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

NGC 4993 is the shell galaxy host of the GRB170817A short gamma-ray burst andthe GW170817 gravitational-wave event produced during a binary-neutron-starcoalescence. The galaxy shows signs, including the stellar shells, that it hasrecently accreted a smaller, late-type galaxy. The accreted galaxy might be theoriginal host of the binary neutron star. We measured the positions of thestellar shells of NGC 4993 in an HST/ACS archival image and use the shellpositions to constrain the time of the galactic merger. According to theanalytical model of the evolution of the shell structure in the expectedgravitational potential of NGC 4993, the galactic merger happened at least 200Myr ago, with a probable time roughly around 400 Myr and the estimates higherthan 600 Myr being improbable. This constitutes the lower limit on the age ofthe binary neutron star, because the host galaxy was probably quenched evenbefore the galactic merger, and the merger has likely shut down the starformation in the accreted galaxy. We roughly estimate the probability that thebinary neutron star originates in the accreted galaxy to be around 30%.

NGC 4993, the shell galaxy host of GW170817: constraints on the recent galactic merger