“But after we got the Webb data, I was like, ‘I have no idea what we’re even looking at here, what is all this stuff!’ We spent several weeks just staring and staring at these images.”
A ‘baby’ galaxy merging into a ‘mummy’ galaxy
The Webb images showed at least three galaxies swirling incredibly fast, suggesting the presence of a large amount of mass. This could be one of the “densest-known areas of galaxy formation in the early universe,” said the team.
“What you see here is only a small subset of what’s in the data set,” Zakamska said. “There’s just too much going on here so we first highlighted what really is the biggest surprise. Every blob here is a baby galaxy merging into this mommy galaxy and the colors are different velocities and the whole thing is moving in an extremely complicated way. We can now start to untangle the motions.”
The team is hoping to understand how such dense, “chaotic” galaxy clusters form and is working on follow-up observations.
Extremely red quasars, with bolometric luminosities exceeding 1047 erg s−1, are a fascinating high-redshift population that is absent in the local universe. They are the best candidates for supermassive black holes accreting at rates at or above the Eddington limit, and they are associated with the most rapid and powerful outflows of ionized gas known to date. They are also hosted by massive galaxies. Here we present the first integral field unit (IFU) observations of a high-redshift quasar obtained by the Near Infrared Spectrograph (NIRSpec) on board the James Webb Space Telescope (JWST), which targeted SDSSJ165202.64+172852.3, an extremely red quasar at z=2.94. JWST observations reveal extended ionized gas – as traced by [OIII]λ5007Å – in the host galaxy of the quasar, its outflow, and the circumgalactic medium. The complex morphology and kinematics imply that the quasar resides in a very dense environment with several interacting companion galaxies within projected distances of 10-15 kpc. The high density of the environment and the large velocities of the companion galaxies suggest that this system may represent the core of a forming cluster of galaxies. The system is a good candidate for a merger of two or more dark matter halos, each with a mass of a few 1013 M⊙ and traces potentially one of the densest knots at z∼3.