Interactions among intermediate redshift galaxies. The case of SDSSJ134420.86+663717.8

TL;DR

This study analyzes the properties of two interacting galaxies at intermediate redshift, revealing their black hole masses, activity types, and interaction dynamics through spectroscopy and simulations.

Contribution

It provides detailed spectroscopic analysis of the galaxies, estimates black hole masses, and presents a simple N-body simulation of their interaction.

Findings

One galaxy shows Seyfert 1 activity with broad emission lines.

The other galaxy appears to be star-forming with narrow lines.

Black hole masses are nearly equal at a few times 10^7 solar masses.

Abstract

We present the properties of the central supermassive black holes and the host galaxies of the interacting object SDSSJ134420.86+663717.8. We obtained optical long slit spectroscopy data from the Large Binocular Telescope (LBT) using the Multi Object Double Spectrograph (MODS). Analysing the spectra revealed several strong broad and narrow emission lines of ionised gas in the nuclear region of one galaxy, whereas only narrow emission lines were visible for the second galaxy. The optical spectra were used to plot diagnostic diagrams, deduce rotation curves of the two galaxies, and calculate the masses of the central supermassive black holes. We find that the galaxy with broad emission line features has Seyfert~1 properties, while the galaxy with only narrow emission line features seems to be star-forming in nature. Furthermore, we find that the masses of the central supermassive black holes are almost equal at a few times 10^7 solar mass. Additionally, we present a simple N-body simulation to shed some light on the initial conditions of the progenitor galaxies. We find that for an almost orthogonal approach of the two interacting galaxies, the model resembles the optical image of the system.