Change search
ReferencesLink to record
Permanent link

Direct link
Empirical estimate of Lyα escape fraction in a statistical sample of Lyα emitters
Show others and affiliations
2009 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, Vol. 506, no 2, L1-L4 p.Article in journal (Refereed) Published
Abstract [en]

Context: The Lyman-alpha (Lyα) recombination line is a fundamental tool for galaxy evolution studies and modern observational cosmology. However, subsequent interpretations are still prone to a number of uncertainties. Besides numerical efforts, empirical data are urgently needed for a better understanding of the Lyα escape process. Aims: We empirically estimate the Lyα escape fraction in a statistically significant sample of galaxies in a redshift range z ~ 0 - 0.3. This estimate will constrain interpretations of current high-redshift Lyα observations. Methods: An optical spectroscopic follow-up of a sub-sample of 24 Lyα emitters detected by GALEX at z ~ 0.2 - 0.3, combined with a UV-optical sample of local starbursts, both with matched apertures, allow us to quantify the dust extinction through Balmer lines, and to estimate the Lyα escape fraction from the Hα flux corrected for extinction in the framework of the recombination theory. Results: The global escape fraction of Lyα radiation spans a wide range of values and fesc(Lyα) clearly decreases with increasing nebular dust extinction E(B-V). Several objects show fesc(Lyα) greater than fesc(continuum), which may be taken as observational evidence for a clumpy ISM geometry or for an aspherical ISM. Selection biases and aperture size effects may still prevail between z ~ 0.2 - 0.3 Lyman-alpha emitters (LAEs) and local starbursts and may explain the difference observed for fesc(Lyα).

Place, publisher, year, edition, pages
2009. Vol. 506, no 2, L1-L4 p.
Keyword [en]
galaxies: starburst, galaxies: ISM, ultraviolet: galaxies, ISM: dust, extinction
URN: urn:nbn:se:su:diva-36177DOI: 10.1051/0004-6361/200912787ISI: 000271374800001ISBN: 0004-6361OAI: diva2:288938
Available from: 2010-01-22 Created: 2010-01-22 Last updated: 2010-01-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Östlin, G.
By organisation
Department of Astronomy
In the same journal
Astronomy and Astrophysics

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 15 hits
ReferencesLink to record
Permanent link

Direct link