Future collapse of the J0305−3150 z=6.6 protocluster

Ascertain whether the extended, non-virialized z≈6.6 protocluster surrounding the quasar J0305−3150 will eventually collapse into a bound galaxy cluster at later cosmic times, despite its current filamentary morphology and large line-of-sight extent.

Background

The authors identify a filamentary overdensity of [OIII] emitters at 6.5 < z < 6.8 around the quasar J0305−3150, extending over ~10 comoving Mpc on the sky and ∆z ≈ 0.2 along the line of sight, which indicates the structure is not yet virialized.

Because the system is unrelaxed, standard dynamical methods (e.g., virial theorem) cannot be applied to estimate a total halo mass, leaving uncertain the eventual fate of the structure—specifically, whether it will fully collapse into a mature galaxy cluster.

References

Therefore, we cannot use the virial theorem to estimate a total halo mass for this structure, nor can we comment on whether this structure will ever fully collapse into a galaxy cluster.

— A Quasar-Anchored Protocluster at z=6.6 in the ASPIRE Survey: I. Properties of [OIII] Emitters in a 10 Mpc Overdensity Structure (2410.03826 - Champagne et al., 4 Oct 2024) in Section 6.2 (Comparison to simulations)