%0 Generic %1 hayes2013lyman %A Hayes, Matthew %A Östlin, Göran %A Schaerer, Daniel %A Verhamme, Anne %A Mas-Hesse, J. Miguel %A Adamo, Angela %A Atek, Hakim %A Cannon, John M. %A Duval, Florent %A Guaita, Lucia %A Herenz, E. Christian %A Kunth, Daniel %A Laursen, Peter %A Melinder, Jens %A Orlitová, Ivana %A Otí-Floranes, Héctor %A Sandberg, Andreas %D 2013 %K dust lyalpha scatter size %R 10.1088/2041-8205/765/2/L27 %T The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Content %U http://arxiv.org/abs/1303.0006 %X We report on new imaging observations of the Lyman alpha emission line (Lya), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample (LARS). We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Lya, Halpha, and the far ultraviolet continuum. We show that Lya is emitted on scales that systematically exceed those of the massive stellar population and recombination nebulae: as measured by the Petrosian 20 percent radius, RP20, Lya radii are larger than those of Halpha by factors ranging from 1 to 3.6, with an average of 2.4. The average ratio of Lya-to-FUV radii is 2.9. This suggests that much of the Lya light is pushed to large radii by resonance scattering. Defining the "Relative Petrosian Extension" of Lya compared to Halpha, \xi_ext = RP20_Lya / RP20_Ha, we find \xi_ext to be uncorrelated with total Lya luminosity. However \xi_ext 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 Lya photons throughout the interstellar medium and drive a large extended Lya halo.

@misc{hayes2013lyman, abstract = {We report on new imaging observations of the Lyman alpha emission line (Lya), performed with the Hubble Space Telescope, that comprise the backbone of the Lyman alpha Reference Sample (LARS). We present images of 14 starburst galaxies at redshifts 0.028 < z < 0.18 in continuum-subtracted Lya, Halpha, and the far ultraviolet continuum. We show that Lya is emitted on scales that systematically exceed those of the massive stellar population and recombination nebulae: as measured by the Petrosian 20 percent radius, RP20, Lya radii are larger than those of Halpha by factors ranging from 1 to 3.6, with an average of 2.4. The average ratio of Lya-to-FUV radii is 2.9. This suggests that much of the Lya light is pushed to large radii by resonance scattering. Defining the "Relative Petrosian Extension" of Lya compared to Halpha, \xi_ext = RP20_Lya / RP20_Ha, we find \xi_ext to be uncorrelated with total Lya luminosity. However \xi_ext 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 Lya photons throughout the interstellar medium and drive a large extended Lya halo.}, added-at = {2013-03-04T16:46:04.000+0100}, author = {Hayes, Matthew and Östlin, Göran and Schaerer, Daniel and Verhamme, Anne and Mas-Hesse, J. Miguel and Adamo, Angela and Atek, Hakim and Cannon, John M. and Duval, Florent and Guaita, Lucia and Herenz, E. Christian and Kunth, Daniel and Laursen, Peter and Melinder, Jens and Orlitová, Ivana and Otí-Floranes, Héctor and Sandberg, Andreas}, biburl = {https://www.bibsonomy.org/bibtex/2a7677b4ea54d892b4435fda265d9f120/miki}, description = {[1303.0006] The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Content}, doi = {10.1088/2041-8205/765/2/L27}, interhash = {98d5f05e970694b29bb58eb80c7a3a4f}, intrahash = {a7677b4ea54d892b4435fda265d9f120}, keywords = {dust lyalpha scatter size}, note = {cite arxiv:1303.0006Comment: Published in ApJ Letters ~~ 6 pages using emulateapj, 4 figures ~~ Higher-resolution, larger, nicer jpeg versions of Figures 1 and 2 can be found here: http://xayes.org/pub/press_lars.html}, timestamp = {2013-03-04T16:46:04.000+0100}, title = {The Lyman alpha Reference Sample: Extended Lyman alpha Halos Produced at Low Dust Content}, url = {http://arxiv.org/abs/1303.0006}, year = 2013 }