THE LYMAN ALPHA REFERENCE SAMPLE: EXTENDED LYMAN ALPHA HALOS PRODUCED AT LOW DUST CONTENT

Journal Article · Sun Mar 10 00:00:00 EST 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/765/2/L27· OSTI ID:22130836

Hayes, Matthew ^[1]; Oestlin, Goeran; Duval, Florent; Guaita, Lucia; Melinder, Jens; Sandberg, Andreas ^[2]; Schaerer, Daniel ^[3]; Verhamme, Anne; Orlitova, Ivana ^[4]; Mas-Hesse, J. Miguel; Oti-Floranes, Hector ^[5]; Adamo, Angela ^[6]; Atek, Hakim ^[7]; Cannon, John M. ^[8]; Herenz, E. Christian ^[9]; Kunth, Daniel ^[10]; Laursen, Peter ^[11]

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1. Universite de Toulouse, UPS-OMP, IRAP, Toulouse (France)
2. Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden)
3. CNRS, IRAP, 14, avenue Edouard Belin, F-31400 Toulouse (France)
4. Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, CH-1290 Versoix (Switzerland)
5. Centro de Astrobiologia (CSIC-INTA), Departamento de Astrofisica, POB 78, 28691 Villanueva de la Canada (Spain)
6. Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)
7. Laboratoire d'Astrophysique, Ecole Polytechnique Federale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland)
8. Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States)
9. Leibniz-Institut fuer Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany)
10. Institut d'Astrophysique de Paris, UMR 7095 CNRS and UPMC, 98 bis Bd Arago, F-75014 Paris (France)
11. Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)

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, R{sub P20}, 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}{sub Ly{alpha}} = R {sup Ly{alpha}}{sub P20}/R {sup H{alpha}}{sub P20}, we find {xi}{sub Ly{alpha}} to be uncorrelated with total Ly{alpha} luminosity. However, {xi}{sub 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.

• OSTI ID: 22130836
• Journal Information: Astrophysical Journal Letters, Vol. 765, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
COSMOLOGY
DUSTS
FAR ULTRAVIOLET RADIATION
GALAXIES
IMAGES
LUMINOSITY
LYMAN LINES
NEBULAE
PHOTONS
RADIANT HEAT TRANSFER
RECOMBINATION
RED SHIFT
RESCATTERING
RESONANCE SCATTERING
SPACE
TELESCOPES