An interaction scenario of the galaxy pair NGC 3893/96 (KPG 302). A single passage?

TL;DR

This study investigates whether a single passage interaction can explain the spiral structure of galaxy pair NGC 3893/96, using observations and simulations, and suggests multiple passages may be necessary.

Contribution

It combines Fabry-Perot data with N-body/SPH simulations to assess the interaction history and spiral arm formation in galaxy pair KPG 302.

Findings

A single passage can produce a grand design spiral in less than 1 Gyr.

The required satellite mass ratio for this scenario is 1:5.

Multiple passages are likely needed to reconcile mass ratio discrepancies.

Abstract

Using the data obtained previously from Fabry-Perot interferometry, we study the orbital characteristics of the interacting pair of galaxies KPG 302 with the aim to estimate a possible interaction history, the conditions necessary for the spiral arms formation and initial satellite mass. We found by performing N-body/SPH simulations of the interaction that a single passage can produce a grand design spiral pattern in less than 1 Gyr. Althought we reproduce most of the features with the single passage, the required satellite to host mass ratio should be 1:5, which is not confirmed with the dynamical mass estimate made from the measured rotation curve. We conclude that a more realistic interaction scenario would require several passages in order to explain the mass ratio discrepancy.