JWST’s PEARLS: A

We present JWST NIRSpec integral field spectroscopy observations of the z = 5. 89 quasar NDWFS J1425+3254 from 0. 6–5. 3 μm, covering the rest-frame ultraviolet and optical at a spectral resolution of R ∼ 100. The quasar has a black hole mass of M₁₇= (1. 4^+3. 1-₁. ₀) 10⁹ M⊙ and an Eddington ratio of L₁₎₋/L₄₃₃=0. 3^+0. 6-₀. ₂, as implied from the broad Balmer Hα and Hβ lines. The quasar host has significant ongoing obscured star formation, as well as a quasar-driven outflow with velocity 6050^+460-₆₃₀ km s−1 and ionised outflow rate of 1650^+130-₁₂₃₀ M⊙ yr−1. This is possibly one of the most extreme outflows in the early Universe. The data also reveal that two companion galaxies are merging with the quasar host. The north-eastern companion galaxy is relatively old and very massive, with a luminosity-weighted stellar age of 65^+9-₄ Myr, stellar mass of (3. 6^+0. 6-₀. ₃) 10^11\, M_, and star-formation rate (SFR) of ∼15–30 M⊙ yr−1. A bridge of gas connects this companion galaxy and the host, confirming their ongoing interaction. A second merger is occurring between the quasar host and a much younger companion galaxy to the south, with a stellar age of 6. 7 ± 1. 8 Myr, stellar mass of (1. 9 ± 0. 4) ×1010 M⊙, and SFR of ∼40–65 M⊙ yr−1. There is also another galaxy in the field, likely in the foreground at z = 1. 135, which could be gravitationally lensing the quasar with a magnification of 1 < μ < 2 and, thus, < 0. 75 mag. Overall, the system is a ‘train-wreck’ merger of three galaxies, with star formation and extreme quasar activity that were likely triggered by these ongoing interactions.