Superwind Model of Extended Lyalpha Emitters at High Redshift

We propose a new model for the extended Lyalpha blobs found recently at high redshift (z approximately 3). The observational properties of these blobs are as follows: (1) the observed Lyalpha luminosities are approximately 1043 h-2 ergs s-1, (2) they appear elongated morphologically, (3) their sizes amount to approximately 100 kpc, (4) the observed line widths amount to approximately 1000 km s-1, and (5) they are not associated with strong radio continuum sources. All these observational properties seem to be explained in terms of galactic winds driven by successive supernova explosions shortly after the initial burst of massive star formation in the galactic centers. The observed number density of Lyalpha blobs ( approximately 3.4x10-5 h3 Mpc-3) may be explained if their present-day counterparts are elliptical galaxies with a luminosity above approximately 1L*.