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

While Norma (ACO3627) is the richest cluster in the Great Attractor (GA)region, its role in the local dynamics is poorly understood. The Norma clusterhas a mean redshift (z_CMB) of 0.0165 and has been proposed as the "core" ofthe GA. We have used the Ks-band Fundamental Plane (FP) to measure Normacluster's distance with respect to the Coma cluster. We report FP photometryparameters (effective radii and surface brightnesses), derived from ESO NTTSOFI images, and velocity dispersions, from AAT 2dF spectroscopy, for 31early-type galaxies in the cluster. For the Coma cluster we use 2MASS imagesand SDSS velocity dispersion measurements for 121 early-type galaxies togenerate the calibrating FP dataset. For the combined Norma-Coma sample wemeasure FP coefficients of a=1.465+/-0.059 and b=0.326+/-0.020. We find an rmsscatter, in log(central velocity dispersion) of 0.08 dex which corresponds to adistance uncertainty of 28% per galaxy. The zero point offset between Norma'sand Coma's FPs is 0.154+/-0.014 dex. Assuming that the Coma cluster is at restwith respect to the cosmic microwave background frame and z_CMB(Coma)=0.0240,we derive a distance to the Norma cluster of 5026+/-160 km/s, and the derivedpeculiar velocity is -72+/-170 km/s, i.e., consistent with zero. This is lowerthan previously reported positive peculiar velocities forclusters/groups/galaxies in the GA region and hence the Norma cluster mayindeed represent the GA's "core".

The Norma cluster (ACO3627) -- III. The Distance and Peculiar Velocity via the Near-Infrared Ks-band Fundamental Plane