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Arxiv: VODKA-JWST: A 3.8 kpc dual quasar at cosmic noon in a powerful starburst galaxy with JWST/MIRI IFU Published: 3/6/2024 9:18:21 PM Updated: 3/10/2024 6:18:18 AM

Paper abstract: Dual quasars, two active supermassive black holes at galactic scales,represent crucial objects for studying the impact of galaxy mergers and quasaractivity on the star formation rate (SFR) within their host galaxies,particularly at cosmic noon when SFR peaks. We present JWST/MIRI mid-infraredintegral field spectroscopy of J074922.96+225511.7, a dual quasar with aprojected separation of 3.8 kilo-parsec at a redshift z of 2.17. We detectspatially extended [Fe II] 5.34\rm \mum and polycyclic aromatic hydrocarbon(PAH) 3.3\mum emissions from the star formation activity in its host galaxy.We derive the SFR of 10^{3.0\pm0.2} M_{\odot} yr^{-1} using PAH3.3\mum, which is five times higher than that derived from the cutoffluminosity of the infrared luminosity function for galaxies at z~2. Whilethe SFR of J0749+2255 agrees with that of star-forming galaxies of comparablestellar mass at the same redshifts, its molecular gas content falls short ofexpectations based on the molecular Kennicutt-Schmidt law. This discrepancy mayresult from molecular gas depletion due to the longer elevated stage of starformation, even after the molecular gas reservoir is depleted. We do notobserve any quasar-driven outflow that impacts PAH and [Fe II] in the hostgalaxy based on the spatially resolved maps. From the expected flux inPAH-based star formation, the [Fe II] line likely originates from thestar-forming regions in the host galaxy. Our study highlights the stardustnature of J0749+2255, indicating a potential connection between the dual quasarphase and intense star formation activities.