Ram-Ppressure Effects on Dense Molecular Arms in the Central Regions of Spiral Galaxies by Intracluster Medium

Abstract

We investigated ram-pressure effects by an intracluster wind on an inner disk of spiral galaxies by a hydrodynamical simulation. Even if the wind is mild and not strong enough to strip the gas disk, the ram pressure disturbs orbits of the inter-arm gas significantly. This results in asymmetric dense molecular arms in the inner few kpc region of a galaxy. This mechanism would explain the asymmetric CO gas distributions in the central regions often observed in Virgo spirals.

To appear in PASJ. 7 pages, 3 gif figures