Flaring up of the Compact Cloud G2 during the Close Encounter with Sgr A*

TL;DR

This paper presents a 3D simulation of the gas cloud G2's close encounter with Sgr A*, predicting a significant flare due to tidal forces, which can be observed in near-infrared.

Contribution

It provides the first detailed 3D simulation of G2's pericenter passage around Sgr A*, revealing the cloud's tidal stretching, compression, and resulting luminosity increase.

Findings

G2 is stretched along its orbit by tidal forces.

The cloud experiences strong vertical compression and heating.

Bolometric luminosity peaks at approximately 100 solar luminosities.

Abstract

A compact gas cloud G2 is predicted to reach the pericenter of its orbit around the super massive black hole (SMBH) of our galaxy, Sagittarius A* (Sgr A*). This event will give us a rare opportunity to observe the interaction between SMBH and gas around it. We report the result of the fully three-dimensional simulation of the evolution of G2 during the first pericenter passage. The strong tidal force by the SMBH stretches the cloud along its orbit, and compresses it strongly in the vertical direction, resulting in the heating up and flaring up of the cloud. The bolometric luminosity will reach the maximum of $\sim100 L_{\odot}$. This flare should be easily observed in the near infrared.