The Next Generation Virgo Cluster Survey. IV. NGC 4216: A Bombarded Spiral in the Virgo Cluster

TL;DR

This study uses high-resolution optical imaging to analyze faint stellar structures around NGC 4216, revealing ongoing dwarf galaxy destruction and complex interactions indicative of pre-processing in the Virgo Cluster.

Contribution

It provides detailed physical analysis of low-surface brightness features around NGC 4216, identifying progenitors and suggesting active dwarf galaxy disruption in the Virgo Cluster.

Findings

Identification of multiple stellar streams and plumes.

Evidence of ongoing dwarf galaxy destruction.

Possible formation of second-generation dwarfs within streams.

Abstract

We present an investigation into the origins of a series of interlaced narrow filamentary stellar structures, loops and plumes in the vicinity of the Virgo Cluster, edge-on spiral galaxy, NGC 4216 that were previously identified by the Blackbird Telescope. Using the deeper, higher-resolution and precisely calibrated optical CFHT/MegaCam images obtained as part of the Next Generation Virgo Cluster Survey (NGVS), we confirm the previously identified features and identify a few additional structures. The NGVS data allowed us to make a physical study of these low-surface brightness features and investigate their origin. The likely progenitors of the structures were identified as either already catalogued VCC dwarfs or newly discovered satellites caught in the act of being destroyed. They have the same g-i color index and likely contain similar stellar populations. The alignment of three dwarfs along an apparently single stream is intriguing, and we cannot totally exclude that these are second-generation dwarf galaxies being born inside the filament from the debris of an original dwarf. The observed complex structures, including in particular a stream apparently emanating from a satellite of a satellite, point to a high rate of ongoing dwarf destruction/accretion in the region of the Virgo Cluster where NGC 4216 is located. We discuss the age of the interactions and whether they occurred in a group that is just falling into the cluster and shows signs of so-called "pre-processing" before it gets affected by the cluster environment, or in a group which already ventured towards the central regions of Virgo Cluster.