Abstract
We have compiled a library of stellar Lyman-alpha equivalent widths in O and B stars using the model atmosphere codes CMFGEN and TLUSTY, respectively. The equivalent widths range from about 0 to 30 \AA in absorption for early-O to mid-B stars. The purpose of this library is the prediction of the underlying stellar Lyman-alpha absorption in stellar populations of star-forming galaxies with nebular Lyman-alpha emission. We implemented the grid of individual equivalent widths into the Starburst99 population synthesis code to generate synthetic Lyman-alpha equivalent widths for representative star-formation histories. A starburst observed after 10 Myr will produce a stellar Lyman-alpha line with an equivalent width of $\sim$ -10$\pm$4 \AA in absorption for a Salpeter initial mass function. The lower value (deeper absorption) results for an instantaneous burst, and the higher value (shallower line) for continuous star formation. Depending on the escape fraction of nebular Lyman-alpha photons, the effect of stellar Lyman-alpha on the total profile ranges from negligible to dominant. If the nebular escape fraction is 10%, the stellar absorption and nebular emission equivalent widths become comparable for continuous star formation at ages of 10 to 20 Myr.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
