The surprising relationship between Lyman break galaxy spectroscopic features, environment, and kinematics

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• Jeff Cooke (Swinburne)
• Friday 15 July 2011, 11:30-12:30
• Kavli LMR, IoA.

If you have a question about this talk, please contact Dr. Manda Banerji.

I will present results from our program investigating the spatial distribution of LBGs exhibiting different spectroscopic features that has uncovered direct links to their environment and kinematics. Motivated by our recent work investigating interacting z$\sim$3 LBGs, we divide the LBG population into two sub-types: one that exhibits dominant Lyman-alpha absorption and broad/strong interstellar features (termed aLBGs) and one that exhibits dominant Lyman-alpha emission and weak/narrow interstellar features (eLBGs). We use a novel broadband color-magnitude technique, tested using $\sim$1000 Keck spectra, to generate highly pure and large ($\sim$10000) photometric samples of aLBGs and eLBGs in the Canada-France-Hawaii Telescope Legacy Survey Deep fields. The large numbers enable a detailed investigation of the spatial distributions of the two LBG sub-types from large to very small scales using their two-point correlation functions. We see a highly significant difference in the behavior of the two auto-correlation functions indicating that aLBGs typically reside in proto- groups, whereas eLBGs typically reside in the field. In addition, an anti-correlation component in the aLBG/eLBG cross-correlation further signifies the intrinsic differences in spatial locations of the two sub-types. The observed bimodality in the full LBG population – highlighted by these two sub- populations – appears to trace the early formation of the red sequence and blue cloud of galaxies observed locally. Finally, and equally surprising, analysis of IFU studies of z$\sim$2-3 LBGs compiled from the literature find that aLBGs are best fit to disk models and eLBGs to interacting/merging and compact dispersion dominated systems.

This talk is part of the Galaxies Discussion Group series.

This talk is included in these lists:

• Combined External Astrophysics Talks DAMTP
• Cosmology, Astrophysics and General Relativity
• Galaxies Discussion Group
• Institute of Astronomy Talk Lists
• Kavli Institute for Cosmology Talk Lists
• Kavli LMR, IoA

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