2005ApJ...634L.125M

We report the discovery of a large-scale coherent filamentary structure of Lyα emitters in the redshift space at z=3.1. We carried out spectroscopic observations to map the three-dimensional structure of the beltlike feature of the Lyα emitters discovered by our previous narrowband imaging observations centered on the protocluster at z=3.1. The feature was found to consist of at least three physical filaments connecting with each other. The result is in qualitative agreement with the prediction of the ``biased'' galaxy formation theories that galaxies preferentially formed in large-scale filamentary or sheetlike mass overdensities in the early universe. We also found that the two known giant Lyα emission-line nebulae showing high star formation activities are located near the intersection of these filaments, which presumably evolves into a massive cluster of galaxies in the local universe. This may suggest that massive galaxy formation occurs at a characteristic place in the surrounding large-scale structure at high redshift.