Virgo Galaxies with Long One-sided H i Tails

Abstract

In a new H i imaging survey of Virgo galaxies (VIVA: VLA Imaging of Virgo galaxies in Atomic gas), we find seven spiral galaxies with long H i tails. The morphology varies, but all the tails are extended well beyond the optical radii on one side. These galaxies are found in intermediate-to low-density regions (0.6-1 Mpc in projection from M87). The tails are all pointing roughly away from M87, suggesting that these tails may have been created by a global cluster mechanism. While the tidal effects of the cluster potential are too small, a rough estimate suggests that simple ram pressure stripping could have indeed formed the tails in all but two cases. At least three systems show H i truncation to within the stellar disk, providing evidence of a gas-gas interaction. Although most of these galaxies do not appear disturbed optically, some have close neighbors, suggesting that tidal interactions may have moved gas outward, making it more susceptible to the intracluster medium ram pressure or viscosity. Indeed, a simulation study of one of the tail galaxies, NGC 4654, suggests that the galaxy is most likely affected by the combined effect of a gravitational interaction and ram pressure stripping. We conclude that these one-sided H i tail galaxies have recently arrived in the cluster, falling in on highly radial orbits. It appears that galaxies begin to lose their gas already at intermediate distances from the cluster center through ram pressure or turbulent viscous stripping and tidal interactions with their neighbors, or a combination of both.

Connecting optical and X-ray tracers of galaxy cluster relaxation

“…Finally, tidal interactions can also influence gas content through direct stripping or by transporting gas outwards allowing it to be more easily stripped by other mechanisms (e.g. Mayer et al 2006;Chung et al 2007). It's generally accepted that these mechanisms can act on galaxies in dense environments, though the relative bal-ance between different mechanisms in different environments remains an outstanding question.…”

H i debris in the IC 1459 galaxy group

“…The high density of galaxies in clusters together with their high velocity dispersion typically lead to significant gas stripping, particularly from the outer discs of gas-rich spirals, resulting in mainly H i-deficient galaxies near the cluster centre (Chung et al 2007(Chung et al , 2009. The observed H i filaments in, for example, Virgo and Ursa Major (Oosterloo & van Gorkom 2005;Boselli & Gavazzi 2006;Verheijen & Zwaan 2001;Wolfinger et al 2013) hint at the disruptive processes under way, while providing fuel for the formation of new dwarf galaxies from the tidal debris (Duc et al 2004;Lee-Waddell et al 2016).…”

Warm gas in and around simulated galaxy clusters as probed by absorption lines

“…The flow of gas into and out of galaxies within clusters, and into the cluster itself, is strongly affected by the cluster environment. Our understanding of the competing processes involved is still forming, from galaxy level processes such as galactic outflows and inflows to cluster specific processes such as rampressure stripping, galaxy mergers, galaxy harassment, and starvation (e.g., Cayatte et al, 1990;Vollmer et al, 2001; Lewis et al, 2002;Roediger & Hensler, 2005;Chung et al, 2007;Tonnesen, Bryan & van Gorkom, 2007;Yoon et al, 2012). In addition, our understanding of gas flows onto clusters from IGM filaments is incomplete.…”