Models of Multi-component Splash Bridges in Face-on Galaxy Disc Collisions. (arXiv:1903.12323v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Yeager_T/0/1/0/all/0/1">Travis Yeager</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Struck_C/0/1/0/all/0/1">Curtis Struck</a>
We use an inelastic particle code with shocks and cooling calculated on a
subgrid level to study the gas in direct collisions between galaxy discs. The
interstellar media (ISM) of the discs are modeled with continuous thermal
phases. The models produce many unique structures, ranging from central bridge
discs to swirled sheets, which resemble those observed in interacting galaxies.
These morphologies are sensitive to the rotation, relative mass, disc offsets
and the gas structure in the discs. In the case of the Taffy galaxies – NGC
12914/15, extensive observations have revealed radio continuum emitting gas, HI
gas, hot X-rays from hot diffuse gas and more molecular Hydrogen than exists in
the Milky Way coexisting in the bridge. The origins of the molecular Hydrogen
and large asymmetric distribution of ISM are not clear. We show that for small
disc impact parameters, multiple phases of ISM with densities over many orders
of magnitude can be removed from their host galaxies into a Taffy-like bridge.
Depending on the orientation of the discs initial overlap can have a great
affect on the distributions of each phase of ISM. In some cases, the models
also predict the creation of a possible `dark galaxy,’ a large flat region of
dense ISM far from the stellar disc potential of either galaxy.
We use an inelastic particle code with shocks and cooling calculated on a
subgrid level to study the gas in direct collisions between galaxy discs. The
interstellar media (ISM) of the discs are modeled with continuous thermal
phases. The models produce many unique structures, ranging from central bridge
discs to swirled sheets, which resemble those observed in interacting galaxies.
These morphologies are sensitive to the rotation, relative mass, disc offsets
and the gas structure in the discs. In the case of the Taffy galaxies – NGC
12914/15, extensive observations have revealed radio continuum emitting gas, HI
gas, hot X-rays from hot diffuse gas and more molecular Hydrogen than exists in
the Milky Way coexisting in the bridge. The origins of the molecular Hydrogen
and large asymmetric distribution of ISM are not clear. We show that for small
disc impact parameters, multiple phases of ISM with densities over many orders
of magnitude can be removed from their host galaxies into a Taffy-like bridge.
Depending on the orientation of the discs initial overlap can have a great
affect on the distributions of each phase of ISM. In some cases, the models
also predict the creation of a possible `dark galaxy,’ a large flat region of
dense ISM far from the stellar disc potential of either galaxy.
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