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Elvis A. Mello-Terencio

Publications and source records attributed to Elvis A. Mello-Terencio.

3 recordsLinked to original sources

When galaxies cross cold fronts: wind tunnel simulations of ram pressure stripping

Cluster collisions and mergers are among the most energetic phenomena in the low redshift Universe. These interactions disturb the intracluster medium creating regions with density and temperature discontinuities, such as sloshing spirals. There is evidence that such environments can influence galaxy evolution. This study aims to understand how a galaxy that crosses an environment with discontinuities in density and temperature can be affected. To this end, a set of simulations was conducted using a wind tunnel setup into which a {MW-like mass} galaxy was inserted. A total of eight models were created, namely two control runs and six with distinct density and temperature transitions along the tunnel, comprising simulations with low density and high density environments. Results show that galaxies lose {considerably} more gas due to the higher density encountered when crossing denser and discontinuous regions in comparison to a constant density environment. The star formation rate exhibits a brief enhancement when the galaxy enters the denser section of the tunnel and {(u-i)} color index also undergoes slight changes, initially becoming bluer. However, even in the simulations with the most intense transitions, changes {in star formation rate and color index} are not substantial, reaching at most 5\% difference in relation to the control models. By the end of the simulation runs, star formation rate and color index are similar to the control runs. These results suggest that crossing intracluster medium discontinuities can induce measurable effects in a galaxy, but these are subtle and short-lived.

astro-ph.GA↗

Quantifying the unwinding due to ram pressure stripping in simulated galaxies

Galaxies moving through the gas of the intracluster medium (ICM) experience ram pressure stripping, which can leave behind a gas tail. When a disk galaxy receives the wind edge-on, however, the characteristic signature is not a typical jellyfish tail, but rather an unwinding of the spiral arms. We aim to quantify such asymmetries both in the gas and in the stellar component of a simulated galaxy. To this end, we simulate a gas-rich star-forming spiral galaxy moving through a self-consistent ICM gas. The amplitude and location of the asymmetries were measured via Fourier decomposition. We found that the asymmetry is much more evident in the gas component, but it is also measurable in the stars. The amplitude tends to increase with time and the asymmetry radius migrates inwards. We found that, when considering the gas, the spiral arms extend much further and are more unwound than the corresponding stellar arms. Characterizing the unwinding via simulations should help inform the observational criteria used to classify ram pressure stripped galaxies, as opposed to asymmetries induced by other mechanisms.

astro-ph.GA↗

Simulating nearly edge-on sloshing in the galaxy cluster Abell 2199

Off-axis collisions between galaxy clusters may induce the phenomenon of sloshing, causing dense gas to be dragged from the cool core of a cluster, resulting in a spiral of enhanced X-ray emission. Abell 2199 displays signatures of sloshing in its core and it is possible that the orbital plane of the collision is seen nearly edge-on. We aim to evaluate whether the features of Abell 2199 can be explained by a sloshing spiral seen under a large inclination angle. To address this, we perform tailored hydrodynamical $N$-body simulations of a non-frontal collision with a galaxy group of $M_{200}=1.6\times10^{13}\,{\rm M_{\odot}}$. We obtain a suitable scenario in which the group passed by the main cluster core 0.8 Gyr ago, with a pericentric separation of 292 kpc. Good agreement is obtained from the temperature maps as well as the residuals from a $β$-model fit to the simulated X-ray emission. We find that under an inclination of $i=70^{\circ}$ the simulation results remain consistent with the observations.

astro-ph.GA↗