2025A&A...702A.174M -
Astronomy and Astrophysics, volume 702A174 (2025/10-1)
JWST's PEARLS: A z ≃ 6 quasar in a train-wreck galaxy merger system.
MARSHALL M.A., WINDHORST R.A., FERRAMI G., WILLNER S.P., DEL CARMEN POLLETTA M., KEEL W.C., FAZIO G.G., COHEN S.H., CARLETON T., JANSEN R.A., HONOR R., ORTIZ III R., SUMMERS J., D'SILVA J.C.J., KOEKEMOER A.M., COE D., CONSELICE C.J., DIEGO J.M., DRIVER S.P., FRYE B., GROGIN N.A., PIRZKAL N., ROBOTHAM A., RYAN R.E.Jr, WILLMER C.N.A., YAN H., RICOTTI M., ZITRIN A., ADAMS N.J., CHENG C., WYITHE J.S.B., LIM J., PERNA M., UBLER H., WILLOTT C.J., JONES G., SCHOLTZ J. and MECHTLEY M.
Abstract (from CDS):
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 $ M_\mathrm{{BH}}=(1.4^{+3.1}_{-1.0})\times10^9 $M⊙ and an Eddington ratio of $ L_\mathrm{{Bol}}/L_\mathrm{{Edd}}=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})\times10^{11}\,M_\odot $, 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)×1010M⊙, 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.
Abstract Copyright:
© The Authors 2025
Journal keyword(s):
galaxies: active - galaxies: high-redshift - galaxies: interactions - quasars: emission lines - quasars: supermassive black holes
Simbad objects:
15
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2025A&A...702A.174M and select 'bookmark this link' or equivalent in the popup menu