Ionized gas kinematics and luminosity profiles of Low-z Lyman Alpha Blobs

Abstract

This work is focused on the characterization of the Seyfert-2 galaxies hosting very large, ultra-luminous narrow-line regions (NLRs) at redshifts z = 0.2-0.34. With a space density of 4.4 Gcp-3 at z ∼0.3, these "Low Redshift Lyman-α Blob"(LAB) host galaxies are amongst the rarest objects in the universe, and represent an exceptional and short-lived phenomenon in the life cycle of active galactic nuclei (AGNs). We present the study of GMOS spectra for 13 LAB galaxies covering the rest frame spectral range 3700-6700 Å. Predominantly, the [OIII]λ5007 emission line radial distribution is as widespread as that of the continuum one. The emission line profiles exhibit FWHM between 300-700 Km s-1. In 7 of 13 cases a broad kinematical component is detected with FWHM within the range 600-1100 Km s-1. The exceptionally high [OIII]λ5007 luminosity is responsible for very high equivalent width reaching 1500 Å at the nucleus.