Journal article
The Ly alpha Reference Sample. VIII. Characterizing Ly alpha Scattering in Nearby Galaxies
The Astrophysical journal, Vol.852(1), p.9
01/01/2018
DOI: 10.3847/1538-4357/aa9932
Abstract
We examine the dust geometry and Ly alpha scattering in the galaxies of the Lyman Alpha Reference Sample (LARS), a set of 14 nearby (0.02 < z < 0.2) Ly alpha-emitting and starbursting systems with Hubble Space Telescope Ly alpha, H alpha, and H beta 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 Ly alpha emission compared to their Balmer decrement. With the LARS imaging, we present Ly alpha/H alpha and H alpha/H beta maps with spatial resolutions as low as similar to 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 Ly alpha photons only scatter. We show that the dust that affects the escape of Ly alpha is more restricted to the galaxies' central regions, while the larger Ly alpha halos are generated by scattering at large radii. We present an empirical modeling technique to quantify how much Ly alpha scatters in the halo, and find that this "characteristic" scattering distance correlates with the measured size of the Ly alpha halo. We note that there exists a slight anti-correlation between the scattering distance of Ly alpha and global dust properties.
Details
- Title: Subtitle
- The Ly alpha Reference Sample. VIII. Characterizing Ly alpha Scattering in Nearby Galaxies
- Creators
- Joanna S. Bridge - University of LouisvilleMatthew Hayes - Stockholm UniversityJens Melinder - Stockholm UniversityGoran Ostlin - Stockholm UniversityCaryl Gronwall - Pennsylvania State UniversityRobin Ciardullo - Pennsylvania State UniversityHakim Atek - Institut d'Astrophysique de ParisJohn M. Cannon - Macalester CollegeMax Gronke - University of OsloLucia Guaita - Astronomical Observatory of RomeAlex Hagen - Pennsylvania State UniversityEdmund Christian Herenz - Leibniz Institute for Astrophysics PotsdamDaniel Kunth - Institut d'Astrophysique de ParisPeter Laursen - University of OsloJ. Miguel Mas-Hesse - Ctr Astrobiol CSIC INTA, Dept Astrofis, POB 78, E-28691 Villanueva De La Canada, SpainStephen A. Pardy - University of Wisconsin–Madison
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.852(1), p.9
- Publisher
- IOP Publishing Ltd
- DOI
- 10.3847/1538-4357/aa9932
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Number of pages
- 32
- Grant note
- 131425 / Centre National d'Etudes Spatiales (CNES)/Centre National de la Recherche Scientifique (CNRS) ESP2015-65712-C5-1-R / Spanish MINECO grant; Spanish Government Eberly College of Science Office of the Senior Vice President for Research at the Pennsylvania State University 1615526 / Division Of Astronomical Sciences; Direct For Mathematical & Physical Scien; National Science Foundation (NSF); NSF - Directorate for Mathematical & Physical Sciences (MPS) Swedish Research Council (VR) through the National Science Foundation (NSF) Graduate Research Opportunities Worldwide Fellowship; Swedish Research Council VR; Swedish Research Council Swedish National Space Board (SNSB) AST-1615526 / NSF grant; National Science Foundation (NSF)
- Language
- English
- Date published
- 01/01/2018
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984627199502771
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