Outflow in Overlooked Luminous Quasar: Subaru Observations of AKARI J1757+5907

Abstract

We present Subaru observations of the newly discovered luminous quasar AKARI J1757+5907, which shows an absorption outflow in its spectrum. The absorption consists of 9 distinct troughs, and our analysis focuses on the troughs at ∼-1000 km s^-1 for which we could measure accurate column densities of He I^*, Fe II, and Mg II. We used photoionization models to constrain the ionization parameter, total hydrogen column density, and number density of the outflowing gas. These constraints yielded lower limits for the distance, mass-flow rate, and kinetic luminosity for outflows of 3.7 kpc, 70 M_odot yr^-1, and 2.0 ×10⁴³ erg s^-1, respectively. Such a mass-flow rate value can contribute significantly to metal enrichment of the intra-cluster medium. We found that this moderate velocity outflow is similar to those recently discovered in massive post-starburst galaxies. Finally, we describe the scientific potential of future observations targeting this object.