Subaru Deep Spectroscopy of a Star-forming Companion Galaxy of BR 1202-0725 at z=4.7
Abstract
We present deep spatially-resolved optical spectroscopy of the NW companion galaxy of the quasar BR 1202-0725 at z=4.7. Its rest-frame UV spectrum shows star-forming activity in the nuclear region. The Lyα emission profile is symmetric with wavelength while its line width is unusually wide (FWHM 1100 km s-1) for such a high-z star-forming galaxy. Spectrum taken along the Lyα nebula elongation, which is almost along the minor axis of the companion host galaxy, reveals that off-nuclear Lyα nebulae have either flat-topped or multi-peaked profiles along the extension. All these properties can be understood in terms of superwind activity in the companion galaxy. We also find a diffuse continuum component around the companion, which shows similar morphology to that of Lyα nebula, and is most likely due to scattering of the quasar light at dusty halo around the companion. We argue that the superwind could expel dusty material out to the halo region, making a dusty halo for scattering.
Turn this paper into a full lesson
ArcXiv compiles a staged curriculum from this paper: 8-12 lessons across beginner → advanced, synthesised section guides, visuals, flashcards, a quiz, exercises, and on-demand deep dives per section. Grounded in the abstract, never invented.