Published on 06 March 2019
In section 4. Extragalactic astronomy
A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE).V. Properties of the ionised gas filament of M87
As the central galaxy of the Virgo cluster, M87 presents the benchmark case for the study of how AGNs affect - and are affected by - their environments. This paper presents a comprehensive study of the diffuse gas associated with this giant elliptical with the combination of narrow band filter MEGACAM imaging (H\alpha and [N II]) and high resolution MUSE spectra (60 km/s resolution), a high enough resolution to completely characterize the dynamics of the extended structures. The authors use the imaging to obtain the dust distribution in the extended gas and H I column densities derived from the extinction measures. Individual large filamentary ionized structures are found on scales of kpc, with the velocity ranging over many hundreds of km/s along the line of sight (indicating superimposed features). Evidence is presented for shock interaction of the jets with this gas. Two, not mutually exclusive, scenarios are shown to be consistent with the observations: accretion of gas recently stripped from a companion and interaction of the jet with the cluster and galactic gas.