Abstract
Lyman α (Lyα) is the intrinsically most powerful spectral probe of ongoing star formation, and the only one easily accessible at redshifts z > 2.5. For low mass galactic building blocks which have low luminosities from hot dust, Lyα is currently the only probe available. However, its large absorption cross section in neutral hydrogen leads to strong radiative transfer effects and the interpretation of the line strength is far from straightforward. I will present results from two studies aimed at improving our understanding of Lyα emission from galaxies: a Hubble Space Telescope (HST) imaging project of spatially resolved Lyα, Hα and continuum in a small number of galaxies in the local universe, and a combined study of Lyα and Hα from an identical cosmic volume at z = 2.2. I will also outline LARS a new major Lyα imaging study of galaxies in the local universe that will be carried out with HST in cycle 18. Studies at high spatial resolution of nearby starburst galaxies reveal the presence of very massive star clusters where a significant fraction of the star formation takes place. In the context of dwarf galaxies, we have studied a sample of four luminous blue compact galaxies with the HST and found that they seem to be the most efficient cluster formers of all galactic systems. We also note the presence of a near infrared flux excess that seems to ubiquitous in young clusters.
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Notes
- 1.
For access to the calibrated Lyα images, go to: http://ttt.astro.su.se/projects/Lyman-alpha.
References
Adamo, A.: Super Star Clusters in Blue Compact Galaxies: Evidence for a near-infrared flux excess and properties of the starburst phase, PhD thesis, Stockholm University (2011)
Adamo A., Östlin G., Zackrison E., Hayes M.: The Massive Star Clusters in the Dwarf Merger ESO 185-IG13: is the Red Excess Ubiquitous in Starbursts?, MNRAS 414, 1793
Cumming, R., Fathi, K., Östlin, G., Marquart, T., Marquez, I., Masegosa, J., Bergvall, N., Amram, P.: Stellar dynamics of blue compact galaxies. II. Further indications of a merger in ESO 338-IG04. A&A 479, 725 (2008)
Giavalisco, M., Koratkar, A., Calzetti, D.: Obscuration of Lyα Photons in Star-forming Galaxies. ApJ 466, 831 (1996)
Green, J.: HST GTO proposal 11522
Hayes, M., Östlin, G., Atek, H., Kunth, D., Mas-Hesse, J.M., Kunth, D., Leitherer, C., Jimenéz-Bailón, E., Adamo, A.: The escape of Lyman photons from a young starburst: the case of Haro 11. MNRAS 382, 1465 (2007)
Hayes, M., Östlin, G., Schaerer, D., Mas-Hesse, J.M., Leitherer, C., Atek, H., Kunth, D., Verhamme, A., de Bassor, S., Melinder, J.: Escape of about five per cent of Lyman-α photons from high-redshift star-forming galaxies. Nature 464, 562 (2010)
Hayes, M., Schaerer, D., Östlin, G., Mas-Hesse, J.M., Atek, H., Kunth D.: On the Redshift Evolution of the Lyα Escape Fraction and the Dust Content of Galaxies. ApJ 730, 8 (2011)
Heckman, T., Hoopes, C., Seibert, M., et al.: The properties of Ultraviolet-luminous galaxies at the Current Epoch. ApJ 619, L35 (2005)
Kunth, D., Mas-Hesse, J.M., Terlevich, E., Terlevich, R., Lequeux, J., Fall, S.M.: HST study of Lyman-alpha emission in star-forming galaxies: the effect of neutral gas flows. A&A 334, 11 (1998)
Partridge, R.B, Peebles, P.J.E.: Are young galaxies visible? ApJ 147, 868 (1967)
Reines, A., Johnson, K, Goss, W.M.: Emerging massive star clusters revealed: High-resolution imaging of NGC 4449 from the Radio to the Ultraviolet. ApJ 135, 2222 (2008)
Östlin, G.: Massive star clusters in dwarf starburst galaxies, in massive stellar clusters. In: Lancon, A., Boily, C. (eds.) ASP Conf Series 211, p. 63 (1999)
Östlin, G., Amram, P., Bergvall, N., Masegosa, J., Boulesteix, J., Marquez, I.: Dynamics of blue compact galaxies, as revealed by their Hα velocity fields. II. Mass models and the starburst triggering mechanism. A&A 374, 800 (2001)
Östlin, G., Zackrisson, E., Bergvall, N., Rönnback, J.: The temporal and spatial evolution of the starburst in ESO 338-IG04 as probed by its star clusters. A&A 408, 887 (2003)
Steidel, C., Bogosavljević, M., Shapley, A., Kollmeier, J., Reddy, N., Erb, D., Pettini, M.: Diffuse Lyman alpha emitting halos: A generic property of high redshift star forming galaxies, ApJ 736, 160
Acknowledgements
I thank my collaborators, in particular Matthew Hayes and Angela Adamo, for their contributions to the work presented in this paper; and all the local organisers, in particular Polis Papaderos, for a very nice arrangement.
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Östlin, G. (2012). Lyman α Emission and Super-Star Clusters in Dwarf Galaxies. In: Papaderos, P., Recchi, S., Hensler, G. (eds) Dwarf Galaxies: Keys to Galaxy Formation and Evolution. Astrophysics and Space Science Proceedings. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-22018-0_27
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