English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The distinctive cometary X-ray morphology of the recently discovered massivegalaxy cluster "El Gordo" (ACT-CT J0102-4915; z=0.87) indicates that anunusually high-speed collision is ongoing between two massive galaxy clusters.A bright X-ray "bullet" leads a "twin-tailed" wake, with the SZ centroid at theend of the Northern tail. We show how the physical properties of this systemcan be determined using our FLASH-based, N-body/hydrodynamic model, constrainedby detailed X-ray, Sunyaev-Zel'dovich (SZ), and Hubble lensing and dynamicaldata. The X-ray morphology and the location of the two Dark Matter componentsand the SZ peak are accurately described by a simple binary collision viewedabout 480 million years after the first core passage. We derive an impactparameter of ~300 kpc, and a relative initial infall velocity of ~2250 km/secwhen separated by the sum of the two virial radii assuming an initial totalmass of 2.15x10^(15) Msun and a mass ratio of 1.9. Our model demonstrates thattidally stretched gas accounts for the Northern X-ray tail along the collisionaxis between the mass peaks, and that the Southern tail lies off axis,comprising compressed and shock heated gas generated as the massive componentplunges through the main cluster. The challenge for LCDM will be to find out ifthis physically extreme event can be plausibly accommodated when combined withthe similarly massive, high infall velocity case of the "Bullet cluster" andother such cases being uncovered in the new SZ based surveys.

A Hydrodynamical Solution for the "Twin-Tailed" Colliding Galaxy Cluster "El Gordo"