Change search
ReferencesLink to record
Permanent link

Direct link
Stockholm University, Faculty of Science, Department of Astronomy. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
Show others and affiliations
2013 (English)In: Astrophysical Journal Letters, ISSN 2041-8205, Vol. 765, no 2, L27- p.Article in journal (Refereed) Published
Abstract [en]

We report on new imaging observations of the Lyman alpha emission line (Ly alpha), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample. We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Ly alpha, H alpha, and the far ultraviolet continuum. We show that Ly alpha is emitted on scales that systematically exceed those of the massive stellar population and recombination nebulae: as measured by the Petrosian 20% radius, RP20, Ly alpha radii are larger than those of H alpha by factors ranging from 1 to 3.6, with an average of 2.4. The average ratio of Ly alpha-to-FUV radii is 2.9. This suggests that much of the Ly alpha light is pushed to large radii by resonance scattering. Defining the Relative Petrosian Extension of Ly alpha compared to H alpha, xi(Ly alpha) = R-P20(Ly alpha)/R-P20(H alpha), we find xi(Ly alpha) to be uncorrelated with total Ly alpha luminosity. However, xi(Ly alpha) is strongly correlated with quantities that scale with dust content, in the sense that a low dust abundance is a necessary requirement (although not the only one) in order to spread Ly alpha photons throughout the interstellar medium and drive a large extended Ly alpha halo.

Place, publisher, year, edition, pages
2013. Vol. 765, no 2, L27- p.
Keyword [en]
cosmology: observations, galaxies: evolution, galaxies: formation, galaxies: starburst, radiative transfer
National Category
Astronomy, Astrophysics and Cosmology
Research subject
URN: urn:nbn:se:su:diva-88993DOI: 10.1088/2041-8205/765/2/L27ISI: 000315489100003OAI: diva2:615381
Knut and Alice Wallenberg FoundationSwedish Research Council


Available from: 2013-04-10 Created: 2013-04-08 Last updated: 2015-01-05Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Östlin, GöranDuval, FlorentGuaita, LuciaMelinder, JensSandberg, Andreas
By organisation
Department of AstronomyThe Oskar Klein Centre for Cosmo Particle Physics (OKC)
In the same journal
Astrophysical Journal Letters
Astronomy, Astrophysics and Cosmology

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: 39 hits
ReferencesLink to record
Permanent link

Direct link