CFHT UM2019 - Presentation Details

Abstract Details

Title: A Virgo Environmental Survey Tracing Ionised Gas Emission (VESTIGE). A unique dataset to study the role of the environment in the production of long tails with

Presenter: Alessia Longobardi


Structure evolution is now understood to be the products of a Hubble time's worth of merging, accretion, and interaction with the surrounding environment. This history is hidden, however, being quickly mixed into a smooth and apparently featureless distribution of baryons, or by being at surface brightness much fainter than the sky. Owing to its superior sensitivity VESTIGE (Virgo Environmental Survey Tracing Ionised Gas Emission) is a MegaCam@CFHT deep Hα narrow-band imaging survey of the Virgo cluster that offers a unique tool to investigate the regions in space hosting fossil records of structures evolution. The focus of this talk will be on the VESTIGE team effort of studying low surface brightness tails of stripped material through their ionised gas emission (Hα) that also present HI (neutral) and FIR (dust) emission. I will show the analysis for a sample of tens of Virgo galaxies, from the core to the less dense regions of the cluster, and the investigation of the physical conditions necessary for the long tails to be present in the two different gas phases (neutral, ionised) and to fuel star formation. Is there a preferred environments or are there peculiar requirements on the progenitors properties or encounter characteristics to trigger such a phenomenon? Thanks to its depth and extension (covering out to one virial radius) VESTIGE revealed for the first time long tails of ionised gas in several cluster galaxies. Moreover, capitalising on the wealth of multi-frequency data surveying Virgo at good/optimal resolution and sensitivity - e.g., VIVA Survey (VLA Imaging of Virgo in Atomic gas) and Herschel Virgo Cluster Survey (HeVICS) -, it provides the unique data-set to answer these questions.