synthesis (bpass) to fit two strong rest-frame UV spectral features in published Lyman-break galaxy spectra, taking into account the effects of binary evolution on the stellar spectrum. In particular, we consider the effects of quasi-homogeneous evolution (arising from the rotational mixing of rapidly rotating stars), metallicity and the relative abundance of carbon and oxygen on the observed strengths of He iiλ1640 Å and C ivλ1548, 1551 Å spectral lines. We find that Lyman-break galaxy spectra at z ∼ 2–3 are best fitted with moderately sub-solar metallicities, and with a depleted carbon-to-oxygen ratio. We also find that the spectra of the lowest metallicity sources are best fitted with model spectra in which the He ii emission line is boosted by the inclusion of the effect of massive stars being spun-up during binary mass transfer so these rapidly rotating stars experience quasi-homogeneous evolution.

Keywords: binaries: general; stars: evolution; stars: Wolf–Rayet; galaxies: high redshift; galaxies: starburst; galaxies: stellar content

Journal Article.  7031 words.  Illustrated.

Subjects: Astronomy and Astrophysics

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.