Ram pressure stripping of tilted galaxies

Abstract

Context. Ram pressure stripping of galaxies in clusters can yield gas deficient disks. Previous numerical simulations based on various approaches suggested that, except for near edge-on disk orientations, the amount of stripping depends very little on the inclination angle. Aims. Following our previous numerical and analytical study of face-on stripping, we extend the set of parameters with the disk tilt angle and explore in detail the effects of the ram pressure on the interstellar content (ISM) of tilted galaxies that orbit in various environments of clusters, with compact or extended distributions of the intra-cluster medium (ICM). We further study how results of numerical simulations could be estimated analytically. To isolate the effect of inclination, galaxies on strictly radial orbits are considered. Methods. A grid of numerical simulations with varying parameters is produced using the tree/SPH code GADGET with a modified method for calculating the ISM-ICM interaction. These SPH calculations extend the set of existing results obtained from different codes using various numerical techniques. Results. The simulations confirm the general trend of less stripping at orientations close to edge-on. The dependence on the disk tilt angle is more pronounced for compact ICM distributions, however it almost vanishes for strong ram pressure pulses. Although various hydrodynamical effects are present in the ISM-ICM interaction, the main quantitative stripping results appear to be roughly consistent with a simple scenario of momentum transfer from the encountered ICM. This behavior can also be found in previous simulations. To reproduce the numerical results we propose a fitting formula depending on the disk tilt angle and on the column density of the encountered ICM. Such a dependence is superior to that on the peak ram pressure used in previous simple estimates.

A History of H i Stripping in Virgo: A Phase-space View of VIVA Galaxies

“…Roediger & Brüggen 2006;Jáchym et al 2009), but this effect is not taken into account in our calculation. The central surface gas density was estimated following the prescription of Jaffé et al (2015), adopting a disk scale-length of ∼0.5 kpc, the median disk scale-length of the reference sample.…”

Molecular Gas Dominated 50 kpc Ram Pressure Stripped Tail of the Coma Galaxy D100*

“…Numerical simulations have suggested that (close-to) edge-on ram pressure stripping is less efficient than faceon or only slightly inclined stripping (e.g., Jáchym et al 2009;Roediger et al 2006). D100 however has likely been experiencing very strong (near pericenter) ram pressure in which case stripping saturates and the stripping efficiency difference between edge-on and face-on stripping disappears (cf., Jáchym et al 2009). …”

Search for cold and hot gas in the ram pressure stripped Virgo dwarf galaxy IC 3418

“…Some of the denser gas in Fig. 11 is released only after maximum ram pressure, but this is part of material that had already been pushed out of the disk plane to the halo region, and will eventually fall back to the disk (see Jáchym et al 2009, for details). Although our calculations depend on the adopted values of the free orbital parameters not constrained by observations and on the total mass of the galaxy, the results are consistent with what is expected from other simulations and existing observations of galaxies in clusters of the size of Virgo (Kenney & Young 1989;Boselli et al 2002;Fumagalli & Gavazzi 2008): it is not possible to directly strip the dense (molecular) clouds, so they must have been removed from IC3418 in some other way that we will discuss later.…”