Superwind model of extended Lyman alpha emitters at high redshift

Abstract

We propose a new model for the extended Ly alpha blobs found recently at high redshift z ~ 3. The observational properties of these blobs are; 1) the observed Ly alpha luminosities are ~ 10^{43} h^{-2} ergs s^{-1}, 2) they appear elongated morphologically, 3) their sizes amount to ~ 100 kpc, 4) the observed line widths amount to ~ 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 Ly alpha blobs (~ 3.4 x 10^{-5} h^3 Mpc^{-3}) may be explained if their present-day counterparts are elliptical galaxies with a luminosity above ~ 1 L^*.