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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present kinematic and photometric evidence for an accretion event in thehalo of the cD galaxy M87 in the last Gyr. Using velocities for ~300 planetarynebulas (PNs) in the M87 halo, we identify a chevron-like substructure in thePN phase-space. We implement a probabilistic Gaussian mixture model to identifythe PNs that belong to the chevron. From analysis of deep V-band images of M87,we find that the region with the highest density of PNs associated to thechevron, is a crown-shaped substructure in the optical light. We assign a totalof N_(PN,sub)=54 to the substructure, which extends over ~50 kpc along themajor axis where we also observe radial variations of the ellipticity profileand a colour gradient. The substructure has highest surface brightness in a20kpc x 60kpc region around 70 kpc in radius. In this region, it causes anincrease in surface brightness by >60%. The accretion event is consistent witha progenitor galaxy with a V-band luminosity of L=2.8\pm1.0 x 10^9 L_(sun,V), acolour of (B-V)=0.76\pm0.05, and a stellar mass of M=6.4\pm2.3 x 10^9 M_sun.The accretion of this progenitor galaxy has caused an important modification ofthe outer halo of M87 in the last Gyr. By itself it is strong evidence that thegalaxy's cD halo is growing through the accretion of smaller galaxies aspredicted by hierarchical galaxy evolution models.

The build-up of the cD halo of M87 - evidence for accretion in the last Gyr