2 research outputs found
Detection of the Far-infrared [O III] and Dust Emission in a Galaxy at Redshift 8.312: Early Metal Enrichment in the Heart of the Reionization Era
We present the Atacama Large Millimeter/submillimeter Array (ALMA) detection
of the [O III] 88 m line and rest-frame 90 m dust continuum emission
in a Y-dropout Lyman break galaxy (LBG), MACS0416_Y1, lying behind the Frontier
Field cluster MACS J0416.1-2403. This [O III] detection confirms the LBG with a
spectroscopic redshift of , making this object one of
the furthest galaxies ever identified spectroscopically. The observed 850
m flux density of Jy corresponds to a de-lensed total
infrared (IR) luminosity of if assuming a dust temperature of K and an
emissivity index of , yielding a large dust mass of . The ultraviolet-to-far IR spectral energy distribution modeling
where the [O III] emissivity model is incorporated suggests the presence of a
young ( Myr), star-forming (SFR yr), moderately metal-polluted ()
stellar component with a mass of . An
analytic dust mass evolution model with a single episode of star-formation does
not reproduce the metallicity and dust mass in Myr,
suggesting a pre-existing evolved stellar component with and Gyr as the origin of the
dust mass.Comment: Accepted by ApJ. 18 pages, 10 figures, 5 table