English   español  
Please use this identifier to cite or link to this item: http://hdl.handle.net/10261/13014
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE
Exportar a otros formatos:


The escape of Lyman photons from a young starburst: the case of Haro 11

AuthorsHayes, Matthew; Östlin, G.; Atek, Hakim; Kunth, Daniel; Mas-Hesse, J. Miguel ; Leitherer, Claus; Jiménez-Bailón, Elena; Adamo, Angela
KeywordsGalaxies: evolution
Galaxies: individual: Haro 11
Galaxies: star clusters
Ultraviolet: galaxies
Issue Date26-Nov-2007
PublisherRoyal Astronomical Society
Blackwell Publishing
CitationMonthly Notices of the Royal Astronomical Society 382(4): 1465-1480 (2007)
AbstractLyman α (Lyα) is one of the dominant tools used to probe the star-forming galaxy population at high redshift (z). However, astrophysical interpretations of data drawn from Lyα alone hinge on the Lyα escape fraction which, due to the complex radiative transport, may vary greatly. Here, we map the Lyα emission from the local luminous blue compact galaxy Haro 11, a known emitter of Lyα and the only known candidate for low-z Lyman continuum emission. To aid in the interpretation, we perform a detailed ultraviolet and optical multiwavelength analysis and model the stellar population, dust distribution, ionizing photon budget, and star-cluster population. We use archival X-ray observations to further constrain properties of the starburst and estimate the neutral hydrogen column density.
The Lyα morphology is found to be largely symmetric around a single young star-forming knot and is strongly decoupled from other wavelengths. From general surface photometry, only very slight correlation is found between Lyα and Hα, E(B−V) , and the age of the stellar population. Only around the central Lyα bright cluster do we find the Lyα/Hα ratio at values predicted by the recombination theory. The total Lyα escape fraction is found to be just 3 per cent. We compute that ∼90 per cent of the Lyα photons that escape do so after undergoing multiple resonance scattering events, masking their point of origin. This leads to a largely symmetric distribution and, by increasing the distance that photons must travel to escape, decreases the escape probability significantly. While dust must ultimately be responsible for the destruction of Lyα, it plays a little role in governing the observed morphology, which is regulated more by interstellar medium kinematics and geometry. We find tentative evidence for local Lyα equivalent width in the immediate vicinity of star clusters being a function of cluster age, consistent with hydrodynamic studies. We estimate the intrinsic production of ionizing photons and put further constraints of ∼9 per cent on the escaping fraction of photons at 900 Å.
Description16 pages, 9 figures, 8 tables, 1 appendix.-- ISI Article Identifier: 000251672100007.-- ArXiv pre-print available at: http://arxiv.org/abs/0710.2622
Publisher version (URL)http://dx.doi.org/10.1111/j.1365-2966.2007.12482.x
Appears in Collections:(CAB) Artículos
Files in This Item:
File Description SizeFormat 
Lyman_photons.pdf1,15 MBAdobe PDFThumbnail
Show full item record
Review this work

WARNING: Items in Digital.CSIC are protected by copyright, with all rights reserved, unless otherwise indicated.