The Lyα Reference Sample. VIII. Characterizing Lyα Scattering in Nearby Galaxies

Joanna S. Bridge, Matthew Hayes, Jens Melinder, Göran Östlin, Caryl Gronwall, Robin Ciardullo, Hakim Atek, John M. Cannon, Max Gronke, Lucia Guaita, Alex Hagen, Edmund Christian Herenz, Daniel Kunth, Peter Laursen, J. Miguel Mas-Hesse, Stephen A. Pardy

Resultado de la investigación: Contribución a una revistaArtículorevisión exhaustiva

6 Citas (Scopus)

Resumen

We examine the dust geometry and Lyα scattering in the galaxies of the Lyman Alpha Reference Sample (LARS), a set of 14 nearby (0.02 < z < 0.2) Lyα-emitting and starbursting systems with Hubble Space Telescope Lyα, Hα, and Hβ imaging. We find that the global dust properties determined by line ratios are consistent with other studies, with some of the LARS galaxies exhibiting clumpy dust media, while others of them show significantly lower Lyα emission compared to their Balmer decrement. With the LARS imaging, we present Lyα/Hα and Hα/Hβ maps with spatial resolutions as low as ∼40 pc, and use these data to show that in most galaxies, the dust geometry is best modeled by three distinct regions: a central core where dust acts as a screen, an annulus where dust is distributed in clumps, and an outer envelope where Lyα photons only scatter. We show that the dust that affects the escape of Lyα is more restricted to the galaxies' central regions, while the larger Lyα halos are generated by scattering at large radii. We present an empirical modeling technique to quantify how much Lyα scatters in the halo, and find that this "characteristic" scattering distance correlates with the measured size of the Lyα halo. We note that there exists a slight anti-correlation between the scattering distance of Lyα and global dust properties.

Idioma originalInglés
Número de artículo9
PublicaciónAstrophysical Journal
Volumen852
N.º1
DOI
EstadoPublicada - 1 ene 2018
Publicado de forma externa

Áreas temáticas de ASJC Scopus

  • Astronomía y astrofísica
  • Ciencias planetarias y espacial

Huella

Profundice en los temas de investigación de 'The Lyα Reference Sample. VIII. Characterizing Lyα Scattering in Nearby Galaxies'. En conjunto forman una huella única.

Citar esto